Review Module – Construction

CONCRETE MIXTURE formworks is not required for footing. Provide 100 mm thick compacted gravel bedding.
(Swell factor for backfill is 115%, Unit weight of steel is 7860 kg/m3).
SITUATION. The ratio 1:1.5:3 (by weight) is used in a concrete mix.
Cement: 50 kg/bag of cement with specific gravity of 3.15 13. Determine the nearest quantity of excavation in m3?
Sand: Specific gravity of 2.2 A. 32.256 C. 30.240
Gravel: Specific gravity of 2.7 B. 35.526 D. 37.240
Water: 20 liters per bag of cement 14. Determine the nearest volume of compacted gravel m3?
1. Determine the volume of cement used for a bag of cement. A. 3.016 C. 1.016
A. 0.019 m3 C. 0.017 m3 B. 4.016 D. 2.016
B. 0.016 m3 D. 0.012 m3 15. Determine the nearest volume of backfill in m3?
2. Determine the volume of sand used for a bag of cement. A. 24.730 C. 22.220
A. 0.044 m3 C. 0.034 m3 B. 21.504 D. 31.510
B. 0.064 m3 D. 0.054 m3 16. Determine the nearest quantity of concrete (for the footings) in m3?
3. Determine the volume of gravel used for a bag of cement. A. 5.048 C. 8.064
A. 0.056 m3 C. 0.066 m3 B. 6.048 D. 7.064
B. 0.076 m3 D. 0.036 m3
4. Determine the total volume of concrete per bag of cement. SITUATION. A slab is to be constructed with a clear dimension of 4.5m x 7.0m.
A. 0.106 m3 C. 0.126 m3 17. Which of the following most nearly gives the quantity of standard plywood needed
B. 0.141 m3 D. 0.159 m3 for the formworks?
5. Determine the approximate number of bags of cement for a 25 m3 concrete A. 12 C. 16
member. B. 8 D. 6
A. 199 C. 263 18. If 286.65 bd ft is needed for the wood frame of the slab formworks, what is the total
B. 259 D. 236 length, in feet, if a 2” x 3” wood is used?
A. 423.75 C. 523.3
SITUATION. A certain structural member is to be poured with 30 ft3 of concrete using B. 477.75 D. 573.3
the proportions 1:2:3 by volume. Water cement ratio is 0.7 by volume. 19. If the concrete slab is to be reinforced by 12 mm Φ bar, what thickness of concrete
spacer for the bottom bars must be prepared prior to concrete pouring?
Materials Specific Gravity Unit Weight A. 20 mm C. 25 mm
Cement 3.15 94 pcf B. 30 mm D. 15 mm
Sand 2.40 110 pcf
Gravel 2.70 100 pcf 20. Estimate the cost of fencing a lot 20m x 30m with a 3m gate span at one end of
(20m). Estimate the total cost excluding the gate.
6. Find the approximate number of bags of cement.
A. 5 C. 7
a) Given as follows per square meter of fence.
B. 9 D. 11
13 pcs – 6” CHB @ P1.60/piece
7. Find the approximate volume of sand required in ft3.
3 kg reinforcing bars @ P0.60
A. 10 C. 14 ¼ bag of cement at P58/bag
B. 22 D. 18 1/60 cu.m. of sand @ P180/cu.m.
8. Find the approximate volume of coarse aggregate in ft3. Cost of labor and installation @ P30/sq.m.
A. 27 C.15
B. 21 D. 33 b) other cost
9. Find the approximate volume of water in ft3. Cost of footing, material and labor @ P160/cu.m.
A. 4.1 C. 6.0 Cost of excavation @ P20/cu.m.
B. 4.9 D. 7.0
Consider: Depth of footing from NGL = 0.6m
SITUATION. [NOV 2018] Thickness of footing = 0.2m
The basic data for proportioning trial batches for normal weight concrete with an Width of Footing = 0.6m
average compressive strength of 35 MPa at 28 days are as follows: Height of fence from NGL = 3m
Slump = 75 mm to 100 mm
Water – cement ratio by weight = 0.48 a. P25,713.24 b. P25,137.24 c. P25,417.42 d. P25,174.42
Specific gravity of cement = 3.15
Specific gravity of coarse aggregate = 2.68 SITUATION. [NOV 2009]
Specific gravity of fine aggregate = 2.64 A 4 m length pipe having a diameter of 600 mm is to be installed in one hour at a cost
Water (net mixing) = 180 kg/m3 of P570/m. One foreman has a rate of P50/hr., 2 skilled laborers have a rate P40/hr.
Entrapped Air = 1% and 10 unskilled laborers have a rate of P35/hr. A backhoe was rented for P800/hr.
Concrete unit weight = 23.6 kN/m3 and a compactor was rented at a rate of P120/hr.
10. What is the total solid volume of water, cement, coarse aggregate and entrapped Volume of cement needed per meter length is 0.07 m3 at P130/m3
air, if the dry weight of coarse aggregate is 10.1 kN/m3? Volume of sand needed per meter length is 0.15 m3 at P300/m3
A. 0.38 C. 0.12 VAT is 10% of equipment, labor and material cost.
B. 0.24 D. 0.69 Insurance is 30% of equipment and material cost.
11. For 10 m3 of concrete, how much cement (kN) is needed?
A. 57.1 C. 36.8 21. Which of the following gives the total cost of labor and equipment per meter length
B. 18.4 D. 9.8 of pipe?
12. If the combined solid volume of cement, water, coarse aggregate and entrapped A. P920 C. P1500
air is 0.55 m3, what weight of dry sand is required? B. P350 D. P420
A. 13.0 C. 25.9 22. Which of the following gives the cost of material per meter length of pipe?
B. 16.4 D. 11.6 A. P624.10 C. P745
B. P1000 D. P879.10
ESTIMATES 23. Which of the following gives the total cost of the project per meter length of pipe?
A. P1267.10 C. 1327.74
SITUATION. A bill of quantities is to be prepared for 14 square isolated footings B. 1320.45 D. 1420.24
(Length x Width x Thickness) 1.20m x 1.20m x 0.30m with depth of 1.5m. The footing
supports column with dimension 0.40m x 0.40m. The foundation is strong enough that
 Review Module – Construction

