Civil Engineering Materials and Construction

Subgrade Soil and Compaction

• Subgrade soil is well compacted under the controlled condition of optimum moisture content and maximum dry density.
• The percentage of asphalt in the mix is between 3 to 12 mass percent.

Seal Coat Application

• The rate of application of seal coat using cutback asphalt is 1.5-2 li./sq.m.
• The rate of application of seal coat using cutback asphalt can also be 2.0-3.0 li./sq.m.

Defective Works and Project Inspection

• Defective works in a project should be brought to the attention of the contractor by the Project Inspector through a logbook entry, progress billing deduction, inspection report, or site instruction.
• 15% to 50% of the payment is withheld on general items until the final acceptance of the project.

Construction Safety Procedures

• The side of deep excavations must be properly shored.
• All openings above ground level must be guarded.
• Operators and mechanics must be required to log in when operating equipment.
• Workers engaged in clearing must be protected from hazardous plants.

Project Implementation and Delays

• Causes of delay in project implementation include revision in plans, inadequacy of contractor's resources, and non-availability of construction materials.
• Rainy months predetermined in the area are not a cause of delay in project implementation.

Final Inspection and Project Completion

• After the final inspection of a reported 100% accomplished project, a turn-over ceremony is conducted in the field.
• If a project is started more than 8 months after the bidding, the contractor is entitled to claim for price adjustment.

Weather Conditions and Catch-up Plans

• The Philippines has two pronounced seasons, dry from November to April, and wet during the rest of the year.
• The catch-up schedule reflects the accomplishment-duration relationship.

Project Management and Contractor Disputes

• If a contractor continues to disregard agreed project plans and specifications, a recommendation should be prepared for termination of contract.
• If a contractor continues to disregard agreed project plans and specifications, the Project Engineer may also prepare for blacklisting of the contractor.

Materials and Construction

• Excavation of indurated rocks can be undertaken by ripper or bulldozer.
• The Plasticity Index (PI) required for Item 201, Aggregate Base Course materials, should not be greater than 6%.
• For a compacted pavement, the stability value in the Marshall Test measures the resistance to displacement.

Testing and Quality Control

• The flexural strength of concrete is considered satisfactory when the average strength of all sets of 3 consecutive strength test results equal or exceed the specified strength.
• The curve formed on a maximum dry density and optimum moisture content graph is a parabola.

Asphalt and Concrete Mix Design

• The single factor that determines the strength of concrete is the water-cement ratio.
• The design mix for concrete with fc at 28 days of 3500 psi is 4000 psi; 3010 psi; 3489 psi.
• The specific gravity of Portland cement must be 3.15.

Bituminous Concrete Mixes

• The most commonly used method in the design and evaluation of bituminous concrete mixes is the Marshall stability test.
• The role of application of prime coat before asphalt overlaying is to ensure bonding between the asphalt and the existing surface.

Timber Piles and Preservatives

• The minimum penetration of the preservative with the surface of the timber piles shall be 250 mm.
• The contractor shall submit in writing a job-mix formula for the mixture supported by the laboratory test data along with samples of resources of components and viscosity-temperature relationship to the Engineer for testing and approval at least one week.

Concrete Samples and Testing

• The concrete samples should be stored in a moist conditioned temperature within the range of 16C to 27C until the time of test.
• The mass % wear of soil aggregate used in cement/lime proportions should not be more than 45%.

Soil Stabilization

• Calcium Chloride is used in soil stabilized road surface due to its high property, i.e., it absorbs and retains water.
• The uniform rate at which the movable head of CBR machine tray is 0.07 in/min.

This quiz assesses your understanding of various concepts in civil engineering, including soil properties, compacting conditions, and seal coat application rates.