MATERIALS ENGINEER PART 2 (600)

What is the sample for compressive strength determination of a structural concrete?

concrete cylinder sample

What is the test to determine the consistency of concrete?

Slump test

What is the length required for RSB sample for quality test?

1.0 m/10,000 kg/size/shipment

How many samples should be taken for every 75 cu.m fresh concrete?

1 set consist of 3-pcs sample

What is the required size of test specimen for G.I. sheets?

3 pcs-60 mm in 1 sht/100 sheets

What kind of paint that has a reflectance or beads?

Reflectorized Paint

What is that construction material that has a property of being a dark brown to black cementitious material in which the predominating substance is

bitumen?

asphalt

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

24 hours

What is the rate of application of bituminous tack coat?

0.2 to 0.7 L/sq.m

What is the penetration grade of blown asphalt?

0 to 30 penetration grade

What kind of sample is taken for flexural test?

Concrete beam sample

What are the tests needed for the 2.650 cu.m Item 201 (Aggregate Base Course)?

CBR, abrasion, GPCD

How many grading tests are required for a 3,200 cu.m selected borrow topping (Item 104)?

3 grading tests

As a materials Engineer, what will you recommend if you find out that the materials to be used as Item 200 if finer than the required materials?

blend Item 200 with coarser materials

What is the standard specification for LL and PI of Item 201?

maximum of 25% and maximum of 6% respectively

What is the CBR requirement for Item 201?

80% maximum

What asphalt is used for sealing weaken plane joint of concrete pavement?

Blown Asphalt

What is Item 311 of the DPWH Specification (Blue Book)?

Portland Cement Concrete Pavement

What is the machine used for abrasion test?

Los Angeles Abrasion Machine

How to determine the degree of compaction of Items 104, 200, & 201?

by Field Density Test

What is the formula in obtaining the value of PI?

Liquid Limit minus Plastic Limit

What are the other terms for sieve analysis?

Grading Test, Particle Size Distribution Test, Mechanical Analysis

What is the degree of compaction of the soil if the wet density is 2,200 kg/m

3

, with an actual moisture content of 10.2% and a maximum dry density of

1,960 kg/m

3

?

101.23%

How many concrete cores shall be taken for one (1) kilometer concrete pavement?

5 holes/km/lane

What is the moisture content of the soil having an original weight of 162.5 grams and an oven – dried weight of 138.2 grams?

17.58%

If the group index of a soil is high, what indication does it mean?

the soil is clayey

As a Materials Engineer, how can you determine that the sample placed in the oven is already oven – dried?

if the sample reaches its constant weight

In oven drying a sample for test, what temperature shall be maintained?

110 ± 5

o

C

Why is it that cooling an oven dried sample before weighing is advisable?

because it can affect its weight

What is the difference between hygroscopic moisture content from natural moisture content?

hygroscopic moisture content is the moisture content of an air- dried sample while natural moisture content is the moisture content of the

original sample from the field.

For how many bags of cement does a 10 kgs. sample represents?

2000 bags

For 15, 000 kgs RSB, how many samples shall be submitted for Quality Test?

2 pcs – 1 m sample

An admixture is being introduced to the fresh concrete mixture for heavily reinforced concrete structure using a pumpcrete to pump out the fresh concrete

mix, what admixture should it be?

Superplasticizer

What is the use of blown asphalt?

as joint filler and water proofing

What asphalt is commonly known as hot asphalt or penetration grade asphalt?

Asphalt Cement

How many days does the sample for Immersion – Compression Test be soaked in water?

4 days @ 50

o

C

If ductility test is for asphalt, _____ is for cement? Consistency

Magnesium Oxide, Insoluble Residue, Loss on Ignition

Paint is composed of _____

35% vehicle, 50% pigment, 15% beads

What is the size of tamping rod used in tamping concrete sample?

16 mm Ø and 610 mm long with hemispherical tip

What is the temperature to be maintained when curing sample after its initial curing?

