Materials Engineering Review Set One

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Questions and Answers

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

Depth of soil layer

Which of the following bituminous materials is best recommended for sealing weakened plane joints?

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

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

Segregation

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

20 liters Signup and view all the answers

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

3 layers over the full width of 4.5 m Signup and view all the answers

As a 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 Signup and view all the answers

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 Signup and view all the answers

Bituminous concrete mixes contain asphalt by weight equivalent to what?

5 to 8% Signup and view all the answers

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

Test of concrete pipes samples Signup and view all the answers

Where do we take additional cores when the measurement of any core taken from the 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 Signup and view all the answers

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 What is the resulting Index of Retained Strength? Does it meet the specification requirement of Item 301, Bituminous Concrete Surface Course?

Index of Retained Strength or IRS = Wet stability x 100 IRS = (1,000 Kpa/2,000 Kpa) x 100 = 50% No, the resulting IRS here is only 50% while the resulting IRS here is only 50% because the specification is 70% minimum while the resulting IRS here is only 50%. Signup and view all the answers

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

Contractor Materials Engineers Signup and view all the answers

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

Before the course materials are incorporated in the project Signup and view all the answers

The spot test on asphalt is used to determine what?

Overheating during manufacture Signup and view all the answers

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

Hot climate Signup and view all the answers

Sampling of the freshly mixed concrete should be taken on the ___ batch discharge of the transit mixer?

Middle Signup and view all the answers

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 sub-base course?

Geotextiles Signup and view all the answers

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

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

Materials Test Reports Signup and view all the answers

In testing concrete cylinder samples, 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 Signup and view all the answers

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

Higher rate Signup and view all the answers

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

Pneumatic-tire roller Signup and view all the answers

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

Pulverizing of the aggregate or displacement of the mixture Signup and view all the answers

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 Signup and view all the answers

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

150mm x 150mm or 100mm diameter full depth Signup and view all the answers

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 Signup and view all the answers

What is the sampling requirement for paving concrete for every 75 cu.m. or fraction thereof?

One (1) set (consisting of 3 pcs.) concrete beam sample Signup and view all the answers

In testing bituminous beam samples for Immersion-Compression Stability, the sample is soaked in a water bath for _ days or _ hours.

4 days or 96 hours Signup and view all the answers

Given: Wt. of dry aggregate = 950g Wt. of asphalt = 50g What is the % of asphalt by weight of total mix?

Wt. of total mix = wt. of dry aggregate. + wt. of asphalt = 950 g + 50 g = 1,500 g Thereof: (50 g / 1,000 g) x 100 = 5% Signup and view all the answers

Does the percent asphalt in problem #29 meet the required specification for percent asphalt in bituminous mixes? Why?

True Signup and view all the answers

If the actual percent asphalt in problem 30 is 5% and the percent asphalt in a job-mix formula is 5.6% did it pass the required tolerance? Why?

False Signup and view all the answers

Which is not the duty or responsibility of a materials engineer?

Quantity of construction material Signup and view all the answers

Problems regarding the quality of construction materials shall be reported directly by the contractor's materials engineer to the ___.

DPWH Materials Engineer Signup and view all the answers

How many sets (consisting of 3 pcs. cone, cylinder per set) Reinforced Concrete Culvert Pipes (RCCP) are required in a 300 pcs. cylinder sample?

12 Signup and view all the answers

Study Notes

Materials Engineers Review Notes - Set One

The standard penetration test (SPT) measures the depth of soil layer.
Joint filler asphalt (hard asphalt or blown asphalt) is best for sealing weakened plane joints.
Segregation is the main problem with wrong concrete conveying practices.
20 liters of water is usually required for a 1:2:4 concrete mix in a one bagger mixer.
Pavement width 3.5m and shoulder width 0.5m on each side: sub-base and base courses (300mm combined thickness) should be spread and compacted in 3 layers over 4.5m width.
500 square meters is a recommended trial section area for checking material suitability and equipment efficiency for Item 310 Bituminous Concrete Surface Course.
For 7500 cu.m. of Item 201 material, 25 grading and 25 plasticity tests are needed.
Bituminous concrete mixes contain 5-8% asphalt by weight.
Quality of factory-produced reinforced concrete pipes is best established through testing of concrete pipe samples.
Additional cores are taken when pavement core thickness measurement is insufficient and deviates more than 25mm. Taken at least 5m intervals parallel to centerline.
Immersion-Compression test results (Dry stability = 2000 Kpa, Wet stability = 1000 Kpa) yield an Index of Retained Strength (IRS) of 50% which does not meet the specification requirement of Item 310.

