(CPC) Material and Testing Laboratory MANUAL

General Laboratory Instructions

i

General Instruction for Laboratory Report

ii

Experiment No. 1

Inspection of Laboratory Testing

2

Experiment No. 2

Reducing Reducing Field Sample of Aggregates

3

Experiment No. 3

Sieve Analysis of Coarse and Fine Aggregates

5

Experiment No. 4

Specific Gravity and Absorption

10

Experiment No. 5

Determination of Unit Weight (Bulk Density) of Coarse Aggregate

15

Experiment No. 6

Surface Moisture of Fine and Coarse Aggregate

19

Experiment No. 7

Fineness of Cement

22

Experiment No. 8

Normal Consistency of Portland Cement

24

Experiment No. 9

Slump Test of Portland Cement Concrete

26

Experiment No. 10

Time of Setting of Hydraulic Cement by Vicat Needle

28

Experiment No. 11

Making and Curing Concrete Test Specimen in the Laboratory

31

Experiment No. 12

Compressive Strength of Cylindrical Concrete Specimen

34

Experiment No. 13

Splitting Tensile Strength of Cylindrical Concrete Specimen

36

Experiment No. 14

Flexural Strength of Concrete

38

Experiment No. 15

Nondestructive Test of Concrete

40

Experiment No. 16

Determination of Compressive Strength of Concrete Hollow Blocks

42

Experiment No. 17

Moisture Content of Wood

44

Experiment No. 18

Compression Test of Wood Parallel to the Grain

46

Experiment No. 19

Static bending of Wood

47

Experiment No. 20

Tensile Test Parallel to the Grain of Wood

49

Experiment No. 21

Shear Test Parallel to the Grain of Wood

50

Experiment No. 22

Tensile Strength of Steel Bar

52

Experiment No. 23

Penetration of Bituminous Materials

55

GENERAL LABORATORY INSTRUCTIONS LABORATORY MANUALS This manual has been prepared to present the standardized test procedures for checking materials in conformance with the American Society for Testing Materials. This manual describes the test procedures that are currently in use in the Construction Materials and Testing Laboratory. Please read the appropriate materials in the laboratory manuals carefully before attending the Laboratory. Data sheet are in the appendix of this document or will be provided during Laboratory class.

OBJECTIVE The objective of this manual is to acquaint the student with some physical and mechanical properties of selected construction materials and standard methods to be used to evaluate these properties selected construction materials and standard methods to be used to evaluate these properties. A secondary objective is to develop the students’ proficiency in pr eparing an engineering report. The report is to resemble professional engineering reports as much as possible. Grammar, efficient communication, and result will weigh heavily in the final grade.

FIELD TRIPS Field trips are considered as an inspection visit. The observations of the field trip will be included in the appendix of the report. They should observed the general operation, quality control and other factors that may affect the facility’s ability to meet the requirements of the construction contract.

THE REPORT All reports are to be written in the third person; for example, “the test was conducted,” “not we conducted the test”. Each student is expected to come up with fictitious company name and logo. Reports are to apply to the hypothetical project scenario given in this manual. Report must be typed (excluding raw data sheet), and all figures and tables must be computer generated unless otherwise stated. Bind the material neatly. NO BULKY NOTEBOOKS! Points will be deducted for multiple and sloppy stapling. You are encouraged to work together in preparing the reports. However, the report must be your individual effort. If the grader discovers identical charts, tables and discussion between reports he/she can only assume someone did not do their own work. Reproducing reports from past electronic files is prohibited. In other words, zeros will be assigned to reports that give any indication of being duplicated or copied from previous lab reports or another team’s report. LABORATORY TEST The construction Materials and testing course provides credit for three hours of lecture and three hours of laboratory work per week. The laboratory testing has been arranged so that each test may be performed well within the three-hour period.

GENERAL LABORATORY INSTRUCTIONS LABORATORY MANUALS This manual has been prepared to present the standardized test procedures for checking materials in conformance with the American Society for Testing Materials. This manual describes the test procedures that are currently in use in the Construction Materials and Testing Laboratory. Please read the appropriate materials in the laboratory manuals carefully before attending the Laboratory. Data sheet are in the appendix of this document or will be provided during Laboratory class.

OBJECTIVE The objective of this manual is to acquaint the student with some physical and mechanical properties of selected construction materials and standard methods to be used to evaluate these properties selected construction materials and standard methods to be used to evaluate these properties. A secondary objective is to develop the students’ proficiency in pr eparing an engineering report. The report is to resemble professional engineering reports as much as possible. Grammar, efficient communication, and result will weigh heavily in the final grade.

FIELD TRIPS Field trips are considered as an inspection visit. The observations of the field trip will be included in the appendix of the report. They should observed the general operation, quality control and other factors that may affect the facility’s ability to meet the requirements of the construction contract.

THE REPORT All reports are to be written in the third person; for example, “the test was conducted,” “not we conducted the test”. Each student is expected to come up with fictitious company name and logo. Reports are to apply to the hypothetical project scenario given in this manual. Report must be typed (excluding raw data sheet), and all figures and tables must be computer generated unless otherwise stated. Bind the material neatly. NO BULKY NOTEBOOKS! Points will be deducted for multiple and sloppy stapling. You are encouraged to work together in preparing the reports. However, the report must be your individual effort. If the grader discovers identical charts, tables and discussion between reports he/she can only assume someone did not do their own work. Reproducing reports from past electronic files is prohibited. In other words, zeros will be assigned to reports that give any indication of being duplicated or copied from previous lab reports or another team’s report. LABORATORY TEST The construction Materials and testing course provides credit for three hours of lecture and three hours of laboratory work per week. The laboratory testing has been arranged so that each test may be performed well within the three-hour period.

Each laboratory will consist of three parts. These are: I. II. III.

A short briefing on the test which is to be performed. The actual laboratory testing. This will be done in groups of three or four students. In some cases, this may be a demonstration by the instructor. The reduction of rough data. Once the testing is complete each group has secured its own data, the data will be reduced and all necessary computations will be made. Each student will secure a copy of all data and calculations before leaving the laboratory room.

In general, the laboratory report will be submitted one week after each laboratory is performed. General notes on the laboratory reports are given on the following page. Specific instruction will be given for each test. Most of the experiments require some preparation that must be done before coming to class. Completing this reading and/or calculation will prevent needless delay, mistakes, and wasted effort during the laboratory period. During the laboratory period reasonable care should be exercised to prevent damage to equipment and personnel. The equipment in the laboratory is for your use and most of it is quite rugged and not easily damaged; however, if in doubt concerning the operation of the equipment, ask the instructor. An essential element of good laboratory practice is maintaining a clean and orderly laboratory. It will be the responsibility of each group to clean its own equipment and area where their laboratory work is performed. All equipment will be returned to its proper place. One group will be responsible each week for the over-all clean up. The clean-up group will see to it that all equipment is in its proper place. This group will check out with instructor each week. Some of the test will require that someone will check on the test on the day following the laboratory period. The group may delegate one person to do this. However, each group will be responsible for securing any data obtained.

GENERAL INSTRUCTION FOR LABORATORY REPORT The report is to be written in the style of a professional engineering report such as to be submitted by a material-testing laboratory to a construction company or an engineering firm. The report should look like engineering documents. It is recommended that they be neatly typed. The instructor and this manual will provide specific instructions for laboratory reports for each test. The following are the components of formal report: 1. The Title Page/Cover Page

The first page of the report is the title page or a cover page. This page identifies the test to be performed. It shows course number and the laboratory section number, name of person submitting the report, party number, name of persons in your party, and date of submission (date actually submitted, not the date due). 2. Table of Contents

The table of contents is used to facilitate the grading of the reports, and will be used to record the points awarded for each category. The table of contents should include page numbers and the report pages should include computer generated page numbers. Chart and table titles and numbers should also be shown in the table of contents. 3. Introduction

Brief statement as to what you are attempting to accomplish by performing the test. State the significance (usefulness) of the test. 4. Procedure

This section identifies materials, specimen, testing apparatus, and testing procedure. 5. Test Result

This section will contain those facts or answer that you obtained in your experiment, either direct measurements or calculations based on measurement. The section should also include some text referring to tables and charts. This section should also include some text referring to tables and charts. This section may also include a brief statement of the method and materials used to obtain the results. The appropriate standard or test method should be cited on this section. Each table or graph should be self-explanatory-to include suitable title, use a legend or data points and curves. 6. Discussion of Results

In this section the writer provides the foundation upon which his/her conclusion will rest. This acceptance or rejection of the conclusion by the reader will depend largely on discussion of results. Under this heading the writer will comment upon the validity of the results and make comparison with typical values for the measures parameters.

Remember “the acceptance and rejection of the conclusions drawn in the report is directly related to the skill of the reporter in providing an accurate and convincing discussion of the reasoning upon which the conclusions are based.” Give reasons for discrepancies if serious difference appears to exist. Mention limitation of test. 7. Conclusion and Recommendation

It is a brief statement presenting a personal analysis of the results. Conclusions must be reported by, but do not include, the actual results. Statement about the reasonableness of the results should be included. Apply conclusions and recommendations to the fictitious objective given at the beginning of each experiment or to a project scenario created by the student. 8. Appendices

This section includes laboratory data, calculation and data sheets.

RAW DATA AND ADDITIONAL INFORMATION

Inspection:

This section should describe the findings of the inspection visit and the comment on the company’s quality control and ability to meet the specifications and requirements of the contract.

Data Form:

Include the raw data recorded on the forms during the laboratory test. Your laboratory data usually be taken on the forms provided. Do not erase errors. Line them out. It is neither necessary nor desirable to copy data on to clean data sheets for the sake of neatness, since the important results have been provided in the test result section. Also include computer spreadsheets or other information that should not be in the body of the report.

References:

Include a list of all references used, including any software (excluding word processing or spreadsheets). Include consolation with the laboratory Consultants, Instructor, or Professor. Make sure each reference is complete. The reference section of this document should be used as a guide. If the reference is to certain page numbers, include this information. If you referred to a laboratory report prepared in previous term by another student, this should be the referenced as well. Reference to a previous laboratory report is acceptable; however, plagiarism and other inappropriate uses of those old reports w ill be considered a violation of the Honor of Conduct.

