4. CCME REVIEW SAMPLE QUESTIONS (301-400)

For Contractor Consultant Materials Engineer

it evaluates the structural strength of coarse aggregate. It gives an indication of quality as determined by resistance to impact and wear. It also determines whether the aggregates will have degradation during traffic or rolling.

What is Significance of abrasion test is that?

No. 12 (1.70 mm)

What is the sieve used in sieving materials for abrasion test?

14 days

At what age should a concrete beam sample be tested for flexural test?

R = PL/bd2

How to compute the flexural strength of concrete beam sample tested at third point?

R = 3PL2/bd2

How to compute the flexural strength of concrete beam sample tested at center point?

16 mm Ø and 610 mm long with the tamping end rounded to a hemispherical tip of the same Ø as the rod.

What is the size of the tamping rod used is sampling concrete?

6 pcs per 10,000 units (12 pcs if more than 10,000 units)

Concrete masonry (hollow blocks) if subject to test, how many samples are required?

Individual = 5.5 MPa (800 psi) minimum

Average (for 3 samples) = 6.9 MPa (1000 psi) minimum

What is the strength requirement for load bearing concrete masonry units?

Individual = 3.45 MPa (500 psi) minimum

Average (for 3 samples) = 4.5 MPa (600 psi) minimum

What is the strength requirement for non – load bearing concrete masonry units?

to determine the yield and tensile strength of the bar as well as its elongation and is used to classify the bars into grade.

What is the significance of testing reinforcing steel bars?

To evaluate the ductile properties of RSB

What is the significance of bending test for RSB?

1 can (gal or pail)/ 100 cans (gal or pail)

What is the required testing requirement for paints?

slow - setting emulsified asphalt

SS – l or SS – lh is what kind of asphalt?

24 hours

For how many hours or how long shall a bituminous prime coat be left undisturbed?

cut – back asphalt

What kind of asphalt is used as tack coat?

25 pcs

One (1) set of concrete cylinder sample shall be taken for every how many pieces of RCCP?

thickness and density

What is being determined in a core sample from asphalt pavement?

materials logbook

All records regarding quality control such as accomplishment, daily activities, weather, etc. are recorded in a _____

depth of soil layer

The Standard Penetration Test (SPT) is an in – situ test that measures what?

segregation

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

three (3) layers over the full width of 4.5 m

A one – lane road with a pavement width of 3.5 m and shoulder width of 0.5 m on each side of the pavement was designed to have subbase and base courses with a combined thickness of 300 mm. If the thickness of the subbase is 125 mm, the spreading and compaction of the base and subbase courses shall be carried out in _____?

higher

During the application of the first half of the anticipated load a _____ rate of loading shall be permitted?

Test of concrete pipe samples

Quality of factory – produced RCCP may be best established through what?

geotextiles

Soft and unstable soils were encountered during the course of subgrade preparation. If you were the ME 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?

63 blows per layer

How many times per layer should a concrete specimen molded in a 6” x 6” x 21” beam mold be rodded?

pulverizing of the aggregate, displacement of the mixture

Rolling of bituminous mix shall be discontinued whenever it begins to produce excessive _______ or _______.

29ºC

In placing concrete, the required temperature should be less than ____

12 sets

How many concrete cylinder samples is required for a 300 pcs RCCP?

6 pcs RCCP

If concrete cylinder is not available for a 300 pcs RCCP, how many pipes shall be subjected to test?

not exceeding 45 minutes and that water – cement ratio is not exceeded.

If there is a necessity to add water to the concrete mix in order to increase its workability (provided concrete does not exceed specified slump), how many minutes after the initial time of mixing does adding water be permitted?

TAR – is a viscous liquid obtained from the distillation of coal or wood.

PETROLEUM ASPHALT – are the products of the distillation of crude oil.

What are the two (2) types of bitumen that are commonly used in the bituminous mixture?

Asphalt cement, cut – back asphalt, emulsified asphalt

What are the three (3) major petroleum asphalts?

GASOLINE – for rapid curing type

KEROSENE – for medium curing type

DIESEL – for slow curing type

What are the solvents of cut – back asphalts?

CATIONIC EMULSION – works better with wet aggregates and in cold weather. It is a positively charge electron.

ANIONIC EMULSION - adheres better to aggregates which have positive charge. It is a negatively charge electron.

Emulsified asphalts are either _____ or _____.

asphalt cement

What is the bituminous material used in Item 310?

grade and quantity of asphalt

What greatly affects the service of asphalt cement?

climatic condition

What influences primarily the grade of asphalt selected?

three (3) weeks

How many weeks do the producer of asphalt mix or the contractor shall submit the job – mix formula?

DPWH PE and ME

Who will approve the job – mix formula?

a. grading of aggregates

b. percentage and type of asphalt

c. temperature of aggregates and asphalt

d. temperature of mixture upon delivery or time of compaction

The job – mix formula contains provisions the following:

66ºC to 107ºC

When tar is used, what is the temperature that the mixture shall be placed?

when the mixture is still hot and workable

When is the right time to compact in order to attain the required density?

trial section

What is to be done in order to determine the number of passes that would attain the required density?

temperature

What needs to be controlled during the mixing and compaction and is of great significance in the strength of the resulting pavement?

