A Proposed Five Storey School Building With the Use of Fly Ash
Short Description
CE...
Description
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A Proposed Five-Storey School Building with the Use of Fly Ash as an Additive Material for Portland Cement at St. Anthony School, San Andres, Manila
Project By
Magcaleng, Kenneth Rogie D. Mallillin, John Eric A. Punzalan, Jan Jhonnel T.
Submitted to the School of Civil, Environmental and Geological Engineering (SCEGE)
In Partial Fulfillment of the Requirements For the Degree of Bachelor of Science in Civil Engineering
Mapua Institute of Technology
Muralla St., Intramuros, Manila City
December 2012
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Executive Summary
Availability of rooms such as classrooms is one of the major problems arising on schools. Escalating number of population with increasing number of school children enrollees is one of the main factors of lack of classrooms. With this project, we were given the opportunity to provide a design of a private school building for the surrounding and nearby residents of San Andres, Manila. The design of a five-storey school building includes fly ash material added to mortars to minimize the cost of materials in in mixing the cement, day lighting that will be considered and ventilation system in the corridor part of the building in order to minimize the used of energy. The said project provides from an existing of 12 up to 28 numbers of classrooms. There will be an auditorium constructed at the fifth floor of the building. This project will decongest the classrooms of the main private school building and give comfortable learning facility to the students and public school teachers as well.
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Table of Contents Chapter 1: Introduction
1
Chapter 2: Presenting the Challenges
2
2.1 Problem Statement
2
2.2 Project Objective
3
2.3 Design Norms Considered
3
2.4 Major and Minor Areas of Civil Engineering
4
2.5 The Project Beneficiary
4
2.6 The Innovative Approach
4
2.7 The Research Component
5
2.8 The Design Component
5
2.9 Sustainable Development Concept
6
Chapter 3: Environmental Examination Report 3.1 Project Description
7 7
3.1.1 Project Rationale
7
3.1.2 Project Location
7
3.1.3 Project Information
8
3.1.4 Description of Project Phases
9
3.1.5 Pre-construction/Operational Phase
9
3.1.6 Construction Phase
9
3.1.7 Operational Phase
10
3.1.8 Abandonment Phase
11
3.2 Description of Environmental Setting and Receiving
12
Environment
3.2.1 Physical Environment
12
3.2.2 Biological Environment
12
3.2.3 Socio-Cultural, Economic and Political Environment
12
3.2.4 Future Environmental Conditions without the Project
13
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3.3 Impact Assessment and Mitigation
13
3.3.1 Summary Matrix of Predicted Environmental Issues/Impacts and their Level of Significance at Various Stages of Development
13
3.3.2 Brief Discussion of Specific Significant Impacts on the Physical and Biological Resources
14
3.3.3 Brief Discussion of Significant Socio-economic Effects/Impacts of the Project 3.4 Environmental Management Plan
15 16
3.4.1 Summary Matrix of Proposed Mitigation and Enhancement Measures, Estimated Cost and Responsibilities
16
3.4.2 Brief Discussion of Mitigation and Enhancement Measures
18
3.4.3 Monitoring Plan
19
3.4.4 Institutional Responsibilities and Agreements
20
Chapter 4: The Research Component
21
4.1 Introduction
21
4.2 Review of Related Literature
22
4.3 Methodology
32
Chapter 5: Detailed Engineering Design 5.1 Loads and Codes
34 37
5.1.1 Introduction
37
5.1.2 Codes
37
5.1.3 Dead Loads
38
5.1.4 Live Loads
38
5.1.5 Earthquake Loads
41
5.1.6 Wind Loads
41
5.2 Structural Design
5.2.1 Introduction
43 43
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5.2.2 Beam Design
43
5.2.3 Column Design
43
5.2.4 Slab Design
43
5.2.4.1 One Way Slab
43
5.2.4.2 Two Way Slab
44
5.2.5 Design of Trusses
44
5.2.5.1 Design Consideration
44
5.2.5.2 Design of Howe Truss
48
5.2.6 Design of Foundation
54
5.2.6.1 Introduction
58
5.2.7 Design of Concrete Mix
64
Chapter 6: Budget Estimation
74
Chapter 7: Project Schedule
82
Chapter 8: Promotional Material
86
Conclusion and Summary
88
Recommendation
90
Acknowledgement
91
References
92
Appendices
Article Type Paper Beam Design Column Design Slab Design Slump Test Soil Investigation Report Worksheet for Design of Concrete Price List Compression Test of Flyash Concrete Results Original Project Report Assessment Sheet by Panel Members English Editor Assessment and Evaluation Rubric Accomplished Consultation Forms
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Compilation of Assessment Forms (Rubrics) Copy of Engineering Drawings and Plans Copy of Project Poster Photocopy of Receipts Relevant Pictures Other required forms Student Reflections Resume of Each Member
List of Tables, Illustrations, Charts or Graphs Figures
Fig. 3.0 The Vicinity Map of Saint Francis Building
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Fig. 3.1 Map View of the Location of the Proposed Project
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Fig. 5.1 Shorter Direction Top Bar
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Fig. 5.2 Longer Direction Top Bar
60
Fig. 5.3 Shorter Direction Bottom Bar
60
Fig. 5.4 Longer Direction Bottom Bar
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Fig. 5.5 Shorter Direction Bottom Bar Result
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Fig. 5.6 Longer Direction Bottom Bar Result
62
Fig. 5.3 Shorter Direction Top Bar Result
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Fig. 5.4 Longer Direction Top Bar Result
63
Fig. 7.1 Gantt Chart
83
Fig. 7.2 Project Network Diagram
84
Fig. 7.3 Project Calendar
84
Fig. 7.4 Project Team Planner
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Fig. 9.0 Ratio Between Compressive Strength and Time
88
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Tables
Table 1.0 2010 Census and Housing and Population of National Capital Region (NCR), Philippines 2
2
Table 3.1 Summary Matrix of Predicted Environmental Issues/Impacts and their Level of Significance at Various Stages of Development
14
Table 3.2 Summary Matrix of Proposed Mitigation and Enhancement Measures, Estimated Cost and Responsibilities
16
Table 3.3 Monitoring Plan
20
Table 5.3 Support Reactions End Forces
49
Table 5.4 Member End Forces
49
Table 5.5: Summary of Concrete-Mix Parameters from Material Testing Table 5.6 A tabulated Summary of computed values is shown below:
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Chapter 1 Introduction Educational problems in the Philippines have gone through many changes and developments for the past few years. The continuous process made great impact in the lives of millions of Filipinos. Relatively, the changes have given both advantages and disadvantages, the latter causing the downfall of many people. There are numerous questions concerning the issues and problems existing in the Philippine educational system as to how to attain the kind of quality of education that Filipinos have been searching and longing for. The high cost of materials in construction hampered the efforts of different institutions to build new structures. Learning institutions such as schools have small budgets from the government because of the need to fund various other priorities. On the other hand, the private sector in the country has been a major provider of educational services, accounting for about 7.5% of primary-school enrollment, 32% of secondary-school enrollment and about 80% of tertiary-school enrollment. Private schools have proven to be efficient in resource utilization. Per unit costs in private schools are generally lower when compared to public schools. This situation is more evident at the tertiary level. Government regulations have given private education more flexibility and autonomy in recent years, notably by lifting the moratorium on applications for new courses, new schools and conversions, liberalizing the tuition fee policy for private schools, replacing values education for third and fourth years with English, mathematics and natural science at the option of the school, and issuing a revised manual of regulations for private schools last August 1992. In the school year 2001/02, there were 4,529 private elementary schools (out of a total of 40,763) and 3,261 private secondary schools (out of a total of 7,683). In 2002/03, there were 1,297 private higher education institutions (out of a total of 1,470).
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Chapter 2 Presenting the Challenges 2.1 Problem Statement
The area of San Andres, Manila is composed mostly of residential sections with some sections classified as commercial. Students from Paco and Malate study at the school here because it is one of the well-known elementary and secondary schools in Manila. Although the population of Manila (from the table 1.0) does not increase significantly, the numbers of student enrollees has grown further as stated (table1.1).
Table 1.0 2010 Census and Housing and Population of National Capital Region (NCR),
Philippines Total Population
Population Growth Rate
Region/Province/Highly Urbanized City
l-May-90
l-May-00
l-May-10
1990-
2000-
1990-
2000
2010
2010
Philippines
60,703,810
76,506,928
92,337,852
2.34
1.90
2.12
National Capital Region
7,948,392
9,932,560
11,855,975
2.25
1.78
2.02
City of Las Pinas
297,102
472,780
552,573
4.75
1.57
3.15
City of Makati
453,170
471,379
529,039
0.39
1.16
0.78
City of Malabon
280,027
338,855
353,337
1.92
0.42
1.17
City of Mandaluyong
248,143
278,474
328,699
1.16
1.67
1.41
City of Manila
1,601,234
1,581,082
1,652,171
-0.13
0.44
0.16
City of Marikina
310,227
391,170
424,150
2.34
0.81
1.58
City of Muntinlupa
278,411
379,310
459,941
3.14
1.95
2.54
City of Navotas
187,479
230,403
249,131
2.08
0.78
1.43
City of Paranaque
308,236
449,811
588,126
3.85
2.72
3.28
City of Pasig
397,679
505,058
669,773
2.42
2.86
2.64
3
City of San Juan
126,854
117,680
121,430
-0.75
0.31
-0.22
City of Valenzuela
340,227
485,433
575,356
3.62
1.71
2.66
Caloocan City
763,415
1,177,604
1,489,040
4.43
2.37
3.39
Pasay City
368,366
354,908
392,869
-0.37
1.02
0.32
Pateros
51,409
57,407
64,147
1.11
1.12
1.11
Quezon City
1,669,776
2,173,831
2,761,720
2.67
2.42
2.55
Taguig City
266,637
467,375
644,473
5.77
3.26
4.51
2.2. Project Objective
The main objective of this project is to study and design a five-storey building to be constructed with low cost and efficient materials that conform to the standards and specifications on building construction. This includes the day lighting system that can minimize expenses for electricity. An eco-friendly ventilation system will also be added to reduce the cost of energy.
2.3 Design Norms Considered
Efficiency in cost is one of the design norms of the proposal. It should be considered because the main purpose of this project is to reduce the expenses for building construction and decrease energy dependency. Sustainability will be achieved through its collaboration with green engineering. The stability of the structure is one of the important design norms. It should meet the desired standards and specifications in order to be strong and resilient against earthquakes and disasters. Spacing is also a design norm since students need more space to enable them to relax and to promote ease of movement. Spacing is very important in order to allow students to concentrate on their work and activities. This will enable their knowledge to improve and accelerate their effective learning with their teachers.
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2.4 Major and Minor Civil Engineering Fields
The civil engineering areas to be covered are structural, construction and geotechnical engineering. Structural engineering will focus on the superstructures. For construction engineering, it will focus on the materials needed in construction. It will emphasize the mixtures of the materials that can be alternatives source of materials on the making of the cement. Environmental engineering will focus on the design of the energy efficiency of the building. With the combination of natural lighting effects and an ecofriendly ventilation system, this project will help keep nature at an ecological balanced state. 2.5 The Project Beneficiary
Saint Anthony School is the selected beneficiary since the number of student enrollees continues to increase. On the other hand the availability of classrooms is limited. The availability of land to be acquired and on which can be built new facilities is very minimal since nearby areas are already occupied by mixed residential and commercial establishments. The school director decided to choose Saint Francis Building since the current school building consists of only three floors. But the current building needs to be demolished because of the quality and stability conditions of the structure. This will give way to a new and higher structure. With the addition of new facilities such as classrooms and laboratories, the learning activities of the students will continue and the project can be an inspirational model to the other public and private schools. 2.6 Innovative Approach
In this project, the help of different technological developed programs and software was needed to make the project possible and to better improve the design and plan. The following tools were used:
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ETABS This program is an integrated model that computes moment resisting frames, frames with reduced beam sections or side plates, rigid and flexible floors, composite or steel joist floor framing systems, etc.