PART I. AGGREGATES Mineral aggregate comprises the relatively inert filler materials in Portland Cement Concrete and in asphalt concrete. However, in as much as the aggregate usually occupies about 70 to 80 percent of the volume of the mass of concrete, its selection and proportioning should be given careful attention in order to control the quality of the mixtures. The principal qualifications of aggregate for concrete are numerous. In this manual, the testing methods for determining some of the properties of aggregate that could affect the mix design some of the properties of aggregate that could affect the mix design for Portland Cement Concrete will be presented. They are: 1) Reducing Field Samples of Aggregate to testing Size (ASTM 702-98, C 330-89, D 75, AASHTO T 248) 2) Sieve Analysis (ASTM C 136, C 136-76, C 139-95a, D 702, AASHTO 27-74) 3) Unit Weight (ASTM C 29/C 29 M-91a, C 29, D 75, AASHTO 19-74) 4) Specific Gravity and Absorption (ASTM C 127, C 128, AASHTO 85 -74) These four tests will be performed in two laboratory periods. Reducing Field Samples of Aggregate to Testing Size and Sieve Analysis will be conducted in period and the Unit Weight and Specific Gravity and Absorption test will conducted in another period or on discretion of t he Instructor. Aggregate generally occupy 70 to 80 percent of concrete and therefore have significant effect on its properties. Strength of concrete and mix designs is independent of the composition of aggregate, but durability may be affected. Aggregate are classified based on specific gravity as heavyweight, normal-weight and lightweight. The normal weight of the aggregate make-ups about 90 percent of concrete used in the construction. Shape and texture affect the workability of fresh concrete. The ideal aggregates would be spherical and smooth allowing good mixing and decreasing intersection between particles. Natural sands are close to its shapes. However, crushed stone is more angular and requires more paste to coat the increased surface area. Long, flat aggregate should be avoided due to increase intersection with other particles and the tendency toward aggregate during handling. Shape and texture of coarse aggregate affect the strength of the concrete mix; increased surface area provides more opportunity for bonding and increases strength. However, excessive area in aggregate can lead to internal stress concentration and potential bond failure. Grading of aggregate size distribution is a major characteristic in concrete mix design. Cement is the most expensive material in concrete. Therefore, by minimizing the amount of cement, the cost can be reduced. Aggregate can contain, water, internal, based on porosity, and external, based on surface moisture. This gives the aggregate the ability to absorb water. This effectively reduces the amount of water available for hydration, or conversely, if the aggregate is very wet, adds excess water to a cement mix.

Experiment No. 1:

INSPECTION OF LABORATORY TESTING

Objective:

To let the student become acquainted with material testing laboratory, the equipment’s available, and course requirement. Preparatory Reading:

Apps. A, B, and C (ASTME 380)

Procedure:

1. Under the guidance of an instructor and staff member, visit the laboratory and notice where the general equipment is located. 2. Ask to be instructed in the operation of the Universal Testing Machine. 3. Make a list of the major types of equipment available. Note the units of calibration and the dial division. Report:

Write an informal report that includes: 1. A guide to the laboratory with the major features indicated on a sketch. 2. A brief description of each major testing machine. This should include appropriate factor necessary to convert from the calibration units to SI units. 3. An assessment on the role of the course in your education. 4. Draw the floor plan of the testing laboratory on the space below.

Experiment No. 2:

REDUCING FIELD SAMPLE OF AGGREGATE

Discussion:

These methods cover the reduction of field samples to testing size employing techniques that are intended to minimize variation in measured characteristics between the test samples selected and the field sample. Specifications for aggregate require sampling portion of the material for testing. Other factors being equal, larger samples will tend to be more representative of the total supply. These methods provide for reducing the large sample obtained in the field to a convenient size. This is for the purpose of conducting a number of tests to describe the material and measure its quality in manner that the smaller portion is most likely to be a representation of the field sample and thus the total supply. The individual test methods provide for minimum weights of material to be tested. Objective:

To learn and understand the correct method of obtaining sample aggregate for mechanical analysis.

Referenced Documents:

ASTM (C 702 – 98, C 33, D 75, C 330 – 89) AASHTO T 248

Selection of Method:

1. Fine Aggregate  – Filed sample of fine aggregate that are drier than the saturated surfacedry condition shall be reduced in size by a mechanical splitter according to Method A. Field sample having free moisture on the particle surface may be reduced in sizes by quartering method according to Method B. 1.1 If the use of Method B is desired and the field sample does not have free moisture on the particle surfaces, the sample may be moistened to achieve this condition, thoroughly mixed and then the sample reduction performed. 1.2 If the use of Method A is desired and the field sample has free moisture on the particle surfaces, the entire field sample may be dried to at least surface-dry condition using the temperature that do not exceed those specified for any of the test contemplated and then the sample reduction performed. 2. Coarse Aggregates and Mixture of Coarse and Fine Aggregates – Reduce the sample using a mechanical splitter in accordance with Method A (preferred method) or by a quartering method in accordance with Method B. Apparatus and Materials:

1. Representative sample of aggregate 2. Spade 3. Container 4. Sample Splitter Procedure:

Method A  – Mechanical Splitter

1. Check moisture condition of aggregate – If the sample has free moisture on the particle surface the entire sample must be dried to at least the SSD condition prior to reduction by splitter. 2. Check sample splitter chute opening. (Their number and width relative to maximum size of aggregate) 3. Place the sample in the hopper or pan and uniformly distribute it from edge to edge, so that when it is introduced into the chutes, approximate and equal amounts will flow through each chute. 4. The rate of which the sample is introduced shall be of such as allow free flowing through the chutes into the receptacle below. 5. Reintroduce the portion of the sample in one of the receptacles as many times as necessary to reduce to specified size for the intended test. 6. The portion of the material collected in the other receptacle may be reserved for reduction in size for other test. Method B  – Quartering

1. Place the sample on a hard, clean, level surface where there will neither loss of material nor the accidental addition of foreign material. 2. Mix the material thoroughly by turning the entire sample over three times. With the last turning, shovel the entire sample into a conical pile by depositing each shovel on top of the preceding one. 3. Carefully flatten the conical pile to a uniform thickness and diameter, by pressing down the apex with a shovel or other device so that each quarter sector of the resulting pile will contain the material originally in it. The diameter should be approximately four to eight times the thickness. 4. Divide the flattened mass approximately into four equal part quarters with a shovel, trowel or other suitable device and remove to diagonally opposite quarters, including all fine materials and brush the cleared spaces clean. 5. Successively mix and quarter the remaining material until the sample is reduced to the desired size.

Experiment No. 3:

Sieve Analysis of Coarse and Fine Aggregate

Discussion:

The sieve analysis is used to determine the particle size distribution or gradation of an aggregate. A suitable gradation of an aggregate in a concrete mix is desirable in order to secure workability of concrete mix and economy in the use of cement. For asphalt concrete, suitable gradation will not only affect the workability of the mixture and economy in the use of asphalt, but will affect significantly the strength and other important properties.

The sieve analysis of an aggregate is performed by “sifting” the aggregate through a series of sieves nested in order, with smallest opening at the bottom. These sieves have square openi ngs and are usually constructed of wire mesh. In the testing of concrete aggregates, there is generally employed a series of sieves in which any sieves in the series has twice the clear opening of the next smaller size in the series. The U.S. Standard Sieve Series and the clear opening of the sieve are given below: U.S Standard Sieve Size No.100 No.50 No.30 No.16 No. 8 No. 4 3/8”  ½”(half size)  ¾”  1 in. (half size) 1 ½ in.

Clear Opening (in.) 0.0059 0.0117 0.0232 0.0469 0.0937 0.187 0.375 0.500 0.750 1.000 1.500

Sometimes closer sizing than is given by the standard series is desired, in which case “half size or odd” sizes are employed; the ½ in. and 1 in. shown are half size. Coarse aggregate is usually considered to be larger and fine aggregates smaller than #4 sieve. Thus all series need to be used physically in the nest but are still considered in the analysis. For example, sieve larger than 3/8 in. is not used for the sand and sieve smaller than No. 8 are seldom used for gravel. The fineness modulus is an index number, which is roughly proportional to the average size of the particles in a given aggregate. It is computed by adding the cumulative percentages coarser than each of certain sieves and dividing by 100. (Note: Even though some material may be retained on the pan, it is not considered a sieve and does not enter into computations for fineness modulus. In addition, if sieves other than those standard sieve listed above are used, they are not used, they are not used directly in the

computations and any material retained on such sieves should be considered as being retained on the next smaller sieve of the series used in the computations e.g. any material retained on a 1 in. sieve would be added to the ¾ in. sieve for purposes of fineness modulus computation. However, the amount and percentage of the 1 in. material would appear in the tabular listing in the sieve analysis. The following illustration the calculations of the fineness modulus: Sieve No.

Weight Retained

4 8 10 16 30 50 80 100 Pan

30 40 30 30 35 45 40 50 10

Cumulative Retained 30 70 100 130 165 210 250 300 310

Weight % Cumulative Retained 9.7 22.6 --* 42.0 53.3 67.8 --* 96.8 100

Fineness modulus of sand = 9.7 + 22.6 + 42.0 + 53.3 + 67.8 + 96.8 = 2.92 100

“odd” sieves not used directly in fineness modulus calculations. An interpretation of the fitness modulus might be that it represents the (weighted) average of the group upon which the material is retained, NO. 100 being the first, NO. 50 second, etc. thus for the sand with FM of 3.00, sieve NO.30 (the third sieve) would be the average sieve size upon which the aggregate is retained. Objective: to determine the particle size distribution of fine and coarse aggregate by sieving. Referenced Documents:

ASTM (136-96a, C 702, e 11, D 75) AASHTO (T 27-91, T 11- 65 )

Apparatus:

1. Balance, accurate to 0.1 g 2. Set of sieves with pan and cover 3. Mechanical sieve shaker ( optional) 4. Brush 5. Oven

Procedure:

1. Obtain the representative sample by quartering or by the use of sample splitter. The sample to the tested should be the approximate of fine aggregate and about 10  – 12 kilograms of coarse aggregate. 2. Dry the sample to constant temperature in the oven at a temperature 110±5 C( 230 ±41 F) °

°

3. Assemble the sieves in order of decreasing size of opening from top to bottom and place sample on the top of the sieve and cover it with the lid. a. For coarse aggregate: 1”, ¾’’,1/2’’, 3/8’’, #4 , #8, pan b. For fine aggregate: 3/8’’, #4, #8, # 30, # 50,#100,pan 4. Agitate the sieve by hand or by mechanical shaker for five minutes or for a sufficient period. 5. Limit the quantity of material on a given sieve so that all the particles have opportunity to reach sieve openings a number of times during the sieving operations. For the sieve with openings smaller than No. 4 (4.75 mm), the weight retained on any sieve at the completion 2 of the sieving operation shall not exceed 6 k/m of sieving surface. For the sieve with 2 openings No. 4 (4.75 mm) and larger, the weight in kg/m  of the sieving surface shall not exceed the product of 2.5 x (sieve opening in mm). In no case shall the weight be so great as to cause permanent deformation of the sieve cloth. 6. Continue sieving for sufficient period in such a manner that, after completion, not more than 0.5 percent by weight of the total sample passes any sieve during one (1) minute of continuous hand sieving. 7. Weigh the material that is retained on each sieve, including the weight retained in the pan, and record in the data sheet. The total weight of the material after sieving should check closely with original sample placed on the sieve. Of the sum of these weights is not within 1 percent (0.3 for ASTM requirement) of the original sample, the procedure should be repeated. 8. Compute the cumulative percent retained on, and percent passing each sieve. 9. Plot the gradation curves for the coarse and the fine aggregates from the experiment on the graph provided. Plot the specified gradation curves for coarse and fine aggregates (to be specified by the laboratory instructor). Plot the combine-grading curve using the 40% aggregate and 60% fine aggregate. 10. Compute the Fineness Modulus for fine and coarse aggregate.