It should begin from the sides and proceed longitudinally parallel towards the center line, each trip overlapping one half the roller’s width.

In Item 310, how is rolling be done?

degree of compaction

After the final rolling, what will be checked?

95% of the laboratory compacted density

The compacted pavement shall have a density equal to or greater than _____

when the pavement has cooled to atmospheric temperature

When will the traffic be permitted to utilize the pavement?

by the use of core drill or saw

How do we take sample from the finish pavement?

40 mm – 75 mm

What is the allowable slump of a workable concrete if not vibrated?

10 mm – 40 mm

What is the allowable slump of a workable concrete if vibrated?

not less than 50 seconds or more than 90 seconds

When concrete is mixed in a central mixing plant, what is the time of mixing?

It shall not exceed 45 minutes if hauled in non – agitating trucks and 90 minutes if hauled in truck mixers or agitators.

In transporting concrete, what is the time elapsed from the time water is added to the mix until the concrete is deposited in – place at the site?

by the use of vibrator inserted in the concrete vertically

How is concrete consolidated?

longitudinal construction joint

If the lanes are concreted separately, what kind of joint in a form of a keyway is used?

deformed steel tie bars

What kind of bar is placed perpendicular to the joint stated in the preceding problem?

not less than 50 mm

What is the depth of the weaken plane joint when sawed with a concrete saw?

not less than 6 mm

The width of the weaken plane joint is _____

sawing shall be omitted

What shall be done if cracks appear at or near the joint prior to the time of sawing?

asphalt or other materials

Tie bars shall not be coated or painted with _____

dowel

What is the material that is used as a load transfer device held in a position parallel to the surface and center line of the slab of pavement?

a thin film of bitumen

To protect dowels from corrosion and to facilitate sliding in concrete, it shall be coated with _____

brooming

The surface of the pavement shall be roughened by means of _____

1.5 mm

What is the depth of corrugation produced by brooming in the surface of the pavement?

72 hours

The surface of a newly put concrete when has sufficiently set shall be cured for a period of _____

a. by covering the concrete with mats saturated with water

b. by thoroughly wetting the pavement

c. by ponding

d. by applying curing compound immediately after finishing of the surface

The curing of the pavement is done by means of the following:

after the curing period or before it is opened to traffic

When is the right time to seal the joints?

the placement of stone or boulders and the ratio of cement and fine sand

What is the difference between Item 504 and Item 505 (bluebook ’95)?

Materials Engineer of the DPWH

The ME of the contractor is directly under the supervision of the _____?

well packed in durable containers to avoid damages in transit, accompanied by a sample card filled up in detail and duly signed by the ME

The requisites in transporting samples of the laboratory is _____

Materials Engineer of the DPWH

Who has the power to recommend the acceptance or rejection of construction materials for use in the project based on test results?

asphaltene

It is a chemical composition of asphalt that gives color and hardness.

No. 200

The mineral filler which is used in the bituminous mix is passing sieve?

pothole patching

Cold mix asphalt is used in _____

Voids in Mineral Aggregates

VMA means

124ºC

The compaction temperature in molding the bituminous mixture specimen

163ºC

The mixing temperature of bituminous mix is

121ºC - 188ºC

The heating temperature of bituminous mix is

177ºC - 191ºC

The heating temperature of aggregates ranges from

240 kg per m3

The maximum absorption content of CHB

45%

The maximum moisture content of CHB

Standard Penetration Test

SPT means

Shelby tube

A tube sampler is used in sampling undisturbed sample

wax

Used in sealing undisturbed sample

Split spoon sampler

A tube sampler is used in sampling disturbed sample

Standard Penetration Test

It is a dynamic test used in the field to obtain rapid empirical results which can be used to estimate shear strength and bearing capacity

diamond bit

A type of coring bit used in rock coring

Certificate of Quality Control Assurance (submitted weekly)

CQCA means

1.01-1.04

The specific gravity of asphalt ranges from

cationic

The type of electron present in rapid curing emulsified asphalt?

fifteen (15)

How many group of three in – situ densities are required if the compacted volume of embankment laid was estimated to be 1,500 cu. m with a thickness of 200 mm per layer?

6% maximum under nominal stress

The allowable % variation in mass of deformed reinforcing steel is

0.06%

The maximum allowable % phosphorous content of a deformed and plain billet steel bar is

TENSILE STRENGTH YIELD POINT

GRADE 40 483 MPa 276 MPa

GRADE 60 621 MPa 414 MPa

GRADE 75 689 MPa 517 MPa

Tensile and yield strengths of steel bars?

clay content

Plasticity index is an indication of percent

air – dried condition

The condition of the soil to be tested in the laboratory compaction test is

Sand cone method

The method in the determination of density of soil in – place

sieve No. 10 retained No. 200

Air –dry sand used in the density apparatus is passing

surfacing materials

Which of the following items does not need CBR?

GRADING A – 12 spheres

GRADING B – 11 spheres

GRADING C – 8 spheres

GRADING D – 6 spheres

In abrasion test, the abrasive charge shall consist of cast – iron spheres or steel spheres.