23

o

C ± 1.7

o

C

Concrete cylinders are cured and ready for test. Temperature between 63°F to 85°F are permitted for a period not to exceed _____ hours immediately

prior to test if free moisture is maintained on the surface of the specimen at all times.

three (3)

The molds of specimen not to be transported shall be removed after initial curing of _____ hours and should be cured to the standard curing temperature

of 73.4 °F ± 3°F

Twenty-four (24)

High plasticity index means _____ of a soil?

high degree of compressibility

Sample to be used for liquid limit and plastic limit tests should pass to what sieve?

No. 40 (0.425 mm)

What compaction rammer shall used if the specs given for Moisture – Density Relation Test (MDR) is T – 180?

4.54 kg with 457 mm drop

A bean mold measuring 6” x 6” x 20 is to be used for sampling concrete, how many blows/tamps per layer shall be applied?

60 blows/layer

If asphalt mix having a weight of 3,020g and an aggregate weighing 2,865.98g, what is the % asphalt by weight of mix?

5.10%

What is the material used for Bituminous Prime Coat?

Cut-back asphalt

In Item 303, application of cover aggregates shall be evenly spread over the surface at the rate of approximately _____?

0.004 to 0.007 m

3

/m

2

Applying the tolerance of 0.4% for asphalt content to your answer in prob. 47, what is the acceptable range of asphalt content?

4.7% to 5.5%

An embankment having a PI of 30%, LL of 40% and GI of 0, what is the degree of compaction for this kind of soil?

95% degree of compaction

The minimum cement factor for concrete Class “A” is 9 bags/cu.m, how about for concrete Class “B”?

8 bags/ cu.m

Quality control testing in a DPWH project is the responsibility of the_____?

Contractor

As Materials Engineer, when is the right time to start sampling and testing aggregates?

Once the source is identified

The minimum compressive strength for concrete Class “P” is 5,000 psi, what is the minimum compressive strength for concrete Class “C”?

3000 psi

The volume of concrete mixer per batch shall not exceed the mixer’s nominal capacity in cu.m as shown on the manufacturer’s standard plate on the

mixer, except that an overload up to _____ percent above the mixer’s nominal capacity may be permitted provided concrete test data for strength,

segregation, and uniform consistency are satisfactory, and provided that no spillage of concrete takes place.

Ten (10)

Where do we take additional cores when the measurement of any core taken from pavement is deficient in thickness by more than 25 mm?

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

Under what climatic condition do we use lower penetration grade or hard asphalt?

hot climate (cold climate – higher penetration grade or soft asphalt)

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

Materials test results/reports

Penetration test is for asphalt: cement is to _____?

consistency

Slump test is a very important test in fresh concrete to determine _____?

consistency of concrete

How many samples should be taken for an asphalt mix for each full day’s operation?

at least one but not to exceed three samples

The thickness of asphalt core using a caliper is based on how many measurements?

four (4)

The thickness of concrete core using a caliper is based on how many measurements?

nine (9)

Failed samples do not necessarily mean that the structure it represents is defective, why?

may be the sampling is incorrect

The specification calls for a 1: 2:4 concrete mix. In a one bagger mixer, which of the following amount of water is most likely required for the mix?

20 liters

The spot test on asphalt is used to determine ______.

overheating during the process of manufacture

How many samples shall be submitted for test if 315 pails of flat wall enamel paint are to be used in the project?

four (4) pails

Aggregate Sub – base course has a volume of 5, 000 cu.m and to be laid in a 15cm compacted depth. How many samples shall be submitted for CBR test

and for sieve analysis?

2 samples for CBR and 17 samples for sieve analysis

How many samples shall be submitted for quality test if 60 tons of Bituminous Prime Coat is to be used in the project?

Two (2) samples

How many compaction tests shall be conducted for Item 201 having a volume of 8,250 cu.m?

Six (6) compaction tests

What composed of Materials Quality Control Monthly Reports?

Summary of field tests and status of test

What is the required mixing of mortar for Item 505 (Stone Masonry)?

1 part cement and 2 parts sand by volume with sufficient water

What is the required mixing of mortar for Item 500 (Pipe Culverts and Storm Drains)?

