MATERIALS ENGINEER

The standard penetration test (SPT) is an in-situ-test that measures what?

depth of soil layer

Which of the ff. bituminous material is best recommended for sealing weakened plane joints?

joint filler asphalt (commonly called hard asphalt or blown asphalt)

The main problem associated with wrong practice of conveying concrete is called what?

segregation

The specifications call for 1:2:4 concrete mix. In a one bagger mixer, which of the ff. amount of

water is most likely required for the mix?

20 liters

A one-lane road, with a pavement width of 3.5 meters and shoulder width of 0.5 meter on each

side of the pavement, was designed to have sub base and base courses with a combined thickness

of 300mm. If the thickness of the sub base is a 125mm, the spreading and compaction of the

subbase and base courses shall be carried out in:

3 layers over the full width of 4.5 m

As materials engineer, what is the area of the trial section that you would recommend to check the

suitability of the materials and efficiency of the equipment to be used for item 310 Bituminous

Concrete Surface Course?

about 500 sq.m

Per program of work, the estimated volume of Item 201 materials is 7500 cu.m. How many

grading and plasticity tests are required based on the DPWH minimum testing requirements?

25 grading and 25 plasticity

Bituminous concrete mixes contain asphalt by weight equivalent to what?

5 to 8 %

Quality of factory-produced reinforced concrete pipes may be best establishment through what?

Test of concrete pipes samples

Where do we take additional cores when the measured of any core taken from the pavement is

deficient in thickness by more than 25mm?

at no less than 5 meter intervals parallel to the centerline in each direction from the affected

location

The results of the Immersion-Compression test conducted on an asphalt mix sample are as follows:

Dry stability = 2,000 Kpa

Wet stability = 1,000 Kpa

Quality Control testing in a DPWH project is the responsibility of the_________?

Contractor Materials Engineers

As materials engineers, when is the right time to start sampling and testing aggregate of the

course materials?

Before the course materials be incorporated in the project.

The spot test on asphalt is used to determine what?

overheating during manufacture

Under what climatic condition(s) do we use the lower penetration grade or hard asphalt?

hot climate

Sampling of the freshly mixed concrete should be taken on the ______ batch discharge of the

transit mixer?

middle

Soft and unstable soils were encountered during the course of sub-grade preparation. If you were

the materials engineer assigned to the project, what is the most effective and cheaper method that

you would recommend to stabilize the soil prior to the construction of the subbase course?

geotextiles

How many times per layer should a concrete specimen molded in a 6”x6”x12” beam mold be

rodded?

63 times

What is the basis for acceptance or rejection of any construction materials?

Materials Test Reports

In testing concrete cylinder sample the load applied should be continuous without shock at a

constant rate within the range of _______ per second.

0.14 to 0.34 Mpa per second or 20 to 50 psi per second.

During the application of the first half of the anticipated load a loading shall be permitted.

higher rate

Initial rolling in bituminous mixes shall be performed with a ___________ roller.

Pneumatic-Tire roller

Final rolling in bituminous mixes shall be performed with a ____________ roller.

3-wheel or tandem type steel wheel roller

Rolling of Bituminous mix shall be discontinued whenever it begins to produce excessive

__________or __________.

pulverizing of the aggregate or displacement of the mixture

Final rolling shall be continued until roller marks are eliminated and a minimum _________ mass

percent of the density of the laboratory compacted a specimen prepared in accordance with

AASHTO T160 has been obtained.

95 mass percent

Sample from compacted bituminous mix shall be neatly cut by a saw or core drill. Each sample

shall be at least ___________.

150mm x 150mm x 100mm diameter full depth

For surface Tolerances the surface (bituminous mix) will be checked by the used of a __________

at sites selected by the engineer.

3-m straight edge

If the volume of coarse aggregate intended in your project in 85 cu.m., how many grading test will

you perform?

1 grading test

What is the most common method adapted by DPWH in the determination of density of the soil in

place?

sand cone method

What is the minimum sample for moisture content determination if the maximum size of particles is

50mm (2 inches)?