CRITICAL PATH METHOD (CPM) assuming a wide variety of shapes, again unlike the normal, which is always
symmetrical about its most likely value.
Earliest Start Time Rule:
Estimate of Expected Activity Time:
The ES time for an activity leaving a particular node is the largest of the EF times for
𝒂 + 𝟒𝒎 + 𝒃
all activities entering the node 𝒕=
𝟔
Latest Finish Time Rule: Estimating the Standard Deviation of an Activity Time
The LF time for an activity entering a particular node is the smallest of the LS times for 𝒃−𝒂
𝑺𝑫 =
all activities leaving that node. 𝟔
Slack is the amount of time an activity can be delayed without affecting the completion
date for the overall project. SITUATION. For the following PERT network given below (time duration is in weeks):
Most
The critical path activities are those with zero slack Optimistic Pessimistic
Activity Likely
Time Time
Time
WAYS OF REDUCING PROJECT DURATION 1–2 1 1 7
1. A strategic analysis
1–3 1 4 7
Here the analyst asks: “Does this project have to be done the way it is currently
1–4 2 2 8
diagrammed?” In particular, “Do all of the activities on the critical path have to be done
in the specified order?” 2–5 1 1 1
2. A tactical approach 3–5 2 5 14
In this approach the analyst assumes that the current diagram is appropriate and works 4–6 2 5 8
at reducing the time of certain activities on the critical path by devoting more resources 5–6 3 6 15
to them 26. Determine the expected project length.
A. 7 weeks C. 13 weeks
B. 17 weeks D. 27 weeks
SITUATION. Repeating floor-by-floor structural construction activities of Diaphragm- 27. Determine the Standard deviation of Project Length.
Shear Wall Building are shown below. A. 3.8 weeks C. 6.78 weeks
Immediate Duration B. 3 weeks D. 4 weeks
Activity
Predecessor (Weeks) 28. Determine the probability that the project will be completed on schedule if the
A -- 7 scheduled completion time is 20 weeks.
B -- 9 A. 94.873% C. 100%
C A 12 B. 84.134% D. 74.431%
D A, B 8
E D 9 29. [NOV 2021] Of all paths through the network, the critical path has the ….
F C, E 6 A. maximum actual time C. minimum actual time
G E 5 B. minimum expected time D. maximum expected time
24. Which of the following gives the duration of the critical path?
A. 35 weeks C. 32 weeks 30. [NOV 2021] Which of the following satisfy the requirements for estimating
B. 40 weeks D. 43 weeks expected activity times in a PERT network?
25. What is the longest delay that the activity C can have without causing delay in the I. Make use of three estimates
overall structural floor construction? II. Puts the greatest weight on the most likely time estimate
A. 8 weeks C. 5 weeks III. Is motivated by the beta distribution
B. 7 weeks D. 6 weeks A. III only C. II only
B. I only D. All of the above
PROGRAM EVALUATION REVIEW TECHNIQUE (PERT)
31. [NOV 2021] Which of the following is the calculation of the probability that the
critical path will be completed by the time T?
VARIABILITY IN ACTIVITY TIMES
I. Assumes that the activity times are statistically independent
A. Optimistic time
II. Assumes that the total time of the critical path has approximately beta
(Denoted by a): the minimum time. Everything has to go perfectly to achieve this time.
distribution
B. Most probable time III. Requires knowledge of the standard deviation for all activities in the
(Denoted by m): the most likely time. The time required under normal circumstances. network.
A. III only C. II only
C. Pessimistic time B. All of the above D. I only
(Denoted by b): the maximum time. One version of Murphy’s Law is that if something
can go wrong, it will. The pessimistic time is the time required when Murphy’s Law is 32. The earliest start time (ES) for an activity leaving node C (in the AOA approach)
in effect A. is the Max of the earliest finish times for all activities entering node C
ESTIMATING THE EXPECTED ACTIVITY TIME: B. equals the earliest finish times for the same activity minus its expected activity
The procedure for estimating the expected value of the activity times was motivated by time
the assumption that the activity time was a random variable with a particular probability C. depends on all paths leading from the start through node C
distribution. D. all of the above

Sample Beta Distribution: (a = 4, m = 7, b = 16) 33. The latest finish time (LF) for an activity entering node H (in the AOA approach)
A. equals the Max of the latest start times for all activities leaving node H
B. depends on the latest finish time for the project
C. equals the latest start time minus the activity time for the same activity
D. none of the above

34. The slack for activity G

A. equals LF for G – LS for G
B. equals EF for G – ES for G
C. equals LS for G – ES for G
This distribution (the beta distribution) has a minimum and maximum value, unlike D. none of the above
the normal distribution, which has an infinite range of values. It also is capable of