CONSTRUCTION MATERIALS AND TESTING LABORATORY CIVIL ENGINEERING DEPARTMENT

SIEVE ANALYSIS DATA SHEET Name:__________________________________________

Group No.:______________

COARSE AGGREGATE Initial Weight:____________________

Sieve No.

Weight Retained

Cum. Weight Retained

Cum. Percent Retained

Percent Passing

FINE AGGREGATE Initial Weight:_________________

Sieve No.

Weight Retained

Cum. Weight Retained

Cum. Percent Retained

Percent Passing

CONSTRUCTION MATERIALS AND TESTING LABORATORY CIVIL ENGINEERING DEPARTMENT

SIEVE ANALYSIS Name:___________________________________________ Group No.:____________________

100

90

80

70    G    N    I 60    S    S    A    P    T    N    E 50    C    R    E    P

40

30

20

Date:________________

10 220

210

100

50

30

16

6

4

3/8”

¾”

1”

SIEVE SIZE

Experiment No. 4:

Specific Gravity and Absorption

Discussion:

Basically, specific gravity is the ratio of the weight of a given volume of material to the weight of an equal volume of water. However, there are several variations on this definition depending upon the material and the purposes for which the value of specific gravity are to be use. In concrete work, the term specific gravity customary refers to the density of the individual particles, not to the aggregated mass as a whole. The most common definition of specific gravity in concrete aggregate is based upon the bulk volume of the individual aggregate in saturated surfacedry condition (SSD). The bulk (oven-dry) specific gravity and the apparent specific gravity are use to a lesser degree. Solid unit weight in pounds per cubic foot (pcf) of an aggregate is customarily defined as the specific gravity times 62.4 pcf. The absorption capacity is determined by finding the weight of an aggregate under SSD condition and oven-dry condition. The difference of weights expressed as a percentage of the oven-dry sample weight is the absorption capacity. Coarse aggregate are considered to be saturated surface-dry when they have wiped free of visible moisture films with cloth after the aggregates have been soaked in a water for a long period of time (over 24 hours). The saturateddry condition of fine aggregate is usually taken as that at which a previously wet sample just became free-flowing. Objective:

Test method covers the determination of the specific gravity and absorption of coarse and fine aggregate.

Referenced Documents:

ASTM (C 127, C 136, C 70, C 702) AASHTO T 85

Apparatus:

For Coarse Aggregate: 1. 2. 3. 4. 5.

Balance, sensitive to 0.01 lb or gram Wire mesh basket Drying oven 3/6” sieve Water tank

For Fine Aggregate: 1. 2. 3. 4.

Balance, sensitive to 0.01 lb or gram 500 ml Chapman Flask Dryer Drying Oven

Preparation of Sample  (for Coarse Aggregate)

1. Thoroughly mixed the sample aggregate and reduce it to the approximate quantity needed using quartering or mechanical shaker method 2. Reject all materials passing at 4.75 mm (No. 4) sieve sieving and thoroughly washing to remove dust or other coatings from the surface. 3. The minimum weight of test sample to be used is given below: Nominal Maximum Size Mm (in.) 12.5 (1/2) or less 19.0 (3/4) 25.0 (1) 37.5 (1½) 50 (2) 63 (2½) 75 (3) 90 (3½) 100 (4) 112 (4½) 125 (5) 150 (6)

Maximum Weight of Test Sample Kg (lb.) 2 (4.4) 3 (6.6) 4 (8.8) 5(11) 8 (18) 12 (26) 18 (40) 25 (55) 40 (22) 50 (110) 75 (165) 125 (276)

Procedure:

For Coarse Aggregate



1. Dry the test sample to constant weight at a temperature of 110 ± 5ºC (230 9ºF). 2. Cool in air at room temperature 1 to 3 hours, or until the aggregate has cooled to a temperature that is comfortable to handle (approximately 50ºC) and weigh. 3. Soak aggregate under water for 24 ± 4 hours. 4. Obtain approximately 5 kg of saturated coarse agg regate (retained on 3/8” sieve preferably.

5. Towel the aggregate to a saturated surface-dry condition (SSD). A moving steam may be used to assist drying operation. Take care to avoid evaporation of water from aggregate pores during the surface-drying operation. 6. Measure SSD weight (B) of aggregate in air to the nearest 1 gm. Do this quickly to prevent evaporation.

7. Place the sample in the wire mesh basket, and determine its weight in water (C) at 23 ± 1.7ºC (73.4 ± 3ºF). Take care to remove all entrapped air before weighing by shaking the container while immersed. Be sure to subtract the submerged weight of the basket from the total. 8. Place wet aggregate in oven, and dry to constant weight at temperature of 110 ± 5ºC (230 ± 9ºF) (leave the aggregate in oven overnight). Cool the aggregate in air at room temperature 1 to 3 hours, or until the aggregate has cooled to a temperature that is comfortable to handle (approximately 50ºC) and weigh (A). 9. From the above data (i.e., A, B, and C) calculate the three types of specific gravity and absorption as defined below: (1) Bulk Specific Gravity (Dry) = ___A___ B – C

(2) Bulk Specific Gravity (SSD) =

B___ B – C

(3) Apparent Specific Gravity =

A___ A – C

(a) Absorption =

B – A___ x 100 A

A = weight of oven-dry test sample, gm B = weight of saturated surface-dry sample in air, gm C = weight of test sample in water, gm Procedure:

For Fine Aggregate

1. Obtain approximately approximately 4 kg air-dry fine aggregate (all groups working together). 2. Bring fine aggregate to SSD condition as explained by the instructor. 3. Each group takes approximately 500 gm of the SSD aggregate. Record exact weight of SSD sample (D). 4. Fill Chapman Flask to 450 ml marks and record weight of water and flask in grams (B). The water temperature should be about 23 ± 1.5ºC (73 ± 3ºC). 5. Empty water in flask to about 200 ml marks and adds SSD aggregate to flask. Fill flask to almost 450-ml mark with additional water. 6. “Roll” flask on top surface to eliminate air bubbles. Then fill the flask with water up to 450-ml. record total weight (in gm) of flask plus the water plus aggregate (C). 7. Pour entire contents of flask into pan and place in oven. Additional tap water may be used as necessary to wash all aggregate out of the flask. Return after 24 hours or as long as it takes for the aggregate to dry and record weight of oven-dry aggregates (A). 8. From the date above, calculate specific gravities and absorption absorption defined below:

(1) Apparent Specific Gravity =

A____ B + A – C

(2) Bulk Specific Gravity =

A____ B + D – C

(3) Bulk Specific Gravity (SSD) =

(4) Absorption =

D____ B + D – C

D – A____ x 100% A

CONSTRUCTION MATERIALS AND TESTING LABORATORY DEPARTMENT OF CIVIL ENGINEERING SPECIFIC GRAVITY AND ABSORPTION DATA SHEET FINE AGGREGATE ITEM SSD Weight in Air (D) Weight of Pyc. + Water (B) Weight of Pyc. + Water + Sample (C) Oven Dry Weight (A)

WEIGHT

COARSE AGGREGATE ITEM SSD Weight in Air (B) Weight in Water (C) Oven Dry Weight (A)

WEIGHT

RESULTS COARSE Apparent Specific Gravity Bulk Specific Gravity (Dry) Bulk Specific Gravity (SSD) Absorption

FINE

Experiment No. 5:

Determination of Unit Weight (Bulk Density) of Coarse Aggregate

Discussion

The test covers the determination of bulk density (“unit weight”) of aggregate in a compacted or loose condition, and calculated voids between particles in fine, coarse, or mixed aggregates based on the same determination. Unit weight or bulk density is the weight of a given volume of material. Basically, unit weight is measured by filling a container of known volume with a material and weighing it. The degree of moisture and compaction will affect the unit weight. Therefore, The ASTM has set standard oven-dry moisture content and a rodding method or compaction. The maximum unit weight of a blend of two aggregates is about 40% fine aggregate by weight. Therefore, this is the most economical concrete aggregate since it will require the least amount of cement. The bulk density of aggregate is a mass of a unit volume of bulk aggregate material, in which the volume includes the volume of the individual particles and the volume of voids between the particles and is expressed in lb/ft³ (kg/m³). Unit weight is a weight (mass) per unit volume. Objective: To determine the unit weight (bulk density) values that is necessary for use for several methods of selecting proportions for concrete mixtures. Referenced Documents:

ASTM (C 29, C 29M – 97, C 127, C 702, C 136 AASHTO T 11)

Apparatus:

1. Balance, sensitive to 0.1 lb or 0.05 kg 2. Tamping rod, 5/8” (1 6 mm) diameter 3. Volume measure Procedure:

1. Obtain a representative sample of air-dry thoroughly mixed coarse aggregate and reduce the sample by quartering method. 2. Fill the measure one-third full and level the surface with fingers. 3. Rod or tamp the layer 25 strokes of the tamping rod evenly distributed over the surface. 4. Fill the measure to two-thirds full and rod 25 times without penetrating the previous layer.

