estimating bill of materials

INTRODUCTION: Estimation is the approximation of a result which is usable in business and economics. Estimation in project planning can be particularly significant, because plans for the distribution of labor and for purchases of raw materials must be made, despite the inability to know every possible problem that may come up. Furthermore, such plans must not underestimate the needs of the project, which can result in delays while unmet needs are fulfilled, nor must they greatly overestimate the needs of the project, or else the unneeded resources may go to waste. The purpose of this activity is that we will learn on how to estimate our building plan in such time it will not be hard for us to make estimation when we will be in the field. This will help me in my chosen field because this is one of the important things like getting the contract when we are already professionals.

PROCEDURE:  Building plan is prepared for estimates especially the sections of important points.  Necessary specifications are required for the steel bars and lateral ties used in the columns.  Study the building plan specifically the foundation plan and floor framing plans.  Get the height of the column and also for the depth of footing and ground spacing.  Determine the number of steel reinforcing bars for each group and its sizes.  Make an estimate of the main bars in each column and footing details and slab using different methods in obtaining the estimates.

DATA GATHERED:  Estimating Square Concrete Column by Linear Method: Computations for column 1 and 2 are the same since they have the same dimension. So, the total number of columns in the ground floor is 16. 

Total length of the column 1 and 2 in ground floor No. of columns x height

16 columns x 3 meters = 48 meters Refer to Table 1-4 in Estimate book by Max B. Fajardo Jr. page 23. Along 30 x 30 cm. column, using 40 kg cement class “A” concrete, multiply: Cement Sand Gravel 

: : :

48 x 0.810 = 38.88 bags say 39 bags 48 x 0.45 = 21.60 cu. m. 48 x 0.90 = 43.2 cu. m.

Total length of the column 1 and 2 in 2nd floor No. of columns x height 16 columns x 3.15 = 50.40 meters Refer to Table 1-4 in Estimate book by Max B. Fajardo Jr. page 23. Along 30 x 30 cm. column, using 40 kg cement class “A” concrete, multiply: Cement Sand Gravel

: : :

50.40 x 0.810 = 40.824 say 41 bags 50.40 x 0.45 = 22.68 cu. m. 50.40 x 0.90 = 45.36 cu. m.

The total number of columns 1 and 2 in 3rd floor is 11 

Total length of the column 1 and 2 in 3rd floor 14 columns x 2.70 meters = 37.80 meters Refer to Table 1-4 in Estimate book by Max B. Fajardo Jr. page 23. Along 30 x 30 cm. column, using 40 kg cement class “A” concrete, multiply: Cement Sand Gravel

: : :

37.80 x 0.810 = 30.618 say 31 bags 37.80 x 0.45 = 17.01 cu. m. 37.80 x 0.90 = 34.02 cu. m.

 Estimating Foot Slab by Volume Method: Since there is only one footing in the foundation plan; Volume of 16 footing slab

V = 16 (0.25 x 1.20 x 1.20) V = 5.76 cubic meters Refer to Table 1-2 in Estimate book by Max B. Fajardo Jr. page 8. Using 40 kg. cement class “A” concrete, multiply: Cement Sand Gravel

: : :

5.76 x 9.0 = 51.84 say 52 bags 5.76 x 0.5 = 2.88 cu. m. 5.76 x 1.0 = 5.76 cu. m.

 Estimating Main bars and Lateral ties in Columns: Main Bars for Column 1 

At Ground floor

= (height of column + footing depth + ground floor spacing) x No. of main bars x No. of column 1 = (3 + 1 + 0.20)(6)(4) = 100.80 m. 

At 2nd floor

= height of column x no. of main bars x no. of column1 = 3.15 x 6 x 4 = 75.60 m. 

At 3rd floor

= height of column x no. of main bars x no. of column1 = 2.70 x 6 x 2 = 32.40 m. The combined column for C1: 100.80 + 75.60 + 32.40 = 208.80 m. 208.80/6.00 meters = 34.80 say 40 pieces Main Bars for Column 2 

At Ground floor

= (height of column + footing depth + ground floor spacing) x No. of main bars x No. of column 2 = (3 + 1 + 0.20)(8)(12) = 403.20 m.



At 2nd floor

= height of column x no. of main bars x no. of column 2 = 3.15 x 8 x 12 = 302.40 m. 