1000 grams

What is the minimum mass of field sample for a maximum size of fine aggregates at 4.75mm

(no.4)?

20 kgs.

What is minimum mass of field samples for coarse aggregate with a maximum nominal size of

aggregates of 50mm (2 inches)?

75 kgs.

What is the minimum mass/quality of samples for Portland cement to be tested for quality test in

the laboratory?

10 kgs.

What is the minimum mass/quality of samples for asphaltic materials?

5 liters

The minimum mass/quantity of samples for asphalt mix?

10 kgs.

The submission of any type of samples in the laboratory, what should you accomplished and to be

submitted together with the samples?

sample card

If the minimum yield strength of a grade 40 steel bars is 40,000 psi, what is the equivalent

MN/m2?

276 Mpa

If the minimum yield strength of a grade 60 steel bars is 414 Mpa, what is the equivalent in PSI?

60,000 psi

How many samples for quality of steel bars grade 40 if there are 15,500 kgs. of steel bars all

25mm 0 at site?

2 samples @ 1 meter long

What is the minimum mass of yield samples for coarse aggregates with a maximum nominal size of

aggregate of 75mm (3inches)?

100 kgs.

What is the minimum mass of coarse aggregates retained on the 200mm sieve shall be set a side

for sieve analysis for 50mm (2 inches) particle size?

2 kgs.

What is the minimum average strength requirement for non load bearing concrete hollow blocks?

4.14 Mpa.

What is the minimum average strength requirement for a load bearing concrete hollow blocks?

6.9 Mpa.

What is the average deficient thickness per lot of cores specimen where no payment is

recommended on the project?

more than 25 mm

What is the maximum average deficient thickness per lot of cores specimen where 100% payment

is recommended?

5 mm maximum

Concrete in the area represented by the cores will be consider adequate if the average strength of

the cores is equal to at least ________ of the specified strength, f’c and no single core is less than

75% of f’c.

85% f’c

The weighted loss of fine aggregates subjected to 5 cycles of the sodium sulfate soundness test

should not exceed.

10 mass %

The recommended type of Portland cement to be used in concreting unless otherwise provided for

in the special provision:

type 1

Portland cement maybe/shall be rejected if:

- it has partially set

- it contains lumps of cake cement

- it comes from a discarded or used bag

Fine aggregates shall be rejected when if fails in the ________ for organic impurities.

colormatic test

Fine aggregates used for PCCP shall not contain more than ________ of materials passing the

0.075 mm (no. 200 sieve) by washing.

3 mass percent

The coarse aggregate used for PCCP shall not contain more than ________ of materials passing

the 0.075 mm (no. 200 sieve) by washing.

1 mass percent

The mass percent of wear or abration loss of coarse aggregate used for when by AASHTO T-96

should not exceed.

50%

The weighted loss of coarse aggregate when subjected to five (5) cycle of the sodium sulfate

soundness test should not exceed.

12 mass percent

The used dowel bars used in PCCP is

plain round bar

A department Order series of 1997 give supplement guidelines on the conduct of Project

assessment by the Quality assurance units Regional Office (QAU-RO)

D.O. #52

A Department Order series of 1997, Revised DPWH Standard specification for Elastomeric bearing

pads for bridge superstructures.

D.O. #20

What is the maximum compressive strength of 150 mm x 300 mm concrete cylinder specimen at

28 days for class B concrete?

5000 Psi (37.7 Mpa)

What is the maximum compressive strength of 150 mm x 300 mm concrete cylinder specimen at

28 days for class C concrete?

3000 Psi (20.7 Mpa)

The weepholes shall be placed at the lowest points where free outlets for water can be obtained

and shall be spread not more than:

2 meters center to center

One of the most common method used in compaction test/moisture density relation test of soil is:

AASHTO T-180

Which of the ff. common method used in compaction test/moisture density relation test of soil

adopted by DPWH:

AASHTO T-99 and AASHTO T-180

f you are to use AASHTO T-99 method (standard proctor test) in compaction test, what is the

weight of rammer to be used?