AutoCAD This program helped in the detailed drawing and laying out of the plan and specifications of the project. This included the architectural and structural plan.
STAADPro This software application program eased the design and analysis of members and checked the adequacy and stability of the structures.
2.7 Research components
The materials that will be used in the construction of the school building will be made of a combination of cement and fly ash for concreting. The materials were examined for a comparative analysis of the cost and quality of low cost materials and conventional materials. The right placing of windows in corridors that maximize air flow was emphasized with the use of metal louvers (used to control the daylight condition for energy savings). Energy efficient methods of air circulation were examined in order to supply fresh air to the building. 2.8 Design components
These were the following:
Substructure It covered the design of foundations, their footing and the adequacy of the load capacity of the structure with the limited settlements of the soil.
Superstructure
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The superstructure will be composed of reinforced concrete beams, columns and slabs. The design depended on such loads as weight, superimposed and seismic. NSCP 2010 and UBC were used.
Roofing design Every member of the truss was planned and analyzed because of the factors that may affect the condition of the roofs. Wind loads, dead loads and roof live loads were consequently designed with precision and accuracy.
2.9 Sustainable Development
As the number of school children continues to increase, more facilities such as classrooms are also needed. Building structures incorporated with low cost materials such as combining alternative materials will pave the way for the encouragement of different learning institutions. The reduced expenses of the proposed project will help since alternative materials will be applied instead of conventional materials which cost more. Naturally ventilated buildings feel more comfortable than ones that are air conditioned. But the site of the building, with factors such as topography and the proximity of other buildings and main roads, may well prevent this from being feasible.
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Chapter 3
Environmental Environmental Examination Report 3.1 Project Description
3.1.1 Project Rationale
San Andres is a district located in the south east of the City of Manila. Although it only has a small land area, it is the second most densely populated district in Manila after Tondo. The district is home to two private schools, St. Scholastica's College and St. Anthony School. In order to alleviate overcrowding and accommodate the growing school population, it was proposed to study the design and construction of a five-storey school building at St. Anthony School that is both an eco-friendly sustainable structure and structurally stable. The aim of this project is to provide a place for comprehensive education that will support each individual in society to achieve their potential as a human being. It will also equip the students with the skills to maintain a healthy and productive existence, to grow into resourceful and socially active adults, and to make cultural and political contributions to their communities.
3.1.2 Project Location
St. Anthony School at San Andres, Manila is the chosen site since the school needs improvement in the upgrading the facilities due to its old structural stability and to accommodate more students and teachers. (See tables 2.1 & 2.2.)
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3.1.3 Project Information
The project is a design of a five-storey school building and will be located in Singalong St., St Anthony School, San Andres, Manila. It will be an eco-structure because it will be made of sustainable low cost materials. It will be one of the most economical designs and be made of cheap and alternative materials that will be funded by the private school. Air ventilation along corridors will be built according to the plan.
Figure 3.0 The vicinity map of Saint Francis Building
Saint Francis Building
Figure3.1 Map view of the location of the Proposed Project
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3.1.4 Description of Project Phases
The project will have four phases: pre-construction/operational, construction phase, operational and abandonment. The pre-construction/operational phase includes the things to be done before the t he project starts; it is the preparation before the construction and operational phases. The construction phase includes the preparation of the site and construction of the structure. The operational phase of the project discusses how it operates or works. And lastly the abandonment phase discusses what should be done with the project if it is unoccupied.
3.1.5 Pre-construction/Operation phase
3.1.5.1 Preparation of Construction Documents
Construction documents are part of the legal contract between the property owner and general contractor.
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3.1.5.2 Design review and commentary
To identify design conflicts as part of a pre -construction constructability review.
3.1.5.3 Construction phasing, sequencing and site logistics
Construction planning includes site investigation, site management, obtaining permits, scheduling, excavation planning, estimating, value engineering and quality control.
3.1.6 Construction phase
3.1.6.1 Clearing and Grubbing
Clearing and grubbing consists of removing all objectionable materials from within the work site.
3.1.6.2 Excavation
Excavation of soil by cut and fill is needed in order to place the sub-structure or the foundation itself.
3.1.6.3 Building Structure
This consists of the construction of the footing, beams, slabs, columns and walls.
3.1.6.4 Water and Sewer Lines
This is the construction of pipe lines for water supply and sewer drainage lines.
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3.1.7 Operational Phase
3.1.7.1 Framing
Framing is a building technique based around structural members, usually called studs, which provides a stable frame to which interior and exterior wall coverings are attached.
3.1.7.2 Insulation and Sheetrock
Insulation and Sheetrock is done after framing and mechanical inspections are finished. After insulation and sheetrock taping, be dding and texturing of the interior walls can be started.
3.1.7.3 Flatworks
Flatworks can be done simultaneously while the structure is nearly in completion. Flatworks include any patios, all sidewalks and driveways.
3.1.8 Abandonment Phase
3.1.8.1 Removal of Waste
During construction, demolition and land clearing debris results from construction activities; these materials can be recycled, reused or salvaged. The proper disposal of waste is necessary.
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3.1.8.2 Dismantling of Structures and Equipment
After the dismantling of equipment and structures, restoration plans are to be put out, some of these are re-vegetation, leveling and backfilling, and the repair of road networks.
3.2 Description of Environmental Setting and Receiving Environment
3.2.1 Physical Environment
The location of the proposed project is surrounded mostly by residential structures and some commercial establishments and also it is accessible due to the nearby roadways. The area of the project location has minimal space therefore a small portion of the quadrangle inside the school is enough to re-construct a five-storey school building. The size of the lot is 680.93 square meters. The project will maximize the size of the available area by adding new rooms, laboratories and an auditorium.
3.2.2 Biological Environment
Within the area, there is a garden beside the existing building. Vegetation living in the vicinity is absent because of unplanned zoning. Different establishments have sprouted in the area. Roads and pathwaysare made up of concrete and only a few trees are present which means animal and plant life are not concerns to address. The atmospheric condition in the area is impaired due to the pollution produced by the vehicles in the roads near the site.
3.2.3 Socio- Cultural, Economic and Political Environment
In the social aspect, a school is going to be built, wherein lively relationships between individuals may therefore be formed and , likewise, the said institution covering primary and secondary education can therefore instill the Filipino value of giving high
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importance to education. In the economic aspect, by applying modern techniques like the use of natural day lighting and constructing well ventilated facilities, expenses for energy can be reduced in the near future. In addition, the project will promote employment within the area and those who live near the area. Other than that, additional facilities like classrooms, laboratories, and an auditorium will help the quality of education of the said institution.
3.2.4 Future Environmental Conditions without the Project
There would be no significant change in the environmental condition with/without the construction of the proposed project; in climate, atmosphere, etc. since there is a small amount of plants within the location, with the construction of the project there would be a minimal impact on the environment due to replacing the existing three-storey school building.
3.3 Impact Assessment and Mitigation
3.3.1 Summary Matrix of Predicted Environmental Issues/Impacts and their Level of Significance at Various Stages of Development
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Table 3.1 Summary Matrix of Predicted Environmental Issues/Impacts and their Level of
Significance at Various Stages of Development
Predicted Environmental Issues/Impacts
Level of Significance
Water Quality
Low Impact
Air Quality
Low Impact
Noise Pollution
Low Impact
Waste Generation
Moderate Impact
Population Density
High Impact
3.3.2 Brief Discussion of Specific Significant Impacts on Physical and Biological Resources
3.3.2.1 Existing Land Uses
The proposed site for constructing a new building is a three-storey existing building that will be demolished first before a new one can be built.
3.3.2.2Atmospheric Condition
The atmospheric condition in the area is not at its best condition. The quality of the present atmospheric condition has been impaired because the site is situated near the main roads of San Andres, Manila.
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3.3.3 Brief Discussion of Significant Socio-economic Effects/Impacts of the Project
Since the major purpose of this project is to accommodate more students in St. Anthony School, it will greatly improve the education occurrence of the residents of San Andres Manila by adding more facilities such as laboratories and an auditorium to the proposed project.
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3.4 Environmental Management Plan
3.4.1 Summary Matrix of Proposed Mitigation and Enhancement Measures, Estimated Cost and Responsibilities
Table 3.2Summary Matrix of Proposed Mitigation and Enhancement Measures,
Estimated Cost and Responsibilities
Impact
Mitigation
Responsibilities
• Proper surface and ground drainage, Water Quality
• Conservation of water during construction
Contractor
phase to ensure efficient water use.
• Site and stock pile enclosure (sand stockpiles and tiles boxes were enclosed once on-site);
• On-site mixing in enclosed or shielded areas (Mixing of small quantities of materials was done in the open air near the respective works);
• Proper unloading operations (piled Air Quality
curbstone and sand piles, no recorded accidents), manual transport of materials onsite, no heavy trucks were allowed to enter into the construction area;
• Keeping hauling routes free of dust and regularly cleaned through water spraying after each activity;
• Construction safety nets were used to prevent dust from reaching and affecting
Contractor
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pedestrians;
• Water was frequently sprayed to reduce dust dispersion.
• Surface water and groundwater are not expected to be affected by the project activities since the paint used is water-based Water Quality
(as an alternative to petroleum solvents);
Contractor
• Oil and lubricants from vehicles and machinery are considered negligible since the on-site use of machinery is not significant.
• limiting the noisiest construction activities to daytime hours to the greatest extent possible Noise Pollution
• building permanent noise barriers during the
Contractor
early phases of construction (where construction sequencing allows) in order to reduce noise levels.
• Waste transport and disposal at designated disposal sites (integrated solid waste Waste Generation
management).
• Construction wastes are collected in isolated
Contractor
areas and disposed of according to declared collection schedules. Population Density
• Use of construction safety nets for public safety.
Contractor
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3.4.2 Brief Discussion of Mitigation and Enhancement Measures
3.4.2.1 Mitigation Measures for the Project Design 3.4.2.1.1 Dust Production
To prevent dust along roadways, circulation and access roads used by the collection trucks should be paved. To prevent dust from the unloading of wastes in the facility, a high quality paving capable of withstanding frequent truck traffic should be used to cover the receiving area.
3.4.2.1.2 Public Hazards
Proper fencing at a minimal height of three meters around the whole site should be ensured in order to prevent unauthorized access to the facility.
3.4.2.2 Mitigation Measures for the Construction Phase
During the construction phase, it is essential to adopt strategies to prevent or minimize dust emissions, noise generation, health and safety hazards, and negative impacts related to the generated construction wastes. The main control measures should be included within the construction contracts and be considered as requirements from contractors.
3.4.2.2.1 Noise and Dust Emissions
The major mitigation measures required to reduce noise and dust emissions are mainly during the construction phase. The recommended mitigation measures for dust emissions are on-site mixing and unloading operations, and ensuring adequate maintenance and repair of construction machinery.
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3.4.2.2.2 Construction Wastes
All waste resulting from construction works, land reclamation, or any other activity should be collected and disposed of appropriately such as in a sanitary landfill or an alternative government-permitted disposal site. Uncontrolled littering in the facility and surrounding areas should be prevented.
3.4.2.2.3 Health and Safety Hazards
To prevent accidents, members of the public should not be allowed to access the construction site at any time, especially after working hours. This is ensured by proper site closure, fencing, and securing the site using a night guard. In case of visits by local monitoring teams, the teams should respect the safety codes set by the site management and should be accompanied by the responsible personnel.