At 3rd floor

= height of column x no. of main bars x no. of column 2 = 2.70 x 8 x 12 = 259.20 m. The combined column for C2: 403.20 + 302.40 + 259.20 = 964.80 m. 964.80/6.00 meters = 160.80 say 161 pieces Lateral ties Number of ties required in each typical column by using this formula: Length of Column Spacing of ties 

= Number of ties per column

At Ground floor

(C-1 with 10 mm dia.): 3.00 m. ht. = 20 ties 0.15 m No. of Lateral ties: 20 + 1 = 21 pieces Total ties: 21 pieces x 4 columns = 84 pieces (C-2 with 12 mm dia.): 3.00 m. ht. = 20 ties 0.15 m No. of Lateral ties: 20 + 1 = 21 pieces Total ties: 21 pieces x 12 columns = 252 pieces 

At Second floor

(C-1 with 10 mm dia.): 3.15 m. ht. = 21 ties 0.15 m No. of Lateral ties: 21 + 1 =22 pieces Total ties: 22 pieces x 4 columns = 88 pieces (C-2 with 12 mm dia.): 3.15 m. ht. = 21 ties 0.15 m

No. of Lateral ties: 21 + 1 = 22 pieces Total ties: 22 pieces x 12 columns = 264 pieces  

At Third floor (C-1 with 10 mm dia.): 2.70 m. ht. = 18 ties

0.15 m No. of Lateral ties: 18 + 1 = 19 pieces Total ties: 19 pieces x 2 columns = 38 pieces (C-2 with 12 mm dia.): 2.70 m. ht. = 18 ties 0.15 m No. of Lateral ties: 18 + 1 = 19 pieces Total ties: 19 pieces x 12 columns = 228 pieces The Length of one lateral tie by getting the perimeter multiplied by two is: L = 2 (a + b) = 2 (0.3 + 0.3) = 1.20 meters The commercial length of steel bars that we chose is 6.00 meters. Therefore, 6.00 meters/1.20 meters = 5.0 ; exactly 5 pieces could be derived from a 6.0 meters long steel bar. 

Total Number of ties in Column 1 and 2: Column 1 – 84 + 88 + 38 = 210 ties with 10 mm diameter Column 2 – 252 + 264 + 228 = 744 ties with 12 mm diameter

ORDER:

(C-1 with 10 mm) 210/5.0 = 42 pieces (C-2 with 12 mm) 744/5.0 = 148.8 say 149 pieces

DISCUSSION, ANALYSIS AND INTERPRETATION OF RESULTS: First, I studied all the relevant project drawings like elevations, framing plan, footing and column details. Different methods were used in obtaining the values needed for the computation. In getting the estimates for the concrete I used the volume method which is the area multiplied by its thickness. The result obtained is multiplied by the number of columns so that I can get the estimate for cement, sand and gravel. For the reinforcement, the number of columns to be erected is studied. The length of columns and sizes of vertical bars are

classified. The assumed length of commercial bars to be ordered is 6 meters. And for the concrete, the class “A” with 40 kg will be used.

CONCLUSION: Therefore, I learned that estimation is very significant in projects like making a building plan because it is a method of calculating various quantities to be incurred on a particular work or project. In estimating the steel bar reinforcement the first thing that must be considered is the length and quantity of a particular reinforcement.

REFLECTION: Its importance is that it decides whether the proposed plan matches the funds available or not. In case, the available funds doesn’t suit the estimated cost of work we can reduce it. It will also give an idea of the time required for the completion of work.

CAPITOL UNIVERSITY COLLEGE OF ENGINEERING Cagayan de Oro City BUILDING DESIGN Activity No. 2

ESTIMATING BILL OF MATERIALS TITLE EVALUATION RATING: DATE PERFORMED : July 4, 2012 DATE DUE

I. Hand-on Performance (25 pts.) Criteria

: Manifestations of skills in manipulating equipments, apparatuses, materials etc. (5pts.) Observance of class hours (5 pts.)

July 9, 2012 GROUP NO. :

SUBMITTED BY

Following procedures correctly (5 pts.) Working closely and sharing ideas with group-mates (5 pts.) Observing laboratory rules and maintaining order in laboratory premises (5 pts.) II. Laboratory Report (25 pts.)

:

Bethel Princess T. Flores

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STUDENT

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SUBMITTED TO

:



Engr. Genevieve A. Gabule INSTRUCTOR

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Correctness of data and computations (5 pts.) Analysis of Results (5 pts.) Appropriateness of conclusions (5 pts.) Presentation of figures and report write-ups (5 pts.) Promptness (5 pts.)

Total Score (50 pts.)

REMARKS : 1st SEMESTER SCHOOL YEAR 2012 - 2013

Actual Score