All Free Civil Engineering MCQs with Answers

• A. Capillary pores after evaporation
• B. Additional cementing compounds
• C. Higher aggregate strength
• D. Greater resistance to carbonation

Explanation: Excess mixing water eventually leaves the paste and forms capillary voids.

• A. 1.15
• B. 2.15
• C. 3.15
• D. 4.15

Explanation: Ordinary Portland cement has a specific gravity of about 3.15. This value is used in absolute volume calculations during concrete mix…

• A. Surface polishing
• B. Sudden impact loading
• C. Gradual compressive loading
• D. Chemical weathering

Explanation: The aggregate crushing value indicates resistance to crushing under a gradually applied