3.4.2.3 Mitigation Measures for the Operation Phase
3.4.2.3.1 Noise Pollution
To reduce objectionable noises, the collection and transport of wastes to the facility should be performed at times not to create traffic, nor to disturb the public during hours of sleep. Noise from the plant should not reach objectionable levels, and working hours (7:00 am to 6 pm) should not be exceeded. The various incoming trucks to the location should be equipped with proper mufflers to reduce noise.
3.4.3 Monitoring Plan
In the process of construction a person will be assigned to make sure that each and every mitigation and enhancement measure included will then be followed. The monitoring must be strictly followed to ensure safety.
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Table3.3 Monitoring Plan
Impact
Measure
Monitoring
Air Quality
Masks
Daily
Noise Pollution
Noise Control
Weekly
Waste Generation
Check of waste
Daily
Population
Crowd control
Daily
3.4.4 Contingency Plan
In the duration of the construction, the construction area, just like any other construction project, will have a safety area that will have every first aid material that may be needed and someone who knows how to perform first aid. Also in the duration of project construction and even after construction, there should be assured safety by having emergency measures and equipment like fire extinguishers and alarms.
3.4.5 Institutional Responsibilities and Agreements
To be built is an environment-friendly structure that will serve as a school that will offer primary education. For the proponent’s institutional responsibilities and agreements, it was agreed to make it a point to consider the environmental effects of this project as well as the structural codes to be followed and to therefore comply with the requirements of the local government in the case of building an establishment in the vicinity.
It was made a point to coordinate with the local government, DENR
(Department of Environment and National Resources) and DEPED (Department of Education) to have guidelines to follow and to be monitored for the betterment of both the owner of the project and the people that surround the area.
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Chapter 4
4. Research Component 4.1 Introduction
A large number of innovative alternative building materials and low cost construction techniques have been developed through intensive research efforts during the last three to four decades that satisfy functional as well as specification requirements of conventional materials/techniques and that provide ways of bringing down construction costs. Fly ash, an industrial by-product from thermal power plants with a current annual generation of approximately 108 million tones and with proven suitability for a variety of applications as admixture in cement/concrete/mortar, lime pozzolana mixture (bricks/blocks) etc., is such an ideal material that attracts a lot of attention. Fly ash utilization in building materials has many advantages, like cost effectiveness, being environmental friendly, increases in strength, and the conservation of other natural resources and materials.
Fly ash or pulverized fuel ash, an artificial pozzolana, is the residue from the combustion of pulverized coal used as fuel. During the combustion of coal, the products formed are classified into two categories, viz. bottom ash and fly ash. The bottom ash is that part of the residue which is fused into particles. Fly ash is that part of the ash which is entrained in the combustion gas leaving the boiler. Most of this fly ash is collected in either mechanical collectors or electrostatic precipitators.
Fly ash is disposed of either by dry or wet systems. Most power plants in India use the wet disposal system. Different types of coal produce different quantities of ash, depending on the concentration of mineral matter in the respective types of coal. In India the coal contains a very high percentage of rock and soil and therefore the ash contents are as high as 50%.
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Ash may be classified into two groups as Class C and Class F, based on the nature of their ash constituents. One is bituminous ash (Class F) and the other is the lignite ash (Class C). Lignite ashes contain more calcium oxide and magnesium oxide than ferric oxide, but bituminous ash contains more ferric oxide than calcium and magnesium oxides. The average particle size of lignite fly ash is considerably coarser than the bituminous variety. Also free lime is present in all the lignite fly ashes. The lignite ash (Class C) in India is produced at Neyveli Thermal Power Plant and the most of the other power plants in India produce bituminous ashes (Class F).
4.2 Review of Related Literature
4.2.1 Fly Ash
Fly ash is a byproduct of coal burning power plants and is classified as pozzolan. The particles of fly ash are spherical in shape, generally finer than cement. Fly ash in bulk is very similar to cement in its appearance and its physical and chemical properties (ASCC & ACI).
When used in cement in concrete mix, fly ash reacts with calcium hydroxide, a chemical by product of cement hydration, producing the same binder as Portland cement.
Through this “pozzolanic” reaction, fly ash is a part of the total cementitous material. When fly ash is used in concrete it is usually replace part of the Portland cement content. Because reactions vary, the mix must be proportioned specifically for the cement and fly ash being used (ASCC & ACI).
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4.2.2High-Volume Fly Ash Concrete
Fly ash, a principal by-product of coal-fired power plants, is well accepted as a pozzolanic material that may be used either as a component of blended Portland cements or as a mineral admixture in concrete. In commercial practice, the dosage of fly ash is limited to 15%-20% by mass of the total cementitious material. Usually, this amount has a beneficial effect on the workability and cost economy of concrete but it may not be enough to sufficiently improve the durability to sulfate attack, alkali-silica expansion, and thermal cracking. For this purpose, larger amounts of fly ash, on the order of 25%-35% are being used.
Although 25%-35% fly ash by mass of the cementitious material is considerably higher than 15%-20%, this is not high enough to classify the mixtures as High Volume Fly Ash (HVFA) concrete according to the definition proposed by Malhotra and Mehta. From theoretical considerations and practical experience it has been determined that, with 50% or more cement replacement by fly ash, it is possible to produce sustainable, high performance concrete mixtures that show high workability, high ultimate strength, and high durability.
4.2.3High Performance Concrete
The characteristics defining an HVFA concrete mix ture are as follows:
•
A minimum of 50% of fly ash by mass of the cementitious materials must be maintained.
•
Low water content, generally less than 130 k g/m,3 is mandatory.
•
Cement content of generally no more than 200kg/m3 is desirable.
•
For concrete mixtures with specified 28-day compressive strength of 30 MPa or higher, slumps >150 mm, and water-to-cementitious materials ratio of the order of
24
0.30, the use of high-range water-reducing admixtures (superplasticizers) is mandatory.
•
For concrete exposed to freezing and thawing environments, the use of an airentraining admixture resulting in adequate air-void spacing factor is mandatory.
•
For concrete mixtures with slumps less than 150 mm and 28-day compressive strength of less than 30 MPa, HVFA concrete mixtures with a water-tocementitious materials ratio of the order of 0.40 may be used without superplasticizers.
4.2.4 Characteristics of Fly Ash
Fly ash is a diverse substance. The characteristics of fly ash differ depending on the source of the coal used in the power plant and the method of combustion. Cenospheres, hollow spherical particles as part of fly ash, are believed to be formed by the expansion of C02 and H20 gas, and evolved from minerals within the coal being burnt. The predominant forces are, however, the pressure and surface tension on the melts, as well as gravity. The predominantly spherical microscopic structure of fine fly ash is related to the equilibrium of the forces on the molten inorganic particle as it is forced up the furnace or smoke stack against gravity. The molten inorganic particles cool down rapidly, maintaining their equilibrium shape. A similar situation is found in spherical drops of water falling from a faucet. Because cenospheres are hollow, they have a low bulk density. The percentage of cenospheres increases with the ash content in the coal, and decreases with the concentration of Fe203. This indicates that Fe2C>3 is concentrated in the higher density 3
fraction of fly ash, which is to be expected from the high density of Fe203 (5.25 g/cm ) 3
and Fe304 (5.17 g/cm ). The iron species should not contribute significantly to the infrared spectra.
The inorganic material is entrained over years in the coal melt during the combustion of coal in the furnace, and with some, but limited, fusing of the molten particles. Some of the vaporized low boiling elements, for example alkali metal salts,
25
coalesce to form submicron particles. Some of the vaporized compounds, most notably the polynuclear aromatic hydrocarbons and polycyclic aromatic hydrocarbons, adsorb onto the surface of the fly ash particles. The surface of fly ash particles is, therefore, commonly enriched in carbon, potassium, sodium, calcium and magnesium
4.2.5 Advantages and Disadvantages of Fly Ash
4.2.5.1 Advantages
Fly ash improves concrete workability and lowers water demand. Fly ash particles are mostly spherical tiny glass beads. Ground materials such as Portland cement are solid angular particles. Fly ash particles provide a greater workability of the powder portion of the concrete mixture which results in greater workability of the concrete and a lowering of water requirement for the same concrete consistency. Pum p ability is greatly enhanced.
1. Low water/cement ratio 2. Low permeability 3. Resistance to sulfate 4. Minimization of alkali-silica reaction 5. Minimum segregation 6. Decreasing in heat of hydration 7. İncreasing the strength 8. Smooth concrete surface 9. Perfect concrete rheology 10. Environment-friendly
Fig. 3.1 Compressive Strength of Fly Ash Concrete and Conventional Concrete
26
Source: A Ground Breaking Presentation to the Management Association of The Philippines by EJ Fransman of SAPTASCO- Septeber 2009
4.2.5.2 Disadvantages
1. Slower strength gain 2. Longer setting times 3. Air content control 4. Seasonal limitations 5. Color variability
The structural effects of fly ash may be more critical, but cosmetic concerns also affect its use in concrete. It is more difficult to control the color of concrete containing fly ash than mixtures with Portland cement only. Fly ash also may cause visual inconsistencies in the finished surface, such as dark streaks from carbon particles.
27
4.2.6 Mechanisms by which fly ash improves the properties of concrete
A good understanding of the mechanisms by which fly ash improves the rheological properties of fresh concrete and ultimate strength as well as the durability of hardened concrete is helpful to insure that potential benefits expected from HVFA concrete mixtures are fully realized. These mechanisms are discussed next.
4.2.6.1 Fly ash as a water reducer
Too much mixing-water is probably the most important cause for many problems that are encountered with concrete mixtures. There are two reasons why typical concrete mixtures contain too much mixing-water. Firstly, the water demand and workability are influenced greatly by particle size distribution, particle packing effect, and voids present in the solid system. Typical concrete mixtures do not have an optimum particle size distribution, and this accounts for the undesirably high water requirement to achieve certain workability. Secondly, to plasticize a cement paste for achieving a satisfactory consistency, much larger amounts of water than necessary for the hydration of cement have to be used because Portland cement particles, due to the presence of an electric charge on the surface, tend to form flocs that trap volumes of the mixing water.
It is generally observed that a partial substitution of Portland cement by fly ash in a mortar or concrete mixture reduces the water requirement for obtaining a given consistency. Experimental studies by Owen and Jiang and Malhotra have shown that with HVFA concrete mixtures, depending on the quality of fly ash and the amount of cement replaced, up to a 20% reduction in water requirements can be achieved. This means that good fly ash can act as a superplasticizing admixture when used in high-volume. The phenomenon is attributable to three mechanisms. First, fine particles of fly ash get absorbed on the oppositely charged surfaces of cement particles and prevent them from flocculation. The cement particles are thus effectively dispersed and will trap large amounts of water, which means that the system will have a reduced water requirement to achieve a given consistency. Secondly, the spherical shape and the smooth surface of fly
28
ash particles help to reduce inter-particle friction and thus facilitate mobility. Thirdly, the
“particle packing effect” is also responsible for the reduced water demand in plasticizing the system. It may be noted that both Portland cement and fly ash contribute particles that are mostly in the 1 to 45 µm size range, and therefore serve as excellent fillers for the void space within the aggregate mixture. In fact, due to its lower density and higher volume per unit mass, fly ash is a more efficient void-filler than Portland cement.
4.2.6.2 Drying shrinkage
Perhaps the greatest disadvantage associated with the use of Portland-cement concrete is cracking due to drying shrinkage. The drying shrinkage of concrete is directly influenced by the amount and the quality of the cement paste present. It increases with an increase in the cement paste-to-aggregate ratio in the concrete mixture, and also increases with the water content of the paste.
Clearly, the water-reducing property of fly ash can be advantageously used for achieving a considerable reduction in the drying shrinkage of concrete mixtures.