5. Fill the measure to overflowing and 25 times. Level the surface with fingers or the rod such that any slight projections of larger pieces of aggregate approximately balance the larger voids in the surface below the top of the measure. Do not compress the aggregate. 6. Determine the weight (or mass) to the nearest 0.1 lb (0.05kg) 7. Calculate the unit weight Calculation:

CONSTRUCTION MATERIALS AND TESTING LABORATORY DEPARTMENT OF CILVIL ENGINEERING COLEGIO DE LA PURISIMA CONCEPCION

DATA SHEET

Name: _________________________________________________

Group No.: ________

Date: __________________

Aggregate: Maximum Size: Nom. Grad: Source: ITEM Total weight, lb (kg) Measured Weight, lb (kg) Weight of Aggregate, lb (kg) Measure Volume, ft³ (m³) Unit Weight, lb/ft³ (kg/m³) % Difference from Average

Trial 1

Trial 2

Trial 3

Calculation: UW = (Wt – Wm) V UW = Unit Weight (Bulk Density), lb. ft³ (kg/m³) Wt = weight of aggregate plus measure

Trial 4

Wm = weight of calibrated measure

TABLE 1 DIMENSIONS OF MEASURES (U.S CUSTOMARY SYSTEM) Capacity (ft³)

1/10 1/3 ½ 1

Inside Diameter (mm) 6.0 ± 0.1 8.0 ± 0.1 10.0 ± 0.1 14.0 ± 0.1

Inside Height (mm)

6.1 ± 0.1 11.5 ± 0.1 11.0 ± 0.1 11.2 ± 0.1

Minimum Thickness of Metal (in.) Bottom 0.20 0.20 0.20 0.20

Max. Nominal Size of Agg.ᵇ (in.) Wall 0.10 0.10 0.12 0.12

½ 1 1½ 4

TABLE 2 DIMENSIONS OF MEASURES (METRIC SYSTEM) Capacity (liters)

3 10 15 30

Inside Diameter (mm) 155 ± 2 205 ± 2 255 ± 2 355 ± 2

Inside Height (mm) 160 ± 2 205 ± 2 295 ± 2 305 ±2

Minimum Thickness of Metal (in.) Bottom 5.0 5.0 5.0 5.0

Max. Nominal Size of Agg.ᵇ (mm) Wall 2.5 2.5 3.0 3.0

12.5 25.0 37.5 100.0

TABLE 3 UNIT WEIGHT OF WATER Temperature °F 60 65 70 (73.4) 75 80

lb/ft³

Kg/m³

°C 15.6 18.3 21.1 (23.0) 23.9 26.7

62.366 62.366 62.301 (62.274) 62.261 62.216

999.01 998.53 997.97 (997.53) 997.32 996.60

85

29.4

62.166

995.80

*The Indicated size of container may be used to test aggregate of a maximum nominal size equal to or smaller than that listed. *Based on sieves with square openings. Experiment No. 6:

Surface Moisture of fine and coarse aggregate

Discussion

This test method describes a rapid procedure in the field for determining the percentage of surface moisture in the both fine and coarse aggregate by displacement in water or by oven dry method. Surface moisture is defined as moisture in excess of that contained by the aggregate when in the standard surface dried-condition. This is the value desired in correcting the batch masses for the Portland cement concrete. The accuracy of the methods depends upon the accurate information on the bulk specific gravity of the material in a saturated surface dry condition. Objective:

To determine the percentage of surface moisture in both fine and coarse aggregate.

Referenced Documents:

ASTM (C 566-96, C 127, C 128, C, 125)

Apparatus:

1. Balance, sensitive to 0.1 gm 2. Sample container 3. Stirrer or spoon or spatula 4. Flash or pycnometer 5. Small rubber syringe or medicine dropper Procedure:

Methods A – Pycnometer or Flash Method 1. Obtain a representative sample or specimen of fine and coarse aggregate. 2. Fill the Pycnometer with water at temperature of between 18°C  – 29°C (65°F - 85°F) to the mark taking care not to trap air bubbles. The final increments of water shall be added using a syringe or medicine dropper. 3. Thoroughly wipe any excess water from the outside of the container and determine the weight (mass) to the nearest 0.1 gm. 4. Empty the container and partially fill with enough water to cover the specimen when introduced.

5. Introduce the weighted specimen into the container and remove the entrapped air by using a vacuum or by stirring and carefully rolling or shaking the container unit no significant air bubbles rise to the surface. 6. Completely fill the container with water to the original mark, wipe off any excess water and determine the weight (mass) to the nearest 0.1 gm.

Calculation:

        Where: C = weight (mass) of pycnometer filled with water. W = weight (mass) of pycnometer, specimen and water V = weight (mass) of displaced water = C + S - W S = weight (mass) of specimen D = weight (mass) of specimen divided by the bulk specific gravity of Aggregate in saturated surface dry condition = S/G. G = bulk specific gravity of aggregate in saturated dry condition Method B – Oven D 1. Obtain a representative sample of aggregate. For f ine aggregate, obtain a specimen with a weight (mass) of approximately 500 gm. For coarse aggregate, obtain a specimen of approximately 1000 gm. 2. Identify and weigh sample container. 3. Put the sample aggregate into a container. 4. Weigh the container with sample aggregate to the nearest 0.1 gm. 5. Dry the sample to a constant weight (mass) at 110°C±5°C (230°F). 6. When dry weigh to the nearest 0.1 gm. And record the oven dry. Calculation:

1. Total percentage of moisture in an oven dry basis:

              

Wet Wt = original weight (mass) of aggregate Dry Wt = oven dry weight (mass) 0f aggregate 2. Calculate the percent surface (free) moisture: % Surface moisture = (% Moisture, Oven Dry Basis) (% Absorption, from Mix Design)

PART II. PORTLAND CAMENT CONCRETE Concrete is a very important material at construction, composed essentially of Portland cement, water and mineral aggregates. The mixture of these ingredients is plastic when mixed and placed, and gradually hardens and develops strength with age. The quality of concrete may be expressed in terms of certain basic properties required in plastic and hardened concrete. These properties are common to all concrete, regardless of its use. The difference in concrete requirements for various construction and structural uses are in degree, not in kind. Thus, the same principle in the mix design, placing and cutting govern the production of all concrete. In general, there are four basic steps in the production of concrete, each of which has an important effect upon the quality of the concrete. The ste ps are: 1) Mix Design – Quality of material and mix proportion 2) Production – Measuring and mixing materials 3) Handling and Placing  – Workability of concrete, placing and finishing 4) Curing – Methods, time and temperature of curing To maintain quality control of Portland cement, a set of ASTM specifications for both chemical and

physical requirements have been established. A series of “standards” test have been developed to ensure that these specifications are met. However, since results from different test for the same property can vary widely, direct comparison of these tests is difficult. a) Chemical requirements  –  These specifications are not very strict since cements with different chemical compounds can have similar physical behavior. b) Physical requirements  –  These specifications are more important than chemical requirement. The experiment included in this part are aimed toward familiarizing the student with use of a concrete mix design method and laboratory concreting practice, observing the characteristics properties of fresh concrete, and familiarizing with the testing methods for determining the properties of hardened concrete.

Experiment No. 7:

Fineness of Cement

Discussion

The rate of hydration and hydrolysis and the consequent development in cement mortar depends upon the fineness of grinding of cement. To have the same rate of hardening in different brands of cement, the fineness has been standardized. 1. The rate of hydration increase with fineness and leads to high strength and heat generation. 2. Hydration takes place on the cement particle surface. Finer particles will be more completely hydrated 3. Increasing fineness decreases the amount of bleeding bur also requires more water for workability, which can result in an increase in dry shrinkage. 4. High fineness reduces the durable of freeze-lhaw cycles. 5. Increased fineness requires more gypsum to control setting. The most important properties are specific surface of the particles, and particle size distribution. Fineness was originally measured using sieve analysis, but this method is very awkward and really gives no information about the distribution of fine particles. In general, fineness is measured by a single parameter, specific surface area. This parameter is considered the most useful measure of cement fineness even though it does not measure particle distribution. There are two ASTIM test for fineness: 1. Wagner Turbidimeter - measured specific surface area from suspension of the cement in a tall glass container. The test is based on Stroke's Law that states a sphere will obtain a constant velocity under the action of gravity. 2. Blaine air permeability apparatus - This test is based on the relationship between the surface area in porous bed and the rate of the fluid flow ( air ) through the bed. The test is compared to a standard sample determined by the U.S. Bureau of standards. The Blaine method is used more often and is generally 1.8 times larger than the Wagner method. However, in cases of dispute, the Wagner method governs. Objective:

To determine the fineness of Portland cement by sieve analysis.

Referenced Documents:

ASTM 115 - 96a

AASHTO ( T98 - 99, T 192 ) Apparatus:

1. Balance, sensitive to 0.1 gm. 2. Sieve No. 200 3. Container Procedure:

1. Weight accurately 100 gm of cement and place it on No. 200 sieve. 2. Breakdown any air-set lumps in the sample with fingers but do not rub it on the sieve. 3. Sieving is done by a gentle motion of the wrist for fifteen ( 15 ) minutes continuously 4. Weight the residue and should not exceed ten percent ( 10% ) by weight of the cement sample Calculation:

Experiment No. 8:

Normal Consistent of Portland Cement

Discussion

Consistent, one property of the fresh concrete is an important consideration in the securing of workable concrete that can be properly compacted in the forms. Workability is a relative term referring to the comparative ease with which concrete can be placed on a given type of work. The term consistency relates to the state of fluidity of the mix and embraces the range of fluidity the mix and embraces the range of fluidity from the driest to the wettest mixtures. The most common tests to determine consistency: 1. Slump test – is made by measuring the subsidence of a pile of concrete 20mm (12 in.) high, framed in the mold that has the shape of the frustum of a cone. 2. Ball penetration – is made by measuring the settlement of a 150 mm steel ball (weighing 13.6 kg with its handle) into the surface of the concrete. For convenience, various degrees of wetness of a mix may be roughly classified as dry, stiff, medium, wet, or sloppy. Concrete is said to have medium or plastic consistency when it is just wet enough to flow sluggishly- not so dry that is crumbles or so wet that the water or paste runs from the mass. The principal factors affecting consistency are: 1. The relative proportions of cement to aggregate 2. The water content with the mix. 3. The size of the aggregate 4. The shape and the surface characteristics of the aggregate particles. 5. The fineness and type of cement and the kind and amount of admixture. Objective:

To determine the normal consistency of Portland cement Vicat apparatus.

Referenced Documents:

ASTM C 187 -56 AASHTO T 129

Apparatus:

1. Balance, sensitive to 0.1 gm. 2. Vical apparatus 3. Spatula 4. Mixing pan 5. Graduated cylinder, capacity 50 ml to 200 ml Temperature and Humidity: 1. The temperature of the air in vicinity of the mixing slab, the dry cement, molds, and the base plates shall be maintained between 20°C- 27.5°C (68°C- 81.5°F). The temperature of the mixing water shall not vary from 23°C (73.4°F) by more than plus or minus 1.7°C (3°F). 2. The relative humidity of the laboratory shall be not less than 50 percent. Procedure:

1. Weigh accurately 300 gm of neat cement sample and place it on the mixing pan. 2. Mix about 25% of clean water to the cement by means of spatula for about one minute. 3. Mixed it thoroughly with hands for at least one minute. 4. The kneaded paste is formed into a ball and tossed six times from one hand to the other, maintaining the hand about 6 inches apart. 5. The ball is pressed into a conical ring or conical mold completely filling the ring with paste. 6. Sliced off the excess paste at the top of the ring by a single oblique stroke of a sharp edge spatula or trowel and the top smoothed, if necessary, with a few light touches of the toward or spatula. Care shall be taken not to compress the paste. 7. Center paste confined in the ring under the larger end of the rod. 8. The larger end of the rod is brought in contact with the surface of the paste and tightened the screw. 9. Set the movable indicator to zero marks of the scale and tightened the screw. 10. The rod is then quickly released without any jerk and the penetration noted. 11. If the rod penetrates 33 to 35 mm the paste is said to be normal consistency 12. Trial paste shall be made with varying percentage of water until the normal consistency is obtained. Each trial shall be made with fresh cement. The amount of water is expressed as percentage by weight of dry cement usually 30%.