1 part cement and 2 parts sand by volume with sufficient water

Before the project starts, the materials Engineer or the technician must have a program on how many samples for each item of work should be tested

based on the minimum testing requirements. What program or report is this?

Quality Control Program

If sample splitter is not available for use in reducing samples for test, what is the alternative way of reducing sample for testing size?

apply quartering method and get two opposite sides as sample

The road will not be opened to traffic until test specimens molded and cured have attained the minimum strength requirements. If such tests are not

conducted prior to the specified age the pavement shall not be operated to traffic until _____ days after the concrete was placed.

Fourteen (14)

As the work progresses, the Materials Engineer should know how many sample has been submitted and tested and how many samples are to be

submitted, in other words the ME must refer to what report so that he/she may be updated on the balance and on file quality test of the construction

materials being used in the project?

Status of Test

It is the minimum moisture content at which the soil can be molded without breaking or crumbling up to 1/8” (3.2 mm).

Plastic Limit

The _____ is expressed as the moisture content corresponding to 25 blows.

Liquid Limit

The concrete has been tested for consistency by the use of a slump cone with base and tamping rod. After the test, the height of concrete measured is 178

mm. what is the slump of the concrete?

127 mm

What is the rate of revolution per minute of an abrasion Machine used for testing the mass percent of wear?

30 – 33 rpm

If the design of concrete mix has the following corrected batch weights: cement = 40 kgs, fine aggregates = 65 kgs, coarse aggregate = 115 kgs, and water

= 15 liters. What is your actual batch weights for 1 cu.m Class “A” concrete?

360 bags of cement; 585 kgs of fine aggregates; 1035 kgs coarse aggregates; 130 liters water

After the soil has been tested in an Abrasion Machine, the mass % of wear computed is equal to 21%. If this material is for Item 201, does it pass the

DPWH specs?

Yes, because the specs is 50% maximum

Quality Control Assurance Report should be submitted every _____?

week

One of the duties of Materials Engineer is to see to it that all the construction materials be tested:

before it is incorporated into work

What is the maximum depth or roadway embankment per horizontal layer in loose measurement?

200 mm loose measurement

Why is it that 6 samples are needed for quality test of concrete masonry?

3 samples for compressive strength and 3 samples for absorption

Sample submitted for test should have a tag bearing the name of the project, the quantity represented, kind of sample, original source, who sampled and

who submitted it, the date sampled and date submitted and etc. What is the common name of that tag for you as Materials Engineer?

Sample Card

Sample Card

If course aggregate like embankment is to be placed in layers, how many layers should a 40 cm thick Aggregate Base Course is placed?

Three (3)

The ME should always be alert of his schedule with regards to the number of days of a quality test that takes place. Since not all construction materials

can be tested just for a day or even a week so, what is the lead time should he consider for a quality test of a cement sample? Answer: One (1) month

92. CBR Sample for test has been compacted but it should be soaked for how many days before testing?

Four (4)

If sieve analysis and plasticity test are used for Soil Classification, what test that its result be used in field density test?

Compaction Test or Moisture Density Relation Test

Heavy rains occur the night before prior to your scheduled field density test, are you going to pursue your schedule? Why?

No, because the moisture content is high and can affect the result

Checking the gradation of composite aggregates and asphalt content of asphalt mix can be done by what test?

Extraction Test

What is the device used in testing for liquid limit test?

liquid limit device with grooving tool

What apparatus is used in plastic limit test?

glass plate

How long does a vibrator be inserted in a concrete mix?

not to exceed 15 seconds at 50 – 60 cm interval

Along the slope of high embankment _____ is provided as an erosion control measures and also to improve the stability of the slope.

Berm

In soil and sub – surface explorations for flood control design of foundation condition, a soil sample was taken for field and laboratory tests. The test

required for soil was taken, except

specific gravity, abrasion, water content, Atterberg Limits, gradation, compaction, relative density

Structure crossing above such covered underground drainage conduit shall be laid at least _____ above the top of the conduit.

1.0 m, 0.5 m, 1.5 m, 2.0 m