The significance of this concept is illustrated by the data in Table 2 which shows mixture proportions of a conventional 25 MPa concrete compared to a superplasticized HVFA concrete with similar strength but higher slump. Due to a significant reduction in the water requirement, the total volume of the cement paste in the HVFA concrete is only 25% as compared to 29.6% for the conventional Portland-cement concrete which represents a 30% reduction in the cement paste-to-aggregate volume ratio.
29
Table 2 Comparison of cement paste volumes
Conventional concrete
HVFA concrete
kg/m
m
kg/m
m
Cement
307
0.098
154
0.149
Fly ash
-
-
154
0.065
Water
178
0.178
120
0.120
Entrapped air (2%)
-
0.020
-
0.020
Coarse aggregate
1040
0.385
1210
0.448
Fine aggregate
825
0.305
775
0.287
Total
2350
0.986
2413
0.989
w/cm
0.58
-
0.39
-
Paste: volume
-
0.296
-
0.254
Percent
-
30.0%
-
25.7%
4.2.6.3 Thermal cracking
Thermal cracking is a serious concern in massive concrete structures. It is generally assumed that this is not a problem with reinforced-concrete structures of moderate thickness, e.g. 50-cm thick or less. However, due to the high reactivity of modem cements, cases of thermal cracking are reported even from moderate-size structures made with concrete mixtures of high-cement content that tend to develop excessive heat during curing. The physical-chemical characteristics of ordinary Portland cements today are such that very high heat-of-hydration is produced at an early age compared with that of normal Portland cements available 40 years ago. Also, high-early strength requirements in modem construction practice are usually satisfied by an increase in the cement content of the concrete mixture. Further, there is considerable construction activity now in the hot-arid areas of the world where concrete temperatures in excess of 60°C arc not uncommon within a few days of concrete placement.
For unreinforced mass-concrete construction, several methods are employed to prevent thermal cracking, and some of these techniques can be successfully used for the
30
mitigation of thermal cracks in massive reinforced-concrete structures. For instance, a 401
MPa concrete mixture containing 350 kg/m Portland cement can raise the temperature of concrete by approximately 55-60°C within a week if there is no heat loss to the environment. However, with a HVFA concrete mixture containing 50% cement replacement with a Class F fly ash, the adiabatic temperature rise is expected to be 3035°C. As a rule of thumb, the maximum temperature difference between the interior and exterior concrete should not exceed 25"C to avoid thermal cracking. This is because higher temperature differentials are accomplished by rapid cooling rates that usually result in cracking. Evidently, in the case of conventional concrete it is easier to solve the problem cither by keeping the concrete insulated and warm for a longer time in the forms until the temperature differential drops below 25°C or by reducing the proportion of Portland cement in the binder by a considerable amount. The latter option can be exercised if the structural designer is willing to accept a slightly slower rate of strength development during the first 28 days, and the concrete strength specification is based on 90-days instead of 28-day strength.
4.2.6.4 Water-tightness and durability
In general, the resistance of a reinforced-concrete structure to corrosion, alkaliaggregate expansion, sulfate and other forms of chemical attacks depends on the watertightness of the concrete. The water-tightness is greatly influenced by the amount of mixing-water, type and amount of supplementary cementing materials, curing, and cracking resistance of concrete. High-volume fly ash concrete mixtures, when properly cured, are able to provide excellent water-tightness and durability. The mechanisms responsible for this phenomenon arc discussed briefly below.
When a concrete mixture is consolidated after placement, along with entrapped air, a part of the mixing-water is also released. As water has low density, it tends to travel to the surface of concrete. However, not all of this "bleed water" is able to find its way to the surface. Due to the wall effect of coarse aggregate particles, some of it accumulates in the vicinity of aggregate surfaces, causing a heterogeneous distribution of water in the
31
system. Obviously, the interfacial transition zone between the aggregate and cement paste is the area with high water/cement and therefore has more available space that permits the formation of a highly porous hydration product containing large crystals of calcium hydroxide and ettringite. Micro cracks due to stress are readily formed through this product because it is much weaker than the bulk cement paste with a lower water/cement.
It has been suggested that micro cracks in the interfacial transition zone play an important part in determining not only the mechanical properties but also the permeability and durability of concrete exposed to severe environmental conditions. This is because the rate of fluid transport in concrete is much larger by percolation through an interconnected network of micro cracks than by diffusion or capillary suction. The heterogeneities in the micro cracks of the hydrated Portland-cement paste, especially the existence of large pores and large crystalline products in the transition zone, are greatly reduced by the introduction of fine particles of fly ash. With the progress of the pozzolanic reaction, a gradual decrease occurs in both the size of the capillary pores and the crystalline hydration products in the transition zone, thereby reducing its thickness and eliminating the weak link in the concrete microstructure. In conclusion, a combination of particle packing effect, low water content, and pozzolanic reaction accounts for the eventual disappearance of the interfacial transition zone in HVFA concrete, and thus enables the development of a highly crack-resistant and durable product.
4.2.7 Carbon Content of Fly Ash
It has been reported that concrete containing fly ash can be durable to the effects of freezing and thawing provided it has a stable air-void system. There have been reports of carbon content in the fly ash reducing the effectiveness of air-entraining agent. Sturrup, Hooton and Clendennning (1983) found that doubling the carbon content required a double dosage of air-entraining admixture for entraining about 6.5 ± 1 % air. They mentioned in their findings that as long as the required air contents are obtained,
32
carbon content in the fly ash does not adversely affect the performance of fly ash concrete vis-a-viz the effects of freezing and thawing.
4.3 Methodology
In order to come up with the design of the project, necessary data were gathered from the population statistics and economic activity of San And res, Manila, as well as the population density of students needed by the school, up to the soil properties of the proposed school. After obtaining the necessary information needed for the project, a five-storey school that can accommodate students of San Andres, Manila was designed. As the number of students continues to rise, more and m ore school facilities such as classrooms are needed by the school. As the materials are known for the design of the project, initial cost estimation was done in order to know that the funds can be raised by the school institution. Since the objective of the proposal is to reduce the cost of the materials used in the design of the project, the school can afford and utilize them properly.
33
START
Data Gathering (population of students on the location)
Develop Draft Plan
Consultation of Draft Plan
Design Process
Estimation of the Project
END
Figure 1.0 Flow Chart of Project
34
Chapter 5
Detailed Engineering Design
Design was conducted according to National Structural Code of the Philippines 2010 Vol. 1. The Ultimate Strength Design approach was used as a design criterion. All load combinations were entered into the model, and the combined load effects were compared to the reduced nominal strengths of the members. In addition to analyzing members under typical load effects, for seismic design, a drift criterion accounting for plastic deformation was enforced.
The structure was designed for serviceability: Deflections of beams under service live load are limited to L/240 and story drifts under 50-year wind events (unfactored wind load) are limited to L/400. A computer model was constructed in ETABS to conduct three-dimensional frame analysis of the structure. The model included only the main beams and the columns; the floor beams and decking were designed by hand. Lateral loads were applied to diaphragms at each floor; diaphragms were assumed rigid as justified by a diaphragm flexibility study.
Dead, live, roof live and snow loads were calculated in accordance with NSCP 2010. Rain loads were assumed to be negligible compared to the roof live load. Calculations of gravity loads are included. Dead loads were calculated, including the weight of all structural components (columns, main beams, floor beams, and floor system), cladding, and a superimposed dead load of 25 psf on the roof and 15 psf on all floors.
The LRFD load combinations were used to find maximum compression, tension, shear force and bending moment in all members. This strength requirement governed member selection of non-moment frame columns and braces. In these cases, the lightest members were chosen to resist loads in critical members, and member sections were
35
repeated if reasonable. In all other cases, either story drifts or serviceability requirements governed member selection. Serviceability A beam deflection criterion of L/240 was used under service live load for all beams. For all simply-supported beams in the structure, this deflection limitation controlled the selection. The service wind story drift limitation of L/400 was met and did not control for any members. This is because the lateral force-resisting system was already very stiff to handle seismic loads.
According to NSCP 2010 Section 410, analysis included here the investigation of reinforced concrete beams subject to steel yielding, and decision if it is to be designed as non-rectangular or rectangular, singly-reinforced or doubly-reinforced concrete beams. Included here are the determination of strength reduction factor and the steel ratio. Also included were the axial capacity analysis of columns and the design of ties and vertical bars.
According to NSCP 2010 Section 411, analysis included here the determination of size of stirrups and their spacing, and also the investigation if the reinforced concrete has the capacity to resist shearing forces. Code provisions for design ranges from a simplified design to a much detailed design when given axial, flexure and shear reaction altogether. According to NSCP 2010 Section 413, analysis included here the stress spread, and the design and spacing of steel bars in a two way slab. It facilitates on how the bars would be placed along the slab using the direct design method. Code provisions set also the maximum bending moments at each faces of the members. According to NSCP 2010Section 415, analysis of concrete footings included the investigation of concrete footings under one-way and punching shear failure, and how the reinforcing bars would be laid out in both directions of the footing. It has a provision on the minimum thickness of footings and the location of the critical section for both oneway and punching shear.
36
Estimation and budget schedule are based on the technical data coming from a professional Quantity Surveyor and/or Cost Engineer. The project schedule is prepared and outlined using Microsoft Project containing all the significant and critical project activities. Also included here are geotechnical profiles and field results of our project, such as borehole results, soil consistence, cohesion and unit weight of the soil profile.
To facilitate the output of our project more accurately, the structural design specifications shall be shown, like the beam, column, footing and slab schedule, at which is presented the exact details like the number and size of top and bottom bars, the concrete beam dimensions, and the effective depth of the structural members, per every level and unit of our project. Preliminary data for design loads that served bases for our structural design shall also be included, like the dead, live, superimposed, wind and other essential loads of our project provided by NSCP 2010.
37
5.1 Loads and Codes
5.1.1 Introduction
The structural design of the five-storey hospital structure conforms to the National Structural Code of the Philippines 2010 for Volume 1: For Buildings and other Vertical Structures and to the American Concrete Institute Code for Buildings. All values used in the design are found in NSCP 2010: Minimum Design Loads. Seismic considerations are in reference according to Uniform Building Code 1997.