13. The time taken between adding of water to cement and filling of the ring or mold should be between 3 to 5 minutes.

Experiment No. 9:

Slump Test of Portland Cement Concrete

Discussion

The slump test is made by measuring the settlement of a 12 in.(300 mm) high concrete.formed in a mold that has a slope of the frustum of a cone. This method may be used to deetermine the slump of plastic concrete,both in the laboratory and in the field having up coarse aggregate up to 1 1/2 (38mm) in size. This test method is not cosedered applicable to non plastic and noncohesive concrete, nor where there is a considerable amount of coarse aggregate over 2inches in size in concrete. The test spicemen shall be formed in a mold of metal not thinner than No.16 gage and not readily attached by the cement paste and in the form of the lateral surface of the frustsm of a cone with the base of 8inches (205mm) in diameter, the top is 4 inches (102mm) in diameter, and the high 12 inches (307mm). The base and the top shall be open and parallel to each other and the right angles to the axis of the cone.The mold may be constructed either with or without a seam. The tamping rod shall be roond. Straight stell rod 5/8 inches (16 mm) in diameter and approximately 24 inches (615 mm)in length, having one end rounded to hemispherical tip the diameter of which is 5/8 inches. Objectives:

To determine the slump of concrete mixture,both in the laboratory and in the field.

Referenced Documents:

ASTM (C 143-74,C 143M -00,C 172-71) AASHTO (T-23,T-119,T-126)

Apparatus:

1. Slump 2. Spade 3. Container 4. Mixing box 5. Graduated cylinder 6. Meter stick Procedure:

1. Take a representative sample of aggregate; wash so that it will be free from still and clay and dry. 2. Using a proportion of 1:2:4 by weight, equal amount of sand and gravel for a total of 12 kg and place them on the mixing box. Add 2 kg of cement, and water, using water- cement ratio of 0.45, 0.55, 0.65.

Keep precise record of the amount of the materials. It is

convenient to measure the water in the graduated cylinder (1000 ml= 1 kg) Mix them thoroughly. 3. Dampen the mold and place it on the flat, nonabsorbent and the rigid surface. The operator standing on the two foot pieces shall hold it firmly in place during filling. 4. Fill the mold in three years, each layer should be approximately one-third the volume of the mold. 5. Rod each layer 25 strokes with a tamping rod. Uniformly distribute the stroke over the cross-section of each layer by using approximately half the stroke near the perimeter (outer edge) and progressing spirally toward the center. 6. Rod the bottom layer through its depth. 7. Rod the second and the layer each throughout its depth, so that the strokes just penetrate into the underlying layer. 8. In filling and rodding the top layer, heap the concrete above the mold before rodding is started. If the rodding operation results in a subsidence of the concrete below the top edge of the mold add additional concrete to keep excess at all time. 9. After the top layer has been rodded, strike off the surface of the concrete by means of scree ding and rolling motion of the tamping rod. 10. Remove the mold immediately from the concrete by raising it carefully in a vertical motion. Raise the mold a distance of 12 inches (300 mm) in 5 + 2 second by a steady upward lift with no lateral or torsional motion. Complete the entire test from the start of filling through removal of the mold without interruption and complete it within an elapsed time of 2 1/2 minutes. 11. Place the meter stick horizontally across the inverted mold so that the meter stick extends over the slumped concrete. Immediately measure the distance from the bottom of the meter stick to the original center of the top surface of the specimen. 12. If a decided falling away or shearing off of concrete from one side or portion of the mass occurs. Disregard the test and make a new test on another portion of the sample. 13. Record the slump in term of inches (mm) to the nearest 1/4 inches (6mm) of subsidence of the specimen during the test.

Calculation:

Slump= 12 inches -inches of the height after subsidence.

Experiment No. 10:

Time of Settings of Hydraulic Cement by Vicat Needle

Discussion

Cement paste setting time is affected by the number of items including: cement fineness, water-cement ratio, chemical content (especially content) and admixtures. Setting time test are used to characterize how a particular cement paste sets. For construction purposes, the initial set must not be too soon and the final set must not be too late. Additionally setting times can give some indication whether or not cement is undergoing normal hydration. (PCA, 1988). To ensure sufficient time to take place concrete while it remain plastic, a minimum limit is

imposed on the time of “ initial ” set, which may be taken as a condition of the mass when if begins to stiffen appreciably. ASTM specification requires that the initial set should not take place within one hour. Depending on the test used to determine it the initial set usually takes place within two to four hours. To ensure that cement will harden for use, a maximum limit is imposed on the time

of “final” set. ASTM specification requires that the fi nal set occur within 10 hours. With much commercial cement final set occurs within five to eight hours. The condition of initial and final set is determined by penetration of standard needles o rods into a “neat) (straight cement) paste of specified consistency. Both common setting time test, the Vicat needle and the Gillmore needle, define the initial set and final set based on the time at which a needle of particular size and weight either penetrates a cement paste sample to a given depth or fails to penetrate a cement past sample. Time of setting by Vicat needle  – Initial setting occurs when a 1-mm needle penetrates 25 mm into

cement paste. Final set occurs when there is no visible penetration. Time of setting by Gillmore needle  – Initial set occurs when a 113.4 grams Gillmore needle (2.12

mm in diameter) fails to penetrate. Final set occurs when a 453.6 grams. Gillmore needle (1.06 mm in diameter) fails to penetrate. The Vicat needle test is more common and tends to give shorter times than Gillmore needle test. ASTM C 150 Specified Set Times by Test Method Test Method

Set type

Vicat

Initial

Time Specification   45

minutes

Final Gillmore

Objective:

  375

minutes

Initial

 60 minutes

Final

 600 minutes

To determine the time of setting of hydraulic cement by the use of Vicat needle.

Referenced Documents:

ASTM (C191-82 , C 191-04 , C 403/C403M – 99 , C 266) AASHTO (T 131 , T 154)

Apparatus:

1. 2. 3. 4. 5.

Balance, sensitive to 0.1 gm. Vicat needle apparatus Graduated cylinder, 200 ml or 250 ml capacity Trowel or spatula Mixing container

Procedure:

1. Mix 650 gm of cement with the percentage of mixing water required for normal consistency. 2. Quickly form the cement paste into a ball will gloved hands and tossed six times from one hand to another maintaining the hands about 6 inches (152 mm) apart. 3. Press the ball, resting in the palm of the hand, into a larger end of the conical ring held on the other hand completely filling the ring with paste. 4. Remove the excess of the larger end by a single movement of the palm of the hand. 5. Place the large end on a glass plate and slice off the excess paste at the smaller end at the top of the ring by a single oblique stroke of a sharp edged trowel or spatula held at a slight angle with the top of the ring. 6. Smooth the top of the specimen, if necessary, with one or two light touches of the pointed end of the trowel. 7. During the operation of cutting and smoothing, take care not to compress the paste. 8. Place the test specimen in the most closet or moist room immediately after molding and allow it to remain there except when determination of time of setting are being made. The specimen shall remain in the conical mold throughout the test period. 9. Allow the time of setting specimen to remain in the moist cabinet for 30 minutes after molding without being disturbed.

10. Determine the penetration of the 1  – mm needles at this time and every 1.5 minutes thereafter until the penetration of 25 mm or less is obtained. 11. For penetration test, lower the needle of the rod until it rests on the surface of the cement paste. Tighten the setscrew and set indicator at the upper end of the scale. Take an initial reading. Release the rod quickly by releasing the setscrew and allow the needle to settle for 30 seconds and take the reading to determine the penetration. No penetration test shall be made closer than 1/4 in. (6.4 mm) from any previous penetration and no penetration shall be made closer than 3/8 in (9.5 mm) from the inside of the mold. 12. Record the results all penetration tests and, by interpolation determine the time when a penetration of 25 mm is obtained. This is the initial setting time. The final setting time is when the needle does not sink visibly into the paste. WORKSHEET REPORT:

TIME OF SETTING OF HYDRAULIC CEMENT BY VICAT NEEDLE

NAME: ____________________________________ TESTED BY: ________________________ DATE: ____________________________

Specimen No.

Time (second)

Penetration (mm)

Experiment No. 11:

Making and Curing Concrete Test Specimen in the Laboratory

Discussion

This practice covers procedure for making and curing concrete test specimen of concrete in the laboratory under accurate control of materials and test conditions using concrete that can be consolidated by rodding or vibration. The values stated in either in pound units or SI units shall be regarded separately as standards. The SI units are shown in brackets. The values stated in each system are not exact equivalent; therefore, each system shall be used independently of each other. Combining values from two systems may result in non-conformance. This practice provides standardized requirements for preparation of materials, mixing concrete, and making and curing concrete test specimens under laboratory conditions. If the specimen preparation is controlled, the specimen may be used to develop information for following purposes: 1. 2. 3. 4.

Mixture proportioning for concrete project Evaluation of different mixtures and materials Correlation with nondestructive tests Providing specimens for research purposes

The number of specimen and the number of test batches are dependent on the established practice and the nature of the test program. Usually three or more specimens should be prepared for each test age and test conditions unless otherwise specified. Objective:

To produce and cure concrete test specimen in the laboratory under accurate control and test conditions using concrete that can be consolidated by rodding or vibration.

Reference Documents:

ASTM (C 192, C 192M-95, c3 1/31M-95, C 470-94, C617-94)

AASHTO (T 126-70, T 119-74) Apparatuses:

1. Cylindrical molds 2. Tamping rods, 5/8” (16mm) inch-diameter and 3/8” (10mm) inch-diameter 3. Trowel or Shovel 4. Slump cone device 5. Sampling and mixing pans

6. Balance 7. Air content device (optional) 8. Vibrator (optional) 9. Mixer (optional)

Procedure:

MIXING CONCRETE 1. Mix concrete in a suitable mixer or hand in batches as to leave about 10% excess after molding the test specimens. Hand-mixing procedures are not applicable to air entrained concrete or concrete with no measurable slump. Hand mixing should be limited to batches 3 3 of ¼ ft  (0.007 m ) volume or less. 2. In the case of machine mixing, add the cored aggregate; some of the mixing water, and the solution of admixture (if required), to the mix before starting its rotation. Start the mixer, and then add the fine aggregate, cement, and water with the mixer running. If it is impractical for a particular test to add the fine aggregate, cement and water while the mixer is running, these components may be added to the stopped mixer permitting it to turn a few revolutions following charging with coarse aggregate and some of the water. Mix the concrete, after all the ingredients are in the mixer for 3 minutes followed by 3minute rest, followed by 2 minutes final mixing. To eliminate segregation, deposit machinemixed concrete in the clean, damp mixing pan and remix by shovel or trowel until it appears to be uniform. 3. In the case of hand mixing, mix the batch in water tight, clean, damp, metal pan or bowl with a brick layer’s blunted trowel. 4. Mix the cement, powdered insoluble admixture (if required), and fine aggregate without the addition of water until they are thoroughly blended. 5. Add the coarse aggregate and mix the entire batch without the addition of water until the coarse aggregate in uniformly distributed throughout the batch. 6. Add water and admixture solution and mix the mass until the concrete is homogeneous in appearance and has a desired consistency. 7. Select portions of the batch of mixed concrete to be used in the tests for molding specimens so as to be representative of the actual proportions and conditions of the concrete. When the concrete is not being remixed or sampled cover it to prevent evaporation. 8. Measure the slump of each batch immediately after mixing.

