問題一覧
1
Consolidation test is usually performed on ________ samples.
Both a and b
2
Under what climatic conditions do we use that lower penetration grade or hard asphalts.
Hot climate
3
For efficient compaction, the embankment materials should at the time of rolling be:
Optimum moisture content
4
In how many hours should concrete core samples be submerged in lime-saturated water before subjecting them to compression test.
At least 30
5
1.) If the bulk specific gravity of a bituminous mix is 2.343 and the dry stability is 3,000 Ibs., what is its index of Retained Strength (IRS) if its wet stability is 2,400 lbs?
80
6
What is the significance of the loss on ignition of cement?
It signifies pre-hydration or moistwre uptake of cement while it is shelved
7
Retarders are more usefull during:
Hot weather
8
As constructions work progress, you noticed that the materials delivered at the project site area different from the ones tested and that a passed the requirements. As materials engineer, what would you do?
Conduct immediate ratesting of the materials for verification purposes
9
Given : asphalt content of bituminous mix 5.50% Weight of specimen in air = 1200grams Weight of specimen in water =700grams Weight of specimen in SSD = 120Sqrams Calculate the bulk specific eravity of the asphalt specimen
1.576
10
What is the purpose of test piles?
To determine the required pile length
11
Slump is the subsidence of fresh concrete upon removal of a 30-cm truncated cone form. The slump test is performed as field control to
Concrete workability
12
What test determines the resistance to deformation of a compacted asphalt concrete mix?
Ductility test
13
What is the water-cement ratio that will produce the highest strenght of concrete?
0.45
14
The treatment of fresh concrete with the purpose of retaining sufficient water within the mass to permit hydration of cement is called?
Curing
15
Which of the following is not type of volume change of concrete?
Alr content
16
Which of the following are generally true in the production of high-strength concrete?
All of the above
17
When using a nuclear density gauge, which of the following is not a requirements?
Operator must wear thick clothes
18
When the strength test results of concrete beam samples are not acceptable, how many representative core/s shall be taken from each member or area of concrete in-place considered deficient in the newly completed concrete pavement?
At least 3 cores
19
What is the function of emulsifiers in liquid asphalt?
To prevent asphalt from hardening
20
Concrete with zero slump means that its water-cement ration is:
Low
21
The workability of a bituminous mix is dependent on the:
Temperature of mix
22
The temperature of concrete during the period of mixing while in transport and/or during placing shall not be permitted to rise above.
36C
23
What differentiates the composition of the item 201 from 200?
Iterm 201 contains less binder and smaller size of gravel than Item 200
24
The purpose of compacting a concrete mix is to?
All of the above
25
Concrete in the area represented by the cores will be considered adequate of their average strength is equal to?
At least 85% of and no single core ls less than 75% of f'c
26
Who would take samples of materials and bring them to the laboratory for testing
DPWH materials engineer
27
ASTM C-150 requires that the 28-day strength of mortar made from Type I Portland Cements be at least 27.6MPA. Three specimens were tested: two passed but one failed by more than 20%, as materials engineer, what will be your conclusion?
Perform and re-test since the date is inclusive
28
A mixture of asphalt cement and water with catalytic agent is called:
Emulsified asphalt
29
What is the minimum sample size needed for testing of cement
20kgs
30
Before concrete paving, the base of a roadway should be kept in moist condition and saturated with water for at least:
2hrs
31
The standard test specimen obtained in concrete for building projects is:
Cylinder
32
The minimium testing requirements for bituminous mix is one quality test for every tonnes or fraction thereof.
130
33
2. A set of three (3) core samples has the following compressive strengths: 4000psi, 3500psi and 2600psi. If the required strength is 3500 psi, the area represented by the core sample is?
Not acceptable
34
The optimum moisture content of soil is determined during
laboratory compaction
35
Bleeding of asphalt in a newly paves road is an indication of:
Excessive asphalt cement
36
Undersized reinforcing steel bars that satisfy the tensile and elongation requirements may be accepted provided that its underweight does not exceed:
6%
37
Unsuitable materials for embankment are:
Organic materials such as peat and muck
38
The selection by a standard method of a representative portion of a material for the purpose of ascertaining its characteristics is called:
Sampling
39
The results of the immersion/ compression test conducted on an asphalt mix sample area as follows: Dry stability = 2000kpa Wet stability = 1000kpa What is the resulting index of retained strength? Does it meet the specification requirement of item 310, bituminous concrete surface course?
50%, No
40
What will possibly be the result of using different brands of cement in concrete paving?
Different color after it has hardened
41
Sampling of freshly mixed concrete shouls be taken on the batch discharge of the transit mixer.
Middle
42
A one-lane road, with a pavement width of 3.5m and shoulder width of 0.5m on each side of the pavement, was designed to have subbased and base corses with a combined thickness of 300mm, the thickness of the subbase is 125mm, the spreading and compaction of the subbase and base oourses shall be carried out in?
3 Iayers over the full width of 4.5m
43
Soil properties can be improved by
stabilization
44
In the process of compaction of item 200 which contains sandy materials, only 80% density was attained. What is your recommendation in order to comply with the 100% min degree of compaction?
Adjust the water content
45
In pavement construction, what is the required density of the bituminous mixtures based on laboratory density, of the soil is properly compacted or compacted at maximum density, it will
All of the above
46
Which of the following factors does not affect the strength of concrete cores drilled from structure?
None of the above
47
A transit mixer for road construction was found to have a 6" slump of fresh concrete intent of the required 3", What will you recommnend if you are the assigned materials engineer?
Reject the concrete mixture
48
What is used to measure pavement surface irregularity
Falling weight defectometer equipment
49
What documentation should be maintained and kept updated by the materials engineer during project implementation.
Materials logbook
50
Which of the following is considered suitable as embankment materials
None of the above