5.1.2 Codes
SECTION 103: CLASSIFICATION OF STRUCTURE:
Nature of Occupancy: I Essential Facilities Public School Buildings
SECTION 104: DESIGN REQUIREMENTS:
104.1 Strength Requirement: Strength capacity of the school building 104.2 Serviceability Requirement: Stiff and durable 104.3 Analysis: Load and resistance factor design 104.4 Foundation investigation 104.5 Design Review: Engr. Divina Gonzales SECTION 105: POSTING AND INSTRUMENTATION
SECTION 106: SPECIFICATIONS, DRAWINGS, AND CALCULATIONS
SECTION 108: EXISTING STRUCTURES:
38
5.1.3 Dead Loads
All Floors
Dead Load
Load
Unit
Mechanical Duct Allowance
0.2
kPa
Plaster on Concrete
0.24
kPa
Elec. & Plumb Allowance
0.1
kPa
Acoustical Fiber Board
0.05
kPa
Cement Finish (25mm)
1.53
kPa
Ceramic or Quarry Tile (20mm)
1.10
kPa
1
kPa
4.22
kPa
Ceiling:
Floor Finishes
Partitions:
Concrete Hollow Blocks Total Dead Load 5.1.4Live Loads
First Floor Live Load
Load
Unit
Classrooms
1.9
kPa
Corridors above ground floor
4.8
kPa
Restrooms
2.4
kPa
Ground Floor corridors
4.8
kPa
Exit Facilities
4.8
kpa
Total
18.7
kPa
39
Second Floor Live Loads
Loads
Unit
Classrooms
1.9
kPa
Corridors above ground floor
4.8
kPa
Restrooms
2.4
kPa
Ground Floor corridors
4.8
kPa
Exit Facilities
4.8
kpa
Total
18.7
kPa
Live Loads
Load
Unit
Classrooms
1.9
kPa
Corridors above ground floor
4.8
kPa
Restrooms
2.4
kPa
Ground Floor corridors
4.8
kPa
Exit Facilities
4.8
kpa
Total
18.7
kPa
Live Loads
Load
Unit
Classrooms
1.9
kPa
Corridors above ground floor
4.8
kPa
Restrooms
2.4
kPa
Ground Floor corridors
4.8
kPa
Exit Facilities
4.8
kpa
Total
18.7
kPa
Third Floor
Fourth Floor
40
Fifth Floor Live Loads
Loads
Unit
Classrooms
1.9
kPa
Corridors above ground floor
4.8
kPa
Restrooms
2.4
kPa
Ground Floor corridors
4.8
kPa
Exit Facilities
4.8
kpa
Total
18.7
kPa
Sixth Floor/ Roof Deck
Load
Unit
Catwalk
1.9
kPa
Basic Floor Areas
1.9
kPa
Exit Facilities
4.8
kPa
Total
8.6
kPa
Live Loads
Total Live Load =
18.7 (First Floor) +18.7(Second Floor) +18.7(Third Floor)
Total Live Load =
+18.7(Fourth Floor) +30.7(Fifth Floor) +8.6(Roofdeck) Total Live Load
=
114.1 kPa
41
5.1.5Earthquake Loads
Design Considerations
Ct = 0.0731 (Concrete) Overstrength Factor, R = 3.5 (ordinary concrete frame) Soil Profile Type = SD Zone no. = 4 Seismic Zone Factor, Z = 0.4 Ca = 0.44Na = 0.44 Cv = 0.64Nv = 0.768 Seismic Source Type = A Na = 1.00 Nv = 1.2 Occupancy Category = I Importance Factor I = 1.5 (Essential Facilities) Valley Fault System
5.1.6 Wind Load
Design Considerations
The design shall conform to the NSCP Zone Classification Basic Wind Speed:
Manila Area (Zone 4): V = 200 kph = 125 mph Iw = 1.15 Exposure, B
42
5.1.6 Load Combinations
U = 1.4D U = 1.2D + 1.6L U = 0.9D + 1.4E U = 1.0D + 1.0W U = 1.0D + 0.12E
Where: D = dead load L = live load W = wind load E = load effects of earthquake
43
5.2 Structural Design
5.2.1 Introduction
Using application software such as STAAD and ETABS, the design of the proposed school building will be utilized precisely and effectively. STAAD was used for the two trusses that will cover the open spaced of the structure. ETABS designed the whole super structure since the roof deck is made of reinforced concrete. Lastly, the application software SAFE concentrated on the design of the foundation of the structure. SAFE is an application that focuses on the design of the foundation; the data processed in ETABS can be transferred through this program.
5.2.2 Beam Design
Using ETABS, the design and analysis of beams was computed.
***See Appendix
5.2.3 Column Design
Using ETABS, the design and analysis of columns was computed.
***See Appendix
5.2.4 Slab Design
Using ETABS, the design and analysis of slab was computed.
5.2.4.1 One Way Slab
***See Appendix
44
5.2.4.2 Two Way Slab
***See Appendix
5.2.5 Design of Truss
The design of the truss in the structure to be considered is the open space found in corridors of the school building. In order to preve nt an overflow of water during typhoons the materials used in the truss analysis are made of Howe Truss. The roof in the truss is made of polycarbonate sheets.
5.2.5.1 Design Consideration
2
Polycarbonate Sheet (w = 4.0 kg/m ) Polycarbonate Sheet Thickness, 4.5mm Roof Live Load , RLL = 0.6 kPa Dead Load ,DL = 0.096 kPa Wind Load , WL = 0.6109 kPa θ=
23.50°
f y = 170 MPa Bay Distance , L = 3 m
45
C 3 x 4.1
Weight, w (kg/m)
6.14
2
Area, A (mm )
781
Section Modulus about X, 3
18.14
3
Sx(x 10 mm )
Section Modulus about Y, 3
3.36
3
Sy(x 10 mm ) Ref er ence :
Orientation
Association of Structural Engineers of the Philippines (ASEP) Steel Manual
C 3 x 4.1: 3
Sx = 18.14 mm 3
Sy = 3.36 mm
W t = RLL + DL + WL W t = 0.6 + 0.096 + 0.6109 W t = 1.3069 KPa
WT
Load along x-axis: Wx = Wt cos θ Wx = 1.3069 cos 23.5 Wx = 1198.5189 N/m
Load along x-axis: Wy = Wt sin θ Wy = 1.3069 sin 23.5 Wy = 521.0952 N/m
o
23.5
46
Actual stress along x-axis:
MPa
Actual stress along y-axis:
MPa
Allowable stress along x-axis:
MPa
Allowable stress along y-axis:
MP
47
Checking for Adequacy:
Since 0.964 falls under 0.9 to 1.0, then the section of the purlins is adequate and economical .
Top Chords, Bottom Chords and Web Members
The Section & Its Properties
Orientation L 20 x 20 x 3
Weight, w (kg/m)
0.88
Area, A (mm )
112
Radius of Gyration about X, rx(mm)
Radius of Gyration about Y, ry(mm)
5.9
5.9
48
5.2.5.2 Design of Howe Truss
STAAD Model
3D Model
49
STAAD Output Table 5.3Support Reactions End Forces
JOINT
8
12
LOAD
FORCE-
FORCE-
FORCE-
MOM-X
MOM-Y
MOM Z
X
Y
Z
1
0.00
8 .99
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
1
-25.17
1.95
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
STAAD Output Table 5.4 Member End Forces
MEMBER
1
LOAD
1
2
2
1
2
JT
AXIAL
SHEAR- SHEAR- TORSION MOMY
Z
MOM-
Y
Z
1
-3.92
0.00
0.00
0.00
0.00
0.00
2
3.92
0.00
0.00
0.00
0.00
0.00
1
0.00
0.00
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
2
-1.47
0.00
0.00
0.00
0.00
0.00
3
1. 47
0.00
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
3
0.00
0.00
0.00
0.00
0.00
0.00
50
3
1
2
4
1
2
5
1
2
6
1
2
7
1
2
3
-0.65
0.00
0.00
0.00
0.00
0.00
4
0.65
0.00
0.00
0.00
0.00
0.00
3
0.00
0.00
0.00
0.00
0.00
0.00
4
0.00
0.00
0.00
0.00
0.00
0.00
4
3.27
0.00
0.00
0.00
0.00
0.00
5
-3.27
0.00
0.00
0.00
0.00
0.00
4
0.00
0.00
0.00
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
0.00
5
3.43
0.00
0.00
0.00
0.00
0.00
6
-3.43
0.00
0.00
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
0.00
6
0.00
0.00
0.00
0.00
0.00
0.00
6
-3.92
0.00
0.00
0.00
0.00
0.00
7
3.92
0.00
0.00
0.00
0.00
0.00
6
0.00
0.00
0.00
0.00
0.00
0.00
7
0.00
0.00
0.00
0.00
0.00
0.00
7
0.00
0.00
0.00
0.00
0.00
0.00
8
0.00
0.00
0.00
0.00
0.00
0.00
7
0.00
0.00
0.00
0.00
0.00
0.00
8
0.00
0.00
0.00
0.00
0.00
0.00
51
8
1
2
9
1
2
10
1
2
11
1
2
12
1
2
8
0.00
0.00
0.00
0.00
0.00
0.00
9
0.00
0.00
0.00
0.00
0.00
0.00
8
0.00
0.00
0.00
0.00
0.00
0.00
9
0.00
0.00
0.00
0.00
0.00
0.00
9
-10.34
0.00
0.00
0.00
0.00
0.00
10
10.34
0.00
0.00
0.00
0.00
0.00
9
0.00
0.00
0.00
0.00
0.00
0.00
10
0.00
0.00
0.00
0.00
0.00
0.00
10
-16.63
0.00
0.00
0.00
0.00
0.00
11
16.63
0.00
0.00
0.00
0.00
0.00
10
0.00
0.00
0.00
0.00
0.00
0.00
11
0.00
0.00
0.00
0.00
0.00
0.00
11
-17.98
0.00
0.00
0.00
0.00
0.00
12
17.98
0.00
0.00
0.00
0.00
0.00
11
0.00
0.00
0.00
0.00
0.00
0.00
12
0.00
0 00
0.00
0.00
0.00
0.00
12
7.19
0.00
0.00
0.00
0.00
0.00
1
-7.19
0.00
0.00
0.00
0.00
0.00
12
0.00
0.00
0.00
0.00
0.00
0.00
1
0.00
0.00
0.00
0.00
0.00
0.00
52
13
1
2
14
1
2
15
1
2
16
1
2
17
1
2
2
1.95
0.00
0.00
0.00
0.00
0.00
12
-1.95
0.00
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
12
0.00
0.00
0.00
0.00
0.00
0.00
3
-0.59
0.00
0.00
0.00
0.00
0.00
11
0.59
0.00
0.00
0.00
0.00
0.00
3
0.00
0.00
0.00
0.00
0.00
0.00
11
0.00
0.00
0.00
0.00
0.00
0.00
4
0.52
0.00
0.00
0.00
0.00
0.00
10
-0.52
0.00
0.00
0.00
0.00
0.00
4
0.00
0.00
0.00
0.00
0.00
0.00
10
0.00
0.00
0.00
0.00
0.00
0.00
5
4 .49
0.00
0.00
0.00
0.00
0.00
9
-4.49
0.00
0.00
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
0.00
9
0.00
0.00
0.00
0.00
0.00
0.00
6
8 .99
0.00
0.00
0.00
0.00
0.00
a
-8.99
0.00
0.00
0.00
0.00
0.00
6
0.00
0.00
0.00
0.00
0.00
0.00
a
0.00
0.00
0.00
0.00
0.00
0.00
53
18
1
2
19
1
2
20
1
2
21
1
2
2
1. 47
0.00
0.00
0.00
0.00
0.00
11
-1.47
0.00
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
11
0.00
0.00
0.00
0.00
0.00
0.00
3
3.77
0.00
0.00
0.00
0.00
0.00
10
-3.77
0.00
0.00
0.00
0.00
0.00
3
0.00
0.00
0.00
0.00
0.00
0.00
10
0.00
0.00
0.00
0.00
0.00
0.00
5
-4.57
0.00
0.00
0.00
0.00
0.00
10
4 .57
0.00
0.00
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
0.00
10
0.00
0.00
0.00
0.00
0.00
0.00
6
-11.27
0.00
0.00
0.00
0.00
0.00
9
11.27
0.00
0.00
0.00
0.00
0.00
6
0.00
0.00
0.00
0.00
0.00
0.00
9
0.00
0.00
0.00
0.00
0.00
0.00
54
5.2.6 Design of Foundation
It is essential to carry out investigation before preparing the design of civil engineering works. The investigation may range in scope from simple examination of the surface soils, with or without a few shallow trial pits, to a detailed study of the soil and ground water conditions for a considerable depth below the ground surface by means of boreholes and in-situ and/ or laboratory test on the soils encountered. The extent of the investigation depends on the importance of the structure, the complexity of the soil conditions, and the information already available on the behavior of the existing foundations similar on soils. Thus, it is not the normal practice to sink boreholes and carry out soil tests for single or two story structure since normally, there is adequate knowledge of the safe bearing pressure of the soil in any particular locality. Only in troublesome soils such as peat or loose fill would it be necessary to sink deep boreholes, possibly supplemented by soil test. More extensive ground conditions where there is no information available on foundation behavior of similar structures. Since the structure to be design is school building, it is very important to consider the type of soil to design the foundation efficiently and precisely. The type of soil to be design is the clayey soil thereore we use “rat” or matt oundation Information was extracted from site investigation to facilitate foundation design. This includes
General topography of the site which affects foundation design and construction e.g., surface configuration, adjacent property, presence of water course, and so on.
Location of buried services such as power lines, telephone cables, water mains, sewer pipes and so on.
General geology of the area within particular reference to the principal geological formations underlying the site.
Previous history and use of the site including information of any defects and failures of structure built on the site.
55
Any special features such as possibility o0f earthquake, flooding, seasonal swelling etc.
Availability and quality of local construction materials.
A detailed record of soil rock strata, ground water conditions within the zone affected by foundation loading and of any deeper strata affecting the site conditions in any way.
In designing the foundation of the structure, SAFE application was used. SAFE application is software that focuses on foundation design. This software designs different footings, from square footings, rectangular footings, combined footings, to matt footings and other kinds of footings. In the design of footings Structural Analysis of Finite Element was used. Matt Foundation is the type of foundation to be used in the design of substructure of the proposed building. SAFE is the ultimate tool for designing concrete floor and foundation systems. From framing layout all the way through to detail drawing production, SAFE integrates every aspect of the engineering design process in one easy and intuitive environment. It provides unmatched benefits to the engineer with its truly unique combination of power, comprehensive capabilities, and ease-of-use. Laying out models is quick and efficient with the sophisticated drawing tools, or use one of the import options to bring in data from CAD, spreadsheet, or database programs. Slabs or foundations can be of any shape, and can include edges shaped with circular and spline curves. Post-tensioning may be included in both slabs and beams to balance a percentage of the self-weight. Suspended slabs can include flat, two-way, waffle, and ribbed framing systems. Models can have columns, braces, walls, and ramps connected from the floors above and below. Walls can be modeled as either straight or curved. We used raft foundation in designing soil foundation including different parameters used in mat foundation design. Modulus of subgrade reaction, assumptions and considerations to analyze mat as rigid or flexible foundation, loads that should account in mat foundation design, thickness rigidity relationship of mat, and thickness deflection relationship of mat was analyzed in the foundation design. In this post, we learned about analysis model that are used in computer software SAFE.
56
In this model finite elements are formed from object based model. Rectangular finite element mesh is developed depending on maximum allowable element size.
Computer oriented method for structural analysis is used to solve plates (raft) supported on elastic foundation. These rectangular finite elements are interconnected to adjacent one only at corners (nodes) and a isolated spring that resembles to soil are used in modeling. Raft foundation is analyzed in SAFE based on classical theory for thick plates supported on the winkler foundations. The isolated spring assumed in modeling soil is called winkler foundation. This theory takes in to account the deformation due to transverse shear of the plate. This model is shown in the figure below. Mat foundations can include nonlinear uplift from the soil springs, and a nonlinear cracked analysis is available for slabs. Generating pattern surface loads is easily done by SAFE with an automated option. Design strips can be generated by SAFE or drawn in a completely arbitrary manner by the user, with complete control provided
57
for locating and sizing the calculated reinforcement. Finite element design without strips is also available and useful for slabs with complex geometries. Comprehensive and customizable reports are available for all an alysis and design results. Detailed plans, sections, elevations, schedules, and tables may be generated, viewed, and printed from within SAFE or ex ported to CAD packages. SAFE provides an immensely capable yet easy-to-use program for structural designers, providing the only tool necessary for the modeling, analysis, design, and detailing of concrete slab systems and foundations.
58
5.2.6.1 Introduction
In designing the foundation of the structure, SAFE application was used. SAFE application is software that focuses on foundation design. This software designs different footings, from square footings, rectangular footings, combined footings, to matt footings and other kinds of footings. In the design of footings Structural Analysis of Finite Element was used. Matt Foundation is the type of foundation to be used in the design of substructure of the proposed building. From the recommended soil investigation, the presence of the very loose/soft alluvial deposits between 0 to 9m depth would discourage the use of a shallow foundation. This layer is settlement prone and/or highly compressible based on the SPT blow counts. It is also strongly susceptible to liquefaction during a strong earthquake, causing major damage to the structure under such an event. The soil bearing capacity is estimated to be less than 25 kpa, considerably too low to support the structure without shear failure and the settlement is extremely very ex cessive. Higher bearing pressures of as high as 250 kPa can be generated below the bottom level of the alluvium. However, this will require mat footings and a deep foundation involving piles just to reach the hard strata wherein the stability of the foundation can be assured. Properties of Concrete to be considered in S AFE software: Concrete Compressive Strength ’c Mpa Modulus of Elasticity, E = 24650 Mpa
59
Properties of rebars to be considered in SAFE software: 3
Weight Per unit Volume, 77 KN/m
Modulus of Elasticity, E =200000 Mpa Fy = 414 Mpa Fu= 550 Mpa
Fig. 5.1 Shorter Direction Top Bar
60
Fig. 5.2 Longer Direction Top Bar
Fig 5.3 Shorter Direction Bottom Bar
61
Fig 5.4 Longer Direction Bottom Bar
Soil Subgrade Modulus
Subgrade modulus of the soil from soft up to the hardest part which is bed 3
rock may vary from 100 to 500 lb/ in . From the soil investigation report, the subgrade modulus of the soil was 3
found to be clayey which makes the value up to 100 lb/ in .
x
x
x
x
3
= 27000 KN/m
x
62
After run analysis ..
Fig. 5.5Longer Direction Bottom Bar Result
Fig 5.6 Longer Direction Bottom Bar Result
63
Fig 5.7 Shorter Direction Top Rebar Result
Fig5.8 Shorter Direction Top Rebar Result
64
5.2.7 Design of Concrete Mix
A concrete mix proportion requires an intelligent guess of optimum combination based on previous experiences or relationships previously derived. The process to obtain a satisfactory mix starts with:
Preliminary Computations
Trial Mix
Checking
Adjustments
Trial Mix
Concrete mix proportioning must be executed properly. External factors, such as moisture condition of aggregates, place where mixing is to be conducted; handling, placing, transporting and weather conditions affect fresh and hardened properties of a designed mix. There are two applicable methods employed in designing the concrete proportions, based on a Philippine setting. Under the ACI method, the absolute volume of a concrete mix is taken to be one cubic unit of the material; thus, the sum of the proportions of cement, water, air entrainments and aggregates must also be equal to 1 cubic unit by definition of concrete itself. On the other hand, the approximate sand-andwater content method, a required submittal by the Department of Public Works and Highways (DPWH), makes use of three basic specifications: a) the water-cement ratio is taken to be 0.57, b) the fineness modulus (FM) of sand is 2.75, and c) slump of concrete is 75 mm. In excess of these parameters, corrections among the proportions must be applied in order to comply with these requirements. Compared to the absolute volume of the concrete mix adopted in ACI method, it is taken as the reciprocal of the cement factor (CF), which is expressed in the number of bags of cement needed to make per 1 cubic unit of concrete. Similarly, the sum of the proportions of cement, water, air entrainments and aggregates must also be equal to that amount.
It is to be noted that the proportions to be prepared under either of the two methods are starting mixes only. In the course of mixing operations, the quality of concrete should be
65
periodically checked for the following: workability, net water content and cement as per yield test. Should it fail to meet the requirements according to the method employed, adjustments shall be made to ensure the consistency of concrete throughout the structure.
The following presents the steps employed in designing a concrete mix: Method 1 – The ACI Method
1) Given the design compressive strength o concrete, c’, identi the corresponding water-cement ratio (Table E-3). Interpolation might be needed.
2) Obtain the water requirement (Table E-4) taking the following parameters: a) Type of Coarse aggregates (Angular/Rounded) b) Maximum Aggregate Size (MAS) c) Slump
3) From the corresponding water requirement, identify the percentage of entrapped air (Table E-4).
4) Use Table E-5 to identify the volume of coarse aggregates given the following parameters: a) Fineness modulus (sand) b) MAS
5) Number of bags of cement required N =
6) Absolute volume of cement |Vcement| =
(Gc = sp.gr. of cement)
66
7) Absolute volume of water |Vwat| =
8) Absolute volume of air = 1 x % entrapped (item 3) 9) Absolute volume of cement paste (|Vp|) = sum of items 6, 7 and 8 10) Absolute volume of solid aggregates = 1 - |Vp| 11) Absolute volume of gravel: =
12) Absolute volume of sand: = Absolute Vol. of Solid Aggregates – Absolute Vol. of Gravel
Correcting the quantities of water, sand and gravel
13)
Field Moisture (FM) = moisture content - absorption
14) Correction of Weight of Sand and Gravel Corr. = Uncorr. (1 +
)
15) Corrected Quantity of Water Corr. = Uncorr. – (Δs Δg Δ ) Δs, Δg, Δ = difference between the corrected and uncorrected weights of sand, gravel and air, respectively, 16) Tabulate Results (Sample Below):
67
Material
Abs. Volume
Sp. Gr
ϒH2O
Uncorrected
Corrected Wt.
Wt. (kg)
(kg)
Cement Sand Gravel Water Air
17) Quantity Take-off (for filling a structural component)
Wt. of material =
V is the volume of the structural element required to fill. *Considering quantity losses , multiply the quantity of material by 1.1
The concrete mix design concrete must produce a workable concrete mixture having properties that will not exceed the maximum and/or minimum values defined in the special provision. Workability in concrete defines its capacity to be placed, consolidated, and finished without harmful segregation or bleeding. Workability is affected by aggregate gradation, particle shape, proportioning of aggregate, amount and qualities of cementitious materials, presence of entrained air, amount and quality of high range water reducer, and consistency of mixture. Consistency of the concrete mixture is its relative mobility and is measured in terms of slump. The higher the slump the more mobile the concrete, affecting the ease with which the concrete will flow during placement. Consistency is not synonymous with workability. Two different mix designs may have the same slump; however, their workability may be different. The qualities of the cementitious paste provide a primary influence on the properties
of
concrete.
Proper
selection
of
the
cementitious
content
and
68
water/cementitious ratio is dependent on the experience of the concrete producer and becomes a very important first step in preparing a design. For workable concrete, a higher water cementitious ratio is typically required when aggregate becomes more angular and rough textured. The presence of air, certain pozzolans, and aggregate proportioning will work to lower the water cementitious ratio; however the most significant reduction in water demand comes through the use of high range water reducing chemical admixture. Water/cementitious ratio is determined from the net, per unit, quantity of water and total cementitious materials (by weight). The net water content excludes water that is absorbed by the aggregates. For a given set of materials and conditions, as water/cementitious ratio increases, strength and unit weight will decrease. Compressive strength is a concrete parameter used in combination with unit weight and air content to evaluate the durability of the superstructure concrete's exposure to freeze / thaw action, and exposure to deicing salts. It is important to note that the designer of the bridge structure does not recognize the benefit of increased compressive strength. The slab still relies on a minimum design compressive strength (f'c) of 4000 psi at 28-days. Proportioning of aggregates is defined by the volume of fine aggregate to the volume of coarse aggregate, as a percent. The lower percentage of fine to total aggregate provides an increase in compressive strength at the expense of workability. The gradation, particle shape and texture of the coarse aggregate along with fineness modulus of the fine aggregate will determine how low the fine to total aggregate percentage can be for a given workability requirement. Once the cement content, pozzolan content, water/cementitious ratio, and fine to total aggregate percentage are defined for the concrete's intended use in the superstructure, proportioning of the mix in terms of design batch weights can begin. Specific gravities must be accurately defined for each material being utilized in order to proportion the mix properly by the absolute volume method. Cement is typically accepted as having a specific gravity of 3.15. Pozzolans will typically vary between 2.22 and 2.77 depending on the type of pozzolan (fly ash, GGBFS, silica fume) and its source. Pozzolan suppliers should readily be able to provide current values for their material. Approximate specific
gravities
are
identified
for
each
source
on
the
Department's
69
Approved/Prequalified Materials list; however, they should not be considered the most current. Bulk specific gravity, in the saturated surface dry condition, must be used to proportion the fine and coarse aggregate. Accurate testing of one or more samples of fine and coarse aggregate must be accomplished by the Contractor as part of any proportioning for a mix design. It is of great benefit to identify the geologic ledges from which a crushed stone coarse aggregate is produced. Subsequent shifts in benching at the aggregate source may cause significant shifts in bulk specific gravity and absorption. These are important aggregate properties to monitor as part of concrete quality control. Proportioning concrete by the absolute volume method involves calculating the volume 3
3
of each ingredient and its contribution to making one yd or 27 ft of concrete. Volumes are subsequently converted to design weights, which then become the basis for actual production of concrete from the plant. For cementitious materials and water, the weight to volume conversion is accomplished by dividing the weight (lbs) by the specific gravity 3
of the material and again dividing by the density of water (62.27 lbs/ft at 73.4 °F). Converting from volume to weight is accomplished simply by taking the known volume 3
(ft ) of the ingredient and multiplying by the specific gravity of the ingredient and again 3
multiplying by the density of water (62.27 lbs/ft at 73.4 °F). Volume to weight conversions for aggregates is accomplished by the same series of computations; however, bulk specific gravity (SSD) must be used. The target air content is established at 6.5% by 3
the special provision, which converts to a volume of 1.76 ft within a cubic yard of concrete.
70
(Using ACI Method) Portland Cement
Type I
Type of Aggregate
Angular
Max Size of Coarse Aggregates
19
mm
Max Density of Water
1000
kg/m
Wt. of Cement
40
kg/bag
Slump
75 to 100
mm
1586.28
kg/m
Cement
Sand
Gravel
Fineness Modulus
-
2.4
-
Sp. Gravity
3.2
2.57
2.5
Moisture Content
5.4
2.99
Absorption
2.33
2.33
Natural
Angular
3
Unit Wt. of Coarse Aggregate.
Type
I
3
TABLE5.5: Summary of Concrete-Mix Parameters from Material Testing
1) Water-Cement Ratio (From Table E-3) W-C Ratio (L/40kg
Value
Strength (MPa)
Upper Limit
34.47
17.75
Required
28.00
-
Lower Limit
27.58
21.30
bag)
71
=
= 18 L/40 kg bag
2) Water Requirement (From Table E-4)
MAS = 19 mm
Type = Angular
Slump = 75 – 100
Use: 0.018m x
3
= 18 L
3) Entrapped Air: (From Table E-4)
From corresponding column in item (2)
2%
4) Volume of Coarse Aggregate
MAS: 19 mm
FM of Sand = 2.37 Absolute Vol. of Coarse
Value
Fineness Modulus of
3
Aggregate (m )
Sand
2.40
0.65
Required
2.37
?
Upper Limit
2.60
0.63
Lower Limit
x = 0.653
5) Number of bags per volume of concrete: (Calc. W/C Ratio)
=
= 9.63 bags of cement
6) Absolute volume of cement
72
|Vcement| =
3
= 0.1204 m
7) Absolute volume of water |Vwat| =
= 0.2030 m3
8) Absolute volume of air = 1 x 0.02 = 0.02
9) Absolute volume of cement paste (|Vp|)
= 0.1204 + 0.2030 + 0.02 = 0.3434
10) Absolute volume of solid aggregates
= 1 – 0.3434 = 0.6566
11) Absolute volume of gravel:
=
= 0.426
12) Absolute volume of sand: = 0.6566 – 0.4143 = 0.378
73
Table 5.6 A tabulated summary of computed values is shown below:
Material
Abs. Volume
Uncorrected
Corrected Wt.
Wt. (kg)
(kg)
Sp. Gr
ϒH2O
1000.00
40
1000.00
101.68
Cement
0.1270
3.15
Sand
0.378
2.69
Gravel
0.426
2.731
Water
0.20
1.00
Air
0.02
-
1000.00
1000.00 -
116.34
18
(required to find) (required to find) (required to find) (required to find)
74
Chapter 6 Budget Estimation Based on the estimates made for the design of A Proposed Five-Storey School Building with the Use of Fly Ash as an Alternative Material for Portland Cement at St. Anthony School, San Andres Manila, it is established that the total cost of the design was estimated to be amounting of Php 57,896,081.50 with an area of 810.25 sq.m.. Without having the flyash as an additive to portland cement the probable cause of our proposed project will be Php 58,528,408.81, it saves about Php 632,327.31.
Since construction costs are incurred over the entire construction phase of a project, it is often necessary to determine the amounts to be spent in various periods to derive the cash flow profile, especially for large projects with long durations. Consequently, it is important to examine the percentage of work expected to be completed at various time periods to which the costs would be charged. More accurate estimates may be accomplished once the project is scheduled, but some rough estimate of the cash flow may be required prior to this time.
In general, the work on a construction project progresses gradually from the time of mobilization until it reaches a plateau; then the work slows down gradually and finally stops at the time of completion.
The contractor's bid estimate often reflects the desire of the contractor to win the job as well as the estimating tools at its disposal. The larger contractors have wellestablished cost-estimating procedures while others do not and rely on publicly available pricing information or a rough estimate of their time and resources. Since only one tendering contractor will be successful, all effort devoted to cost estimating will be a loss to the contractors who are not successful.
75
In many cases when the cost estimate indicates that the project costs will exceed the available funds, the owner and architect will identify a list of alternates which are items that are to be either added back into the project if the bids are lower than anticipated, or deducts which are then deleted from the project if the bids run too high. Alternates which are identified for deletion are items which usually do not affect the functionality or the basic program for the facility, but require qualitative changes to the materials or design. The cost estimate accounts for all items that will generally be included in the general contractor’s id The cost estimate is prepared reaking down the items of work using a standard format and determining the cost of each item from experience and a database of current construction cost information.
76
A more
reliable method
is based
on the
concept of value of work
completed which is defined as the product of the budgeted labor hours per unit of production and the actual number of production units completed, and is expressed in budgeted labor hours for the work completed. Then, the percentage of completion at any stage is the ratio of the value of work completed to date and the value of work to be completed for the entire project. Regardless of the method of measurement, it is informative to understand the trend of work progress during construction for evaluation and control.
Consequently, the contractor may put in the least amount of possible effort for making a cost estimate if it believes that its chance of success is not high. If a tendering contractor intends to subcontract parts of the project, it may request price quotations for the various tasks to be subcontracted to appropriate specialized firms. Therefore, the general subcontractor shifts the burden of cost estimating to subcontractors. If all or part of the construction is to be u ndertaken by the main contractor themselves, a bid estimate may be prepared on the basis of the quantity takeoffs from the drawings provided by the client or on the basis of the construction procedures devised by the contractor for implementing the project. I*'or example, the cost of a pad foundation of a certain type and size may be found in commercial publications on cost data which can be used to facilitate cost estimates from quantity takeoffs.
However, the contractor may wish to assess the actual cost of construction by considering the actual construction procedures to be used and the associated costs if the project is deemed to he different from typical designs. Hence, items such as labour, material and equipment needed to perform various tasks should always be taken into consideration for the cost estimates.
Budget Estimation PROJECT :Proposed Five Storey Building LOCATION:San LOCATION:San Andres St. corner Singalong St. Malate Manila SUBJECT : Budgetary Budgetary Cost Estimate Estimate ITEM I. 1 2 3 4 5 6 7 8 9
II 1.0
2.0 3.0 4.0 5.0 6.0 7.0
Description of Work GENERAL REQUIREMENT: MOBILIZATION MOBILIZAT ION : Demobilization Demobilizat ion Temporary Facilities Facilit ies Plans,Documentation,& Plans,Docum entation,& Fees Permits & Licenses Bonds & Insurance Premium for Contractor's All-Risk All-Ris k Insurance Security ,Safety,Medical ,Communication ,Communication & Testing Temp. Water & power suppies EARTH WORKS : Excavation: a. Mechanical / Equipment b. Manual Earthfill Earthfil l /backfilling /backfilli ng with compaction Dewatering Gravel fill ( Gravl Bedding) Soil poisoning Polythelene sheet(Moisture Protection) Hauling of unsuitable materials
Qty.
Unit
1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
lot lot lot lot lot lot lot lot lot
1,554.00 666.00 1,620.00 1.00 74.00 880.00 740.00 1.00
cu.m. cu.m. cu.m. lot cu.m. sq.m. sq.m. lot
MATERIAL / LABOR Unit Cost Amount 50,000.00 50,000.00 100,000.00 100,000.00 150,000.00 150,000.00 150,000.00 150,000.00 120,000.00 120,000.00 70,000.00 70,000.00 190,000.00 190,000.00 250,000.00 250,000.00 250,000.00 90,000.00 90,000.00 Sub-total. 1,170,000.00
600.00 550.00 250.00 50,000.00 720.00 75.00 60.00 100,000.00 Sub-total.
935,760.00 366,300.00 366,300.00 405,000.00 50,000.00 53,280.00 66,000.00 44,400.00 100,000.00 2,020,740.00
77
III A 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0
CIVIL / STRUCTURAL WORKS: CONCRETE IN-PLACE Slab on fill ( Concrete w/ flyash3,000 flyash3,000 psi) Footing Foundadation ( concrete w/ flyash 4,000 psi) Column Beams Suspended slab Cistern tank Septic tank Stairs Linter Beam /Stiffiner column
B 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 C. 1.0 2.0 3.0 4.0 5.0 6.0
74.00 444.00 172.8 336.00 370.00 63.00 32.00 70.00 22.00
cu.m. cu.m. cu.m. cu.m. cu.m. cu.m. cu.m. cu.m. cu.m.
4,500.00 4,950.00 4,950.00 4,950.00 4,950.00 4,950.00 4,950.00 4,950.00 4,950.00 Sub-total.
333,000.00 333,000.00 2,197,800.00 855,360.00 1,663,200.00 1,831,500.00 311,850.00 158,400.00 346,500.00 108,900.00 108,900.00 7,806,510.00
REBARS IN-PLACE Slab on fill Footing Foundadation Column Beams Suspended slab Cistern tank Septic tank Stairs Linter Beam /Stiffiner /Stif finer column
2,516.00 53,762.50 53,481.60 73,584.00 42,180.00 6,615.00 5,920.00 7,742.00 1,485.00
kgs. kgs. kgs. kgs. kgs. kgs. kgs. kgs. kgs.
65.00 65.00 65.00 65.00 65.00 65.00 65.00 65.00 65.00 Sub-total.
163,540.00 3,494,562.50 3,476,304.00 4,782,960.00 2,741,700.00 429,975.00 384,800.00 503,230.00 96,525.00 16,073,596.50
FORM WORKS: Footing Foundadation Column Beams Suspended slab Cistern tank Septic tank
432.00 1,297.50 2,100.00 3,341.00 410.00 208.00
sq.m. sq.m. sq.m. sq.m. sq.m. sq.m.
610.00 610.00 610.00 610.00 610.00 610.00
263,520.00 792,085.00 1,281,000.00 2,038,010.00 250,100.00 126,880.00 78
7.0 8.0
Stair Linter Beam /Stiffiner column
455.00 72.00
sq.m. sq.m.
610.00 610.00 Sub-total.