9. Mold specimens as near as practicable to the place where they are to be stored during the first 24 hours. If it is not practicable to mold the specimens where they will be stored, move them to the place of storage immediately after being struck off. Place molds on a rigid surface free from vibration and other disturbances. Avoid harsh, striking, tilting, or scarring of the surface of the specimen when moving to the storage place.

Experiment No. 12:

Compressive Strength of Cylindrical Concrete Specimen

Discussion

Concrete mixture can be design to provide a wide range of mechanical and durability properties to meet the design requirements of the structure. The compressive strength of the concrete is the most resisting the load and reported in units of pound force per square inch (psi) in English system or megapascals (mPa) in SI units. Concrete compressive strength can vary from 2500 psi (17 MPa) for residential concrete to 4000 psi (28 MPa) and higher in commercial structures. Higher strength up to and exceeding 10,000 psi (70 MPa) are specified for certain applications. Compressive strength test results are primarily used to determine that the concrete mixtures are delivered meets the requirements of the specified strength, f’c in the job specifications.

Design engineers use the specified f’c to design structural elements. Their specified strength is incorporated in the job contact documents. The concrete mixture is design to produce an average strength of f’c higher than the specified strength such t hat the risk of not complying with the strength specifications is minimized. To comply with the strength requirements of a job specification both the following criteria shall apply: a) The average of three consecutive tests should equal or exceed the specified strength f’c. b) No single strength tests should fall below f’c by more than 500 psi (3.45 MPa), or by more than 0.10f’c when f’c is more than 5,000 psi (345 MPa).

It is important to understand that an individual testing below f’c does not necessaril y constitute failure to meet specifications requirements.When the average of strength test on a job are to be required , f’c the probability that individual strength tests will be less than the specified strength which is about 10 percent and ,this is accounted for the acceptance of criteria. When the strength tests results indicate that concrete delivered fails to meet the requirements of the specifications ,it is important to recognize that the failure may be in the testing,not the concrete. Objective:

To determine the compressive strength of cylindrical concrete specimens such as molded concrete cylinder.

Referenced Documents:

ASTM (C 39-94,C 39/C 39-01,C31,C617, C873)

Apparatus:

1. Universal testing machine 2. Measuring device 3. Balance, sensitive, to 0.1 gm. 4. Capping device Procedure:

1. Compression tests on specimens shall be made as soon as practicable after removal from th the moist storage. A 28-day test shall be performed within +-20 hours of the 28 day. Test specimens shall be kept moist by any convenient method during the period between removals from moist storage and testing. The y shall be tested in moist condition. 2. All test specimens for a given test age shall be broken within the permissible time tolerance prescribed below. 3. TEST AGE 24 HOURS 3 DAYS 7 DAYS 28 DAYS 90 DAYS

PERMISSIBLE TOLERANCE +-0.5 HOURS OR 2.1% 2 HOURS OR 2.8% 6 HOURS OR 3.6% 20 HOURS OR 3.0% 2 DAYS OR 2.2 %

4. With a clean rag or rush clean the bearing faces of the bearing blocks, test the specimens and exclusion controller (elastomeric cps). 5. Rest the specimen on the lower extrusion controller, place the top extrusion controller on the specimen on the specimen, and check the spacing between the sides of the specimen and the extrusion controllers to ensure no contact between the cylinder and the steel. Slide the specimen and extrusion controller configuration into the center of the concentric circles of the lower bearing block. Check the alignment with the upper bearing face after lowering it into position. 6. Apply the load to the specimen. During the first half of the anticipated loading phase, a higher loading rate shall be permitted. The remainder of the loading shall be 20 to 50 psi/second(0.14 to 0.34 Mpa) Note: For 6 inches (150 mm) diameter specimens, the loading rate shall be 550 to 1400 lbs. /second. For 4-inch (100 mm) diameter specimen, the loading rate shall be 250 to 620 lbs. /second.

7. Apply the load until the specimen fails, and record the maximum load supported by the specimen during the test rounded to the nearest 500lb. CALCULATION:

Cs= q/πR

2

Where: Cs=compressive strength (psi) Q=load at failure (lb-force) R=radius of specimen (in) For 6 –inch (150 mm) diameter specimen =Q/28.274 For 4-inch (100 mm) diameter specimen = Q/12.566 Experiment No.13:

Splitting Tensile Strength of Cylindrical Concrete Specimen

Discussion

Concrete has very low tensile strength due to the inhomogeneous nature of the material. When loaded in tension it typically fails along the interface between the aggregate and cement. Measuring the tensile the tensile strength of concrete directly is very difficult (i.e., grasping the ends of a long specimen and pulling); therefore, indirect method is used. The procedure involves loading a right cylinder on its side, until splits down the center. Splitting tensile strength is used to evaluate the shear resistance provided in concrete in reinforced aggregate concrete members. To measure the splitting tensile strength of concrete by the application of a

Objective:

diametric compressive force on a cylindrical concrete specimen placed with its axis horizontal between the platens of testing machine. Referenced Documents:

ASTM (C 496-96, C 498-71, C 496) AASHTO (T198-74, T 23, T 126) ACI 318-63

Apparatus:

1. Testing Machine capable of 100,000 lb 2. Concrete test cylinder 3. Bearing strips 4. Supplementary bearing bar or plate Test Specimen:

1. Moist-cured specimens, during the period between their removal from the curing environmental and testing, shall be kept moist by a wet burlap or blanket covering, and shall be tested in a moist condition as practicable. 2. Specimen tested at 28 days shall be in air-dry condition after 7 days moist curing Ο

Ο

Ο

Ο

followed by 21 days at 23 C ± 1.7 C (73 F ± 3 F) and 50 ± 5% relative humidity. Procedure:

1. Measure the dimension of the cylinder. Determine the diameter of the specimen to the nearest

0.01 in (0.25 mm) by averaging three diameters measured near the

ends and the middle of the specimen and lying in the plane containing the lines marked on the two ends. 2. Determine the length of the specimen to the nearest 0.1 inch (2.5 mm) by averaging at least two length measurements taken in the plane containing the lines marked on the two ends. 3. Center one of the plywood strips along the center of the lower bearing block of the testing machine. Place the cylinder on the plywood strip and align so that the lines marked on the ends of the specimen are vertical and centered over the plywood strip. 4. Place the second plywood strip lengthwise on the cylinder and place a 2 ˮ x 2ˮ x 14 steel bar over the plywood strip. 5. Lower the upper loading head until the assembly is secured in the machine. 6. Apply the compressive load slowly and continuously until failure. The rate at which the specimen should be loaded is 100 to 200 psi (690 to 1380kPa) per minute. 7. Record the maximum load applied, the type of failure and appearance of the concrete specimen. Calculation:

T = (T = 2P max IxI d) = 2P max / πLd) Where: T= splitting tensile strength, psi (kPa) Pmax = maximum applied load, lb-force (KN) L = length, in. (mm)

D = diameter, in. (mm)

Experiment No. 14:

Flexural Strength of Concrete

Discussion

Flexural strength is a measure of the tensile strength concrete. It is a measure of unreinforced concrete beam or slab to resist failure in bending. It is measured by 6 x 6 inches ( 150 x 150 mm ) concrete beam with a span length at least three times the depth. The flexural strength is expressed as Modulus of Rupture (MR) in psi (MPa) and is determined by standard test method ASTM C 78 (Third-point loading) and ASTM C 293 (center point loading) Flexural (MR) is about 10 to 20 percent of the compressive strength depending on the type, size and volume of coarse aggregate used. However, the best correlation for specific materials is obtained by laboratory test for given materials and mix. The MR is determined by third-point loading is lower that MR determined by center-point loading by as much as 15%. Designer of pavement use a theory based on flexural strength. Therefore, laboratory mix design based on flexural strength test may be required or a cementitous material content may be selected from past experience to obtain the needed design MR. some also use MR for field control and acceptance pavements. Very few use flexural testing for structural concrete. Agencies are not using flexural strength. Many state highway agencies have use flexural strength but are not changing to compressive strength for job control of concrete paving. Cylinder strength are also used for concrete structures. The concrete industry and inspection agencies are much familiar with traditional cylinder and compression test for control and acceptance for concrete. Flexural can be used for design purposes, but the corresponding compressive strength should be used to order and accept of the concrete. Any time trial batches are made, both flexural and compressive tests should be made so that correlation can be developed for field control.

Objective:

To determine the flexural strength of concrete specimens by the use of simple beam with center point loading.

Referenced Documents:

ASTM ( 293-94, , C 78 – 94, C 31, C 192, C 293 _ 02 ) AASHTO (T 198-74, T 23 ) ACI (325, 330 )

Apparatus:

1. Universal Testing machine 2. Loading apparatus

Procedure:

1. Measure the dimensions of the specimen and the record them in the date sheet 2. Turn the specimen on its side with respect to its position as molded and center in on life support blocks. 3. Center the loading system in relation to the applied force. 4. Bring the load applying-block in contact with the surface of the specimen at the center and apply a load between 3 and 6% of the estimated load. 5. Grind cap, or use leather shims on the specimen contact surface to eliminate any gap in excess of 0.004 inch (0.10 mm). Gaps in excess of 0.15 inch (0.38 mm) shall be eliminated by capping or grinding. 6. Apply the load on the specimen continuously and without shock. The load shall be applied at the constant rate to the breaking. Apply the load at such a rate that constantly increases the extreme fiber stresses between 125 and 175 psi/min. (0.86 and 121 MPa/min) when calculated in accordance with 7.1 until rupture occurs. 7. Take three measurements across each dimensions (one at each edge and at the center) to the nearest0.05 in. ( 1 mm ) to determined the average width and depth of the specimen at the point of fracture. If the fracture occurs at a capped section, include the cap thickness in measurement. Calculation:

MR = 3PL / 2bd2 Where: MR- modulus of rupture, psi (MPa)

P= maximum load applied as indicated by testing machine, in lb(N) L= span length .in inches (mm) b= average width of specimen in inches (mm) d= average depth of specimen, at the fracture, in inches (mm) Note: The weight of the beam is not included in the above calculation.