Materials Engineers Review Notes - Set Two

Quality control testing in DPWH projects is the responsibility of the contractor's materials engineers.
Aggregate sampling and testing should be conducted before incorporation into the project.
Spot tests on asphalt are used to detect overheating during manufacturing.
Lower penetration grade (hard asphalt) is recommended for hot climates, while higher grades are for colder climates.
Sampling of fresh concrete is best taken at the middle of the batch discharge from the transit mixer.
Geotextiles are an effective and affordable method for stabilizing soft, unstable soils before subbase construction.
Concrete specimens in a 6"x6"x12" beam mold need 63 roddings per layer.
Materials test reports are the basis for accepting or rejecting construction materials.
Constant rate of concrete cylinder sample loading should be within 0.14 – 0.34 MPa per second.
Pneumatic tire rollers are for initial (breakdown) rolling of bituminous mixtures, followed by tandem steel rollers for final rolling.
Bituminous mix rolling should stop when excessive pulverizing or displacement of the mixture.
95% minimum density of laboratory compacted asphalt samples is needed.
Asphalt core samples must be extracted using a saw or core drill to a minimum dimension of 150mm x 150mm or a 100mm diameter.
The surface of the bituminous mixture should be tested using a 3m straightedge with maximum variation tolerance of 20mm.
The average of 4 measurements is used for thickness measurement of asphalt core specimens.

Materials Engineers Review Notes - Set Three

Bituminous Concrete Surface Course (Item 310) is comprised of aggregates, filler, and asphalt.
The aggregates, filler, and asphalt in Item 310 Bituminous Concrete Surface Course should comprise 92-95% by weight.
Asphalt in Item 310 Bituminous Concrete Surface Course should comprise 5-8% by weight.
Job-mix formulas can be used to precisely determine asphalt percentages.
Two common asphalt types are tar and petroleum asphalt used in bituminous concrete surfaces.
Asphalt cements are produced in different viscosity grades (e.g. 200/300, 120/150, 85/100), while cutback asphalts mix asphalt cement with solvents.
Emulsified asphalts blend asphalt cement with water and emulsifying agents, classified as cationic or anionic based on their charge properties
Asphalt cement (AC) is a common bituminous material used in Item 310.

Materials Engineers Review Notes - Set Four

Nuclear density gauges (NDGs) are radioactive-material-containing instruments used for moisture content and compaction control in asphalt road construction.
Pundit ultrasonic concrete testers evaluate concrete quality non-destructively through detection of voids, cracks, and other defects.
Benkelman Beam and Deflection Logger measures pavement deflection caused by vehicle loads, used in road design and evaluation.
MERLIN road roughness measurement devices are used to assess roadway surface roughness/profile and derive a roughness index (IRI).
Rebar locators identify embedded metal elements within concrete before cutting or drilling.
Falling weight deflectometers measure differential deflections between concrete pavement joints and aid overlay design, estimating remaining life, and modulus of existing slabs.
Dynamic cone penetrometers (DCPs) are used for rapid in-situ structural property measurement from unbound granular materials.
Test piling is one method to determine casting length for bridge pile construction.
High spots over 15mm in a 3-meter straight edge on concrete pavements should be removed.

Materials Engineers Review Notes - Set Five

Steel reinforcing bars placed along longitudinal joints to restrain slab movement are called tie bars.
DPWH-accredited labs are authorized to test materials used in DPWH projects.
At least one to three core samples are extracted for each full day's operation to measure thickness and density of aggregate and asphalt mixtures.
Soils are classified based on grain size distribution and plasticity characteristics.
Thickness determinations for 1km concrete pavements often require around 5 cores per lane.

Materials Engineers Review Notes - Set Six

Portland cement concrete pavement is designated as Item 311 in DPWH Specifications.
Average strength of concrete samples representing the concrete area should be at least 85%.
Lumber is well-seasoned when its moisture content is between 12-18%.
Soils can be classified based on their grain size distribution and plasticity.
For 1km of concrete pavements, a minimum of five cores per lane are necessary for thickness determination.

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Description

This quiz covers essential topics in materials engineering, including the standard penetration test, concrete mix specifications, and bituminous concrete details. It aims to reinforce understanding of practical applications and guidelines in constructing and testing materials. Ideal for engineers and students preparing for examinations or reviewing core concepts.