277,550.00 43,920.00 5,073,065.00
VI 1 2
ROOFING WORKS: Structural Roof Truss Polycarconate Sheet 4.5 mm Thk.
79.00 79.00
sq.m. sq.m.
1,600.00 1200.00 Sub-total.
126,400.00 94,800.00 221,200.00
VII 1.0
ARCHITECTURAL WORKS: MASONRY : Laying of CHB 4" ( 100mmThk) Laying of CHB 6" (150mm Thk.) PLAIN CEMENT PLASTERING a. Exterior Cement Plastering Plasteri ng b. InteriorCement InteriorCement Plastering TILE WORKS: a. Floor tiles Homogeneous non -skid tiles b.Wall tiles ( Toilet partition) partition) c. Marble finish
216.00 1,910.00
sq.m. sq.m.
485.00 685.00
104,760.00 1,308,350.00
840.00 3,530.00
sq.m. sq.m.
380.00 350.00
319,200.00 1,235,500.00 1,235,500.00
3,520.00 432.00 12.00
sq.m. sq.m. sq.m.
1,000.00 950.00 4,500.00 Sub-total.
3,520,000.00 410,400.00 410,400.00 54,000.00 6,952,210.00
CEILING WORKS a.Rubbed concrete b.Ficem board 4.5mm thk. For For C.R.
3,263.00 330.00
sq.m. sq.m.
80.00 850.00
216,040.00 280,500.00 280,500.00
PAINTING WORKS a. Exterior Wall b. Interior wall wall c. Ceiling d Steel casement Windows / Louver Window e. Wood Doors
840.00 330.00 860.00 1,326.00 262.00
sq.m. sq.m. sq.m. sq.m. sq.m.
250.00 220.00 220.00 220.00 250.00 Sub-total.
210,000.00 72,600.00 189,200.00 291,720.00 65,500.00 829,020.00
2.0
3.0
4.0
5.0
79
6.0
7.0
8.0
9.0
VIII
MILL WORKS with / FINISH HARDWARE: a. Solid Wood DOORS b. Hollow core wood flush door (Marine) for toilet b. CUBICLE DOOR ( Laminated)
54.00 10.00 56.00
sets sets sets
13,500.00 8,500.00 4,500.00 Sub-total.
729,000.00 85,000.00 252,000.00 1,066,000.00
78.00 78.00
sets sets
10,500.00 8,700.00
819,000.00 678,600.00
20.00
sets
12,000.00
240,000.00
METAL WORKS a.Steel Casement Window with glass 5mm thk. b. Awning Aluminum Window with glass-5mm thk. c. Steel Louver Window @ Stair portion(Ventilating window) d. Steel Louver Window @ roof deck( Ventilating window) e. Stair Railing f. Balcony Railing
8.00
sets
12,000.00
96,000.00
226.50 36.00
lm. lm.
1,200.00 1,200.00 Sub-total.
271,800.00 43,200.00 2,148,600.00
CARPENTRY WORKS: a. Blackboard w/ frame b. Flat form c. Fisem board ceiling
27.00 27.00 330.00
sq.m. sq.m. sq.m.
10,000.00 11,000.00 850.00 Sub-total.
270,000.00 297,000.00 280,500.00 847,500.00
WATER PROOFING WORKS: a. Comfort room b. Roof Deck with concrete topping c. Fire wall ( Damproofing)
330.00 105.00 516.20
sq.m. sq.m. sq.m.
750.00 1,300.00 650.00 Sub-total.
247,500.00 136,500.00 335,400.00 719,400.00
70.00 20.00 40.00
sets sets sets
6,000.00 4,000.00 3,500.00
420,000.00 80,000.00 140,000.00
SANITARY / PLUMBING WORKS: a. Water closet b. Urina c. Lavatory
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d. Floor drain(Jaman) e. Plumbing Fittings & accessories f. Inatallation of cold water line g. Installation of sewer line h. Drainages line connecting to existing i. Over head water tank 4,000 gals. j. 5Hp Transfer pump k. 5 Hp Buster pump
50.00 1.00 1.00 1.00 1.00 1.00 2.00 2.00
pcs. lot lot lot lot lot units units
450.00 80,000.00 667,500.00 295,000.00 150,000.00 350,000.00 56,000.00 52,000.00 Sub-total.
22,500.00 80,000.00 667,500.00 295,000.00 150,000.00 350,000.00 112,000.00 104,000.00 2,421,000.00
ELECTRICAL WORKS: a. Roughing -in b. Lighting fixtures c. Wires & Cables f. Wiring devices g. Panel board Main CB 800 A
1.00 1.00 1.00 1.00 1.00
lot lot lot lot lot
421,000.00 395,500.00 325,000.00 154,000.00 435,000.00 Sub-total.
421,000.00 395,500.00 325,000.00 154,000.00 435,000.00 1,730,500.00
X
FIRE PROTECTION SYSTEM:
1.00
lot
4,500,000.00
4,500,000.00
XI
CONSTRUCTION MANAGEMENT FEE
1.00
lot
1,500,000.00
1,500,000.00
XII
ARCHITECT & ENGINEERS DESIGNERS FEE TOTAL PROJECT COST
1.00
lot
2,325,000.00 GRAND TOTAL
2,325,000.00 57,896,081.50
IX
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Chapter 7 Project Schedule
Prior to beginning project construction, the contractor normally prepares a bill of material that lists the types of material, the amount, the supplier and the cost. The bill of material also should relate the material to the specific construction activity. Purchase order is an agreement to purchase items from a supplier and may include several different materials and activity codes and multiple delivery dates. The purchase order is used for ordering material and for payment by accounting.
Note that not only the plan and the schedule are related, but also many of the elements of the plan are interrelated. For example, most of the choices in the plan (length of stay, type of accommodations, means of transportation, type of activities, food, etc.) affect the budget. Since different means of transportation have longer time durations than others, they may affect not only the cost but the schedule as well. Clearly, a lack of clarity of scope before the project starts may lead to heated arguments and dissatisfaction. In real projects, it may lead to huge budget overruns, schedule delays, and different 1
parties dissatisfaction. Therefore, it is important to have a clear understanding of the project's scope (objectives), and decide who the "project manager" is. Many issues are at stake in this example, but demonstrating the concepts of planning and scheduling is our objective.
Once a project starts, certain aspects can easily deviate or go astray. This deviation can be overspending, a schedule slippage, a departure from the objective/scope, or something else. It is of utmost importance to know — at all times — where you stand in relation to where you planned to be (the baseline). If you find yourself behind schedule or over budget, you must know why and then take corrective action to get back on track or, at least, minimize the deviation. If the deviation is positive, actual performance was probably better than that expected in the baseline plan.
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Planning, scheduling, and project control arc extremely important components of project management. However, project management includes other components, such as cost estimating and management, procurement, project/contract administration, quality management, and safety management. These components are all interrelated in different ways. The group of people representing all these disciplines is called the project management team. It is usually headed by the project manager (PM).
Fog 7.1 Gantt Chart
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Fig 7.2Project Network Diagram
Fig. 7.3 Project Calenda
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Fig 7.4 Project Team Planner
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Chapter 8 Promotional Materials
Perspective View
Front Elevation
87
Rear Elevation
Left Elevation
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Conclusion and Summary
The stud is entitled “A Proposed Five-Storey School Building With the Use of Fly Ash as an Additive Material for Portland Cement at St. Anthony School, San Andres Manila” Through eperiment indings on the mixing of fly ash from concrete cement this study arrived at a slower phase of increase in strength than an ordinary mixture of plain concrete cement. Even though its rate of increase strength is gradual over plain cement, its phase of development for compressive strength exceeds than of plain cement after one or two months of duration.
50 45
44.45
) 40 a P M35 ( h t g 30 n e r t 25 S e v i s s 20 e r p 15 m o C 10
38.25 35.46
5 0 0
5
10
15
20
25
30
Age (Days)
Fig.9.0 Ratio between Compressive Strength and Time
Statistical analyses of compression tests have shown that the use of fly ash often lowers the variability of strengths (lower coefficient of variation). This can result in a reduction in “overdesign”, ielding a direct cost savings to the concrete producer by increasing compressive strength.
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Fly ash is an integral material to be added to the plain cement. From the different studies made and which have been proven, it can be concluded that as the age of the material continues to increase the durability and strength imply that it is safe for building construction.
Fly ash is one of the materials that comply with green engineering. This is a waste material coming from manufacturing industries, particularly from power plants. In the Philippines, coal power plants are one of the major producers of fly ash. From the production of electricity, waste is generated from burning coal--ash. These ashes are characterized by different abilities. Different countries regulate waste generation to reduce the pollution created by coal power plants. There will be a big impact on the environment since 40% of the electricity in the Philippines is generated by coal power plants.
There is much potential from the properties and chemistry of fly ash. There are a lot of benefits if the government regulates and fully utilizes the fly ash from power plants. If implemented wisely and regularly, community projects such as housing can be boosted through the use of fly ash products. Vulnerable coastal areas could be protected by seawater breakers made of fly ash concrete Earning “caron credits” is a possiilit because 30% less cement needs to be manufactured.
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Recommendations
Further studies should be done to consider more use of fly ash in the country in order to reduce the project cost of a structure especially in the production of concrete mix. Moreover this waste product of power plants will have a positive environmental impact when used as an additive in the concrete mix.
Further studies should also be done to consider the conservation of energy like applying metal louvers to surround a building as the air ventilation for the whole building in order to optimize the capabilities of the structure and to further boost the potential of a structure as being eco-friendly and economical.
Finally, further studies should also be done to improve the function of the structure and to improve its overall potential for providing good service to humans as well as to nature.
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Acknowledgement We owe our deepest gratitude to our Almighty Father, who has given us an opportunity to learn, to explore and to discover new things in our thesis and to be able to apply what we have learned in our previous subjects.
We would like to thank our parents especially to Engr. Victor and Helen Mallillin, Mr. Francisco Punzalan and Mrs. Amalia Punzalan , and Angelica Mallillin
who are always there to support us in our studies and for always looking forward to our good career. They always become inspirations for us to pursue the path we choose despite various difficulties. We would also like to thank our thesis adviser, Engr. Divina Gonzales, who was always there when we encountered difficulties and if we had
questions in our thesis.
In addition, we would like to thank our thesis professor, Engr. Francis Aldrine Uy, who has the attitude and characteristics of being a great engineer; he taught us and
guided us all throughout our thesis. Without his guidance and persistent help this thesis project would not have been possible. I thank Pozzolanic Philippines Incorporated who provided us data and materials for the comparative analysis of cement and fly ash.
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References
Abdullah et al. (2011). Malaysia Fly Ash Based Geopolymer Cement and Concrete. Lambert Academic Publisher ASEP (2010). National Strucutral Code of the Philippines 2010, 6th edition, volume 1 (Buildings, Towers and Other Vertical Structures). Helmuth, R. (1987) Fly Ash in Cement and Concrete.
INTRON (1992). Fly Ash as Addition to Concrete: Research carried out by INTRON, Institute for Material and Environmental Research, Netherlands.
Joshi, R. & Lohita, R. (1997). Fly Ash in Concrete: Production, Properties and Uses (Advances in Concrete Technology). Gordon and Breach Science Publishers
Joshi, R. & Lohita, R (2000 ). Properties of Fly Ash Cement (Advances in Concrete Technology).
King, B. (2005). Making Better Concrete: Guidelines to using Fly Ash for Higher Quality, Eco-friendly Structures. Green Building Press
Malhotra, V. & Moltra (2008). High-performance, High-volume Fly Ash Concrete for Building Sustainable and Durable Structures
Malhotra, V. & Ramezanianpour, A.(1994), Fly Ash in Concrete
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