Experiment No. 15:

Nondestructive Test of Concrete

Discussion

Often it is desirable to know the characteristic on properties of a product without subjecting it to destructive tests. With the exception of some hardness test and proof loadings, the method discussed in the previous experiments will not permit the attainment of this objective, since most of the procedures, instead of using finished product, use specially prepared specimens and test them to either partial or complete destruction. Nondestructive tests may be divided into two general groups. The first group consists of tests used to locate defects just like visual inspection of the surface as well as the interior by use of drilled holes. Also test involving the application of the penetrants to locate surface cracks or examination of welded joints by the use of a stethoscope to detect changes in sounds caused by hidden defects. The second group of nondestructive tests consists of those used for determining dimensional, physical, or mechanical characteristics of a material or part. In this group are tests for the thickness of materials from only one surface or the determination of moisture content of wood by electrical means. It also includes certain hardness tests, surface-roughness test or methods employing force mechanical; vibration to determine the changes in natural frequency of the system due to changes in the properties of material. The evaluation of the condition of structure without destroying their usefulness must be accomplished by tests that are nondestructive. This applies to materials other than Portland cement concrete (PCC); but PCC is the material that will be used to illustrate some of the types of nondestructive tests available. This laboratory exercise investigates certain PCC properties using nondestructive test. Objective:

To determine the approximate compressive strength of concrete in-place.

Referenced Documents:

ASTM ( C 803, C 803 , C 805 – 02)

Apparatus:

1. Test Hammer with carborundum Field Checks:

1. Prior to use, make a check of the hammer calibration by hammering concrte of known strength. When possible, a more accurate check should be made by hammering test cylinders, immediately prior to checking.

2.

When using the hammer to test concrete for a pour on which the cylinder breaks indicated low strength (for compressive purposes) should also be made on other pour where cylinder breaks indicated satisfactory strength. This comparison should only be done with other pours made during approximately the same time period using the same mix and preferably on the same structure or project.

Procedure:

1. If the concrete surface is rough, grind points o be tested with the carborundum. 2. Operate the hammer in a horizontal position, when feasible. 3. Press the hammer plunger at exactly right angles to the surface of the concrete being tested. Press the plunger slowly and uniformly until released. Do not jerk or try to anticipate the plunger release. Do not press the lock button while apply pressure to the plunger. 4.

After impact, the rider will show the rebound value. Record the reading.

5.

Take a minimum of 15 rebound readings. Take only one reading at a given point. Very high readings may be caused by rock or steel near the surface at the point of impact, and very low readings may be caused by trapped air pocket near the surface at the point of impact.

6.

Covert the average reading to psi (kPa) from the chart. (Do not use the calibration curves on the hammer).

7.

Make correction to the psi (kPa) for the position of the hammer. Position Horizontal

Correction None

Vertical Up Vertical Down

Experiment No. 16:

Minus 500 (3400 kPa) Plus 500 (3400 kPa)

Determination of Compressive Strength of Concrete Hollow Blocks

Discussion

Hollow masonry units of Portland cement and sand, gravel, or other suitable aggregate are termed concrete blocks. Concrete blocks are used for interior and exterior bearing and nonbearing walls, partitions, and backing. The weight, color, and texture of concrete block depend largely on the type of aggregate used in its manufacture. Block made with sand and gravel or crushed rock weights 40 to 50 lb (18.1 kg to 20.4 kg) per 8” x 8” x 16” (203 x 203 x 406 mm) unit. These blocks are strong and durable, with a low absorption rate. Lightweight blocks are produced as non-load-bearing units, for use as backup walls, or as load-bearing units, for use as the finished surface of both interior and exterior walls. Standard concrete hollow blocks have the typical light-gray color of concrete. Colored blocks may be made with naturally colored aggregates or by including inert pigments in the concrete mix. Lightweight concrete block is used where a lightweight material with good strength and high insulating or acoustical qualities desired. Its use also simplifies the attachment of finish materials or accessories to structural wall, in that common nail can be driven into the block. Objective:

To determine the compressive strength of concrete hollow block.

Referenced Documents: Apparatus:

1. Compression Machine Procedure:

1. Place the bottom of the concrete hollow block on a compression block made of 1-inch thick plywood. Place another 1-inch thick plywood on top of the concrete hollow block. 2. Apply the compression load slowly until failure is attained and record the reading. Take note of the appearance of the concrete hollow block as well as the type of failure that will occur. 3. Test a total of three hollow blocks for each batch. Calculation:

Compressive Strength (CS) = P/A Where: 3

CS = compressive strength of the specimen, psi (KN/m ) P = maximum load, lb (KN) 2 A = cross-sectional area of the specimen, inches (m )

PART III. WOOD Wood is a natural renewable product from tress. Due to its availability, relatively low cost, ease of use and durability if properly maintained continues to be used as an important civil engineering material. Wood is used extensively for buildings, bridges, utility poles, floor, roofs, trusses and piles. Civil engineer used both natural wood and engineering wood products, such as laminates plywood, and strand board. In order to use wood efficiently it is important to understand its basic properties and laminations. That is why the civil engineer must run tests on wood.

Advantages of using Wood as an Engineering Material 1. The low energy content needed for production 2. The low cost of production 3. Wood is an environmentally friendly material 4. Wood is renewable material 5. Wood has a very high specific strength due to its low density and reasonable strength 6. Wood’s low density also makes it easier to transport 7. There are very low cost associated with the disposal of wood 8. Wood is electrically conductive 9. Most wood are non-toxic 10. Wood is low in thermal conductivity 11. Nails and screws do not measurably weaken wood, if put in care, showing that wood is very resistant to stress concentration.

Advantages of using Wood as an Engineering Material

1. There is large variability in properties between species and depending on growing conditions and the position of the wood within a trunk, within a species 2. Wood is dimensionally unstable, as water change its dimension 3. Wood’s strength decreases when wet 4. Time-dependent deformation such as creep and viscoelasticity occurs in wood 5. Wood is highly combustible 6. Wood is susceptible to termites, woodworm and infestations 7. Wood can’t be use at high temperature 8. Wood is susceptible to rot, and disease 9. Wood is highly anisotropic, although this can be limited by the use of plywood

EXPERIMENT No. 18:

COMPRESSION TEST OF WOOD PARALLEL TO THE GRAIN

DISCUSSION

Compression test is merely the opposite of the tension test with respect to the direction or sense of the applied forces. Compression parallel to the grain shortens the fiber in the wood lengthwise. An example would be chair or table legs, which are primarily subjected to downward, rather than lateral pressure. Wood is very strong in compression parallel to the grain and this is seldom a limiting factor in design. Specimen for compression test of small, clear pieces of wood parallel to the grains must be 50 x 50 mm (2 x 2 x 6 in.) or 50 x 50 x 200 mm. OBJECTIVE:

To determine the compressive strength of wood parallel to the grain.

REFERENCE DOCUMENTS:

ASTMD 143-83

APPARATUS:

1. Compressive Machine 2. Compressometer 3. Load indicator 4. Bearing block PROCEDURE:

1. Measure the cross section and length of the specimen to the nearest 0.01 inches. Record the dimensions and indicate the species of wood. 2. Place the specimen in the machine. Adjust dials or compressometer. Have an instructor check before starting the test.

3. Apply loads continuously throughout at the rate of 0.003in/in. of specimen length per minute 4. Record the maximum load to a point beyond the proportional limit. After failure, draw sketches and identify the type of failure. In case two or more kinds of failure develop, all shall be describe in the order of their occurrence. 5. Compute compressive strength in psi. CALCULATION:

        Experiment No. 19:

Static Bending of Wood

Discussion Most structures and machines have members whose primary function is to resist loads that cause banding. Examples mare beams, hooks, plates slabs, and columns under eccentric loadings. The design of such structural members may be based on tensile compressive and shearing properties accounted by various bending formulas. In many instances, however, bending formulas give results that only approximate the real conditions. The bending test may serve then as a direct means of evaluating behavior under bending loads, particularly for determining limits of structural stability of beams of various shapes and sizes. Flexural tests on beams are usually made to determine the strength and stiffness in bending; occasionally they are made to obtain a fairly complete picture of stress distribution in a flexural member. Beam test also offer a means of determining the resilience and toughness of m aterial in bending. If a beam specimen is to be tested for flexural failure, as in the case when modulus of rupture of a material is to be determined. It must be proportional that it does not fail by lateral buckling or in shear before the ultimate flexural strength is reached. In order to avoid shear failure, the span must not be too short with respect to the depth. For wood, small clear pieces of wood, 50 X 50 X 750 mm (2 X 2 X 30 in.) in size are tested under center loading, but large timber beam having a length of 5 m. are often tested under third-point loading.

Objective:

To determine the mechanical properties of wood subjected to bending and to study the failure of the material.

Referenced Documents :

ASTM (D 143 – 83, D 198 – 84)

Apparatus: 1. Universal Testing Machine

2. Beam support 3. Deflection gage

Procedure: 1. Mark the center and end points of the specimen for a 30-in span. 2. Place the beam in the machine with the ends placed on the supports and place the loading block at the center of the beam. The whole assembly shall be properly centered such that the loading block

is at the center of the machine’s loading head. 3. Lower the loading head until a small compressive load is applied to the beam. Place the deflection gage at the midspan in such a way that it can measure the midspan deflection of the beam. 4. Apply the load continuously at the rate of approximately 1000 pounds per minute. Take simultaneous load and deflection readings for increment of every 200 pounds until the maximum load has been reached. Remove the dial gage prior to the failure of the beam. 5. Sketch the appearance of the failure. 6. Plot a load-deflection curve and compute all the properties called for using the formula shown below.

Calculation:

3PmaxL MR =

2

2bh 3

PL E=

3

(S) 4bh Where:

Pmax and L = maximum load and span of the beam B and h = width and height of the cross-section S = slope of the load-deflection curve

Experiment No. 20:

Tensile Test Parallel to the Grain of Wood

Discussion:

Tensile stress elongates or expands an object. Measurement of tensile stress perpendicular to the grain is useful for quantifying resistance or spilling. Wood is relatively weak in tension perpendicular to the grain but it is very strong in tensile parallel to the grain. Due to the difficulties in testing and the limited use for such data, tension parallel to the grain has not been extensive measured and/ or reported to data. Tensile stress is measured in psi. The ultimate tensile stress parallel to the grain (UTS) is difficult to obtain experimentally with clear defect-free wood. The value parallel to the grain is of the order of 46-120 MPa at 12% moisture content whereas the tensile stress perpendicular to the grain may only be 2-6% of the parallel-to-grain value. Thus, it is difficult to get wood to fail in tension parallel to reason; only a limited value of data is available on the tensile strength of clear wood parallel to the grain. Values of tensile strength perpendicular are determined as an average of the values in the radial and tangential directions. Objectives:

To determine the tensile strength of wood parallel to the grain.