2.5 kgs. (5.5 lbs.)

Using the standard proctor test or AASHTO T-99, what is the height of drop to a free fall above the

elevation of the soil and uniformly distributes such drops to the soil surface?

305 mm (12”)

Using the standard Proctor test or AASHTO T-99 or moisture density relation test, what is the

recommended no. of blows per layer?

25 blows

Using the modified Proctor test (AASHTO T-180) method for moisture density relation test of soil,

what is the recommended no. of blows per layer?

56 blows

Using again the modified Proctor test ( AASHTO T-180) method for moisture density relation test of

soil, what is the height of drop to a free fall above the elevation of the soil and uniformly distributes

such drops to the soil surface?

457 mm (18”)

What is the capacity or the computed volume of mold using 6” (152 mm) mold for both AASHTO T-

99 & AASHTO T-180 method?

0.002124 m 3

What are the data’s needed in moisture density relation test of soil 2 most common method?

– maximum dry density (MDD)

- optimum moisture content (OMC)

The prime coat shall be left undisturbed for a period of at least ________ hrs. and shall not be

opened to traffic until it has penetrated and cured sufficiently so that it will not be picked up by the

wheels for passing vehicles.

24 hrs.

Concrete vibrators shall operate at maximum spacing of ________.

60 cm

Stockpiles of concrete aggregates shall be built-up in layers of not more than in thickness.

one (1) meter

All washed aggregates shall be stockpiled or binned for draining at least ________ hrs. before

being batched.

12 hrs.

Concrete not in place within ________ from the time the ingredients where charged into the

mixing drum or that has developed initial set shall not be used.

90 minutes

Shall not be painted or coated with asphalt or other materials or enclosed in tubes or sleeves.

tie bars

Mortar that is not used within ________ after the water has been added shall be discarded.

90 minutes

The maximum tensile strength of the wire mesh for gabions shall be

586.1 Mpa

A wire mesh made of galvanized steel used as a protection works.

gabions

Minimum diameter of gabions per standard specification requirements

2.70 mm

Determines the hardness and stability of the compacted asphalt pavement

core test

Sampling of PCCP/asphalt core specimens shall be taken from the pavement using:

core drill

Size of asphalt core specimen for thickness and density determination:

– at least 150 mm x 150 mm

- 100 mm diameter full depth

The diameter of asphalt core specimens shall be at least equal to:

one and one half times the maximum size of aggregates

The thickness of asphalt core specimens shall be at least equal to:

two (2) times the maximum size of aggregates

Obtaining asphalt core specimens for each full days operation shall be:

at least one but not more than three (3) core samples

Determining the thickness of asphalt core specimens is by:

averaging the four sides of the core samples

Bituminous mixture will be measured by:

tons

The average of ________ measures are made on the asphalt core specimens in determining the

thickness.

4

In bituminous mixture, ________ will not be permitted as a method of measurement.

batch weights

A core shall be taken for every ________ if no core was taken at the end of each days operation.

100 Lm per lane

The average of four (4) measurements on the asphalt core specimen is to determine the

thickness

The computation for the quantity of bituminous mixture area the ff.

Given:

Paving length represented, m = 120

Thickness, cm = 5.0

Width, m = 3.05

Total length of pavement, m= 380

Density, gm/cm 3 = 2.221

40.64 tons

Main constituents of asphalt which is found in nature or as a residue in petroleum refining.

bitumen

Asphalt is a dark ________ cementations material, solid or semi-solid consistency

brown to black

Sampling bituminous mixes is one (1) sample every:

75 cu.m. or 130 m.t.

Sampling of asphalt is one (1) sample for every:

200 drums or 40 m.t.

Sampling of solid asphalt is one (1) sample for every:

10 lbs.

Representative quantity of one sample in sampling liquid asphalt is ________ sample for every:

1 quart to 1 gallon

During the breakdown rolling of asphalt mix, it is carried out by:

pneumatic roller

In rolling asphalt mix, what phase of rolling is to remove the marks by the

other roller?

final rolling