Referenced Documents: Apparatus:

1. Testing machines 2. Special grips 3. Calipers 4. Dial gage Procedure:

ASTM (D-143-83, D 198-84)

1. Measure and record the actual dimension of the specimen and indicate species of wood. 2. Assemble the necessary equipment and set up the test for loading. 3. Place the wood sample in the special grips. 4. Apply load continuously throughout test at rate of 0.05 inch/minute. 5. Record the tensile load and elongation as the load is applied. 6. Draw sketches and identify type of failure. 7. Compute the tensile strength of wood parallel to the grain. Calculation:

     Experiment No. 21:

Shear Test to the Grain of Wood

Discussion

Shear stress involves the application of stress from two opposite direction causing portions of an object to move parallel but opposite directions. Wood is very resistant to shearing perpendicular to the grain and this property is not measured via a standard test. Wood shears is much easier in a direction parallel to the grain _ consider a screw running perpendicular to the grain: it will shear out to the nearest end grain if a sufficiently large force is applied to the grain. Shear stress is measured in psi. A shear strength parallel to the grain ranges from 3 to 15 Mpa at 12% moisture content. Because wood is highly orthotropic .it is very difficult to get fail in shear perpendicular to the grain usually result in failure in another failure mode, such as compression perpendicular to the grain. A very limited amount of data suggests that shear strength perpendicular to the grain may be 2.5 -3 times that of the shear parallel to the grain. Objective:

To test the shearing stress parallel to the grain of wood.

Referenced Documents:

ASTM 143-18

Apparatus:

1. Testing machine 2. Caliper 3. Shear tool apparatus Procedure:

1. Measure and record actual dimensions of the shearing surface. 2. Place specimen in shear test assembly.

3. Place the assembly in the testing machine. Provide 1/8 inch offset along which failure occurs. 4. Set dials to monitor rate of load of application. 5. Applied continuously throughout at the rate of 0.0004 in./sec until failure. 6. Sketch the failure pattern and compute the shearing stress.

Calculation:

       

PART IV. METALS The element called metals together surely constitutes most important engineering materials. They can be combined with another and some nonmetals to form alloy that have characteristics superior to any pure metal for most purposes. Alloys with a great much combination of properties can be made. The reference to pure metals has to be taken, almost literally, with a grain of salt. Even when absolute purity is desirable, which is the case quire rarely, it cannot be fully attained. Whenever we

speak of “pure” metals, therefore, we mean metals with less than one (1) percent impurities. Metals are thought of as being divided into two groups, ferrous and nonferrous metals depending

on whether the major constituents are iron or not. The word “ferrous” is derived from the Latin noun ferrum, meaning iron. Ferrous metals are principally iron-carbon alloys containing small amounts of sulfur, phosphorous, silicon and manganese. Some are alloyed with copper, nickel, chromium, molybdenum or other elements to alert their physical and mechanical properties. Nonferrous metals and their alloys are also important group of engineering materials. Some have high strength-mass ratio, whereas, others have good antifriction quantities and resistance to corrosion, and still others are suitable for die-casting and extrusion. Heat-treatment does not generally improve their properties to the same extent as it does those of steel alloys. Cold-working, however, quite effective increases the yield strength of most nonferrous metals.

Experiment No. 22:

Tensile Strength of Steel Bar

Discussion

Most commercial specification for metal has requirements for physical properties as determined by the tensile-strength test. The properties include ultimate strength, yield strength or yield point, elongation, character of fracture, and reduction of area. In order to obtain complete information concerning tensile properties of metal, a stresses-strain curve should be determined experimentally. Strain corresponding to definite stresses imposed upon the specimen is measured by means of extensometer. For metal having no well-defined yield point, the yield strength is ordinarily determined, as explained previously. Ductile carbon steel has well-defined yield point. The tension test of steel is quite illustrative for some mechanical properties. If force deformation diagram are drawn, it is very easy to have an idea about the ductility or brittleness of the material. A ductile material is one in which large deformation is produced before the specimen fractures. Whereas a brittle material is one in which comparatively small deformation occurs before fracture. Besides, if the gage length and the original cross-sectional area are known, strain and stresses can be calculated from the force-deformation diagrams. The yield stress, at which large plastic deformation begin with small increase in stress, is an important characteristic of the concrete reinforcing steel. Another important in stress, is the ultimate stress, i,e., the maximum stress that can be carried by the material without any failure. While plain bars have circular cross-sections, so a nominal diameter is defined. Nominal diameter of a deformed bar is the diameter of the plain bar which has the same weight per unit length as the deformed bar. In tension test, percent elongation and percent reduction of area may be considered as the quantitative measures of ductility. Temperature, rate and type of loading affect the result of tension test.

Laboratory test show that the increase in yield strength is accompanied by an increase in tensile strength and hardness, too. However, the increase in tensile strength is not much. On the other, strain hardening reduces ductility. Objective:

To obtained the force-deformation diagram (stress-strain diagrams) of a plain bar and a deformed bar of concrete reinforcing steel and compare some of their mechanical properties in tension

Referenced Documents:

ASTM (A6/A6M, A36M, E8 -69) AASHTO (T 68-74)

Apparatus:

1. Universal testing machine 2. Extensometer 3. Vernier caliper Procedure:

1. Measured the total length L and weight W of the deformed bar specimen. Mark the gage length. 2. Attach the specimen to the universal testing machine (100 ton-capacity ). 3. Apply a tensile load satisfying all the requirements of the related standard. 4. Obtain the force- deformation diagram (stress-strain diagram) as graphs from the mechanical recorder of the machine. Reload the ultimate load Pu . Continue until load fracture of the specimen. 5. Measure the gage length after fracture (Lf) by connecting the two pieces. 6. Measure the final diameter dfd by vernier. Make about three mutual measurements. 7. Make calculation: 0.5

a) Determine the nominal diameter dn (mm) of the deformed bar using dn =12.8G G=weight /unit length (kh/m) which can be calculated using L and W b) Calculate the yield strength of the bar as

  .

c) Calculate the ultimate strength of the bar as

 using the ultimate load P  and u

Ao = original cross-sectional area Pu = read from graph d) Calculate the modulus of Elasticity E for the bar using:

   ( )    e) Calculate the percent reduction in are using:

    f) Calculate percent elongation using:

   PART V. ASPHALT Asphalt is a sticky brownish or black and highly vinous liquid or semi-solid that is present in most crude petroleum and in some natural deposits. Asphalt is composed almost entirely of bitumen. There is some disagreement amongst chemists regarding the structure of asphalt, but it is moats commonly modeled as a colloid, with asphalteness as the dispersed phase and maltenes as the continuous phase. It is literally scraped from the bottom of the barrel after all other petroleum-based products have been refined or processed. Asphalt is at least 80% carbon that explains its deep color. Sulphur is another ingredient found in the tar-like asphalt, as well as trace minerals. Asphalt is sometimes confused with tar, which is an artificial material produced by the destructive distillation of organic matter. Tar is predominantly composed of bitumen, but the bitumen content of tar is typically lower than that asphalt. Tar and asphalt have very different engineering properties. The tar from the crude oil is usually mixed with sand and gravel to form the finished product we call asphalt. The black tar forms a strong adhesive bond with the aggregate, which makes it durable. When used in road construction, asphalt is usually poured over a bed of heavier aggregate in a heated state, and then pressed into place by an extremely heavy steam roller. Once the fresh asphalt cools to ambient temperature, it becomes sturdy enough flexibility to accommodate natural variations in the roadbed. Because asphalt bears the weight of cars extremely well, it has become a very popular material for parking lot construction. Asphalt can be applied quickly on a prepared surface, which means a parking lot can be graded, poured and painted with little delay. Patching asphalt is usually a matter of bringing a new material to the affected area and pressing it into the cracks or potholes. This makes asphalt preferable to be more permanent material such as concrete. Repair crews can fix asphalt problem without blocking or removing entire section of roadway.

Asphalt is also popular sealant for roofs. Heated asphalt can be pumped to the roof of a new building and poured into place. While it is pliable, roofers can spread an even layer to form a nearlyimpenetrate barrier between the building and the elements. Over time, the aggregate may work its way out of the tar, but the overall integrity is comparable to other roofing methods. Asphalt is rather hard to transport in bulk (it hardens unless kept very hot) so it is sometimes mixed with diesel oil or kerosene before shipping. Upon delivery, this lighter material is separated out of the mixture. This mixture is often called bitumen feedstock or BFS. Other uses include airport runways, playgrounds, fence post treatments, and waterproofing for fabrics.

EXPERIMENT No. 23:

PENETRATION OF BITUMINOUS MATERIALS

DISCUSSION

The viscous or flow properties of bitumen are of importance, both at high temperatures encountered in processing and application and at low temperatures to which bitumen are subjected in service. Flow properties are complex and are further confused by changes in the colloidal nature of the bitumen that occur with heating. When the temperature is high enough for the bitumen to be liquid, the rate or shear is directly proportional to the shearing stress. As the temperature drops, however, these flow properties are complicated by elasticity and other effects. This has necessitated empirical test, which are used by the producer and consumer to measure the consistency of the bituminous materials at temperature comparable to those encountered in the service life of the bitumen. Among the most common of these test are the penetration and softening point test and various indices using them. Penetrate is the consistency of bituminous material expressed as the fiancé in tenths of a millimeter that a standard needle vertically penetrates a sample under known conditions of loading, time, and temperature. The most common conditions are 100 grams penetrating for 5 seconds at a temperature of 25°C (77°F). the penetration is measure of hardness, and typical values obtained are approximately 10 for hard coating grade asphalt, 15 to 40 for roofing asphalt, and up to 100 or more for keratin waterproofing materials. OBJECTIVE:

To determine the penetration of semi-solid and solid bituminous materials. The penetration test is used to determine the consistency of bituminous (asphaltic) material.

REFERENCE DOCUMENTS:

ASTM (D5-97, C 670, D 36) AASHTO T 49-74

APPARATUS:

1. Standard needle – 50.8 length by 1 mm 2. Penetrate Apparatus – with removable spindle (total weight of spindle is 50 gm) 3. Weight – 50 gm as required to bring total weight penetration less than 200 4. Sample Container – 55 mm by 35 mm depth for penetrate less than 200 5. 70mm diameter by 45mm depth for penetration between 200 and 350 6. Transfer dish 7. Water bath – 10 liter capacity with temperature control of 25° 8. Timing device – 0.1 sec resolution PROCEDURE:

1. Heat the sample, stirring to prevent local overheating, until it is sufficiently fluid to pour. Avoid incorporating bubble into the sample. 2. Pour the sample into the sample container to a depth, which is 10mm greater than the depth to which the needle to which the needle is expected to penetrate when cooled to the test temperature of 25° (77°F). 3. Allow the sample to cool for 1 to 1.5 hour for the small container and 1.5 to 2 hour for large container. 4. Place the container in the transfer dish and place it in the water bath at 25° (77°F). The small container shall remain in the bath for 1 to 1.5 hours and large container for 1.5 to 2 hour. 5. Place the 50 gm weight above the needle and spindle. The total weight is 100 gm. 6. Cover the container with water from the bath and place the transfer dish on the stand of the penetration apparatus (the penetrometer). 7. Position the needle by lowering it slowly until the needle’s tip just makes contact with the surface of the sample. 8. Zero the penetrometer dial. 9. Release the needle holder, allowing penetration of the asphalt to occur. After 3 seconds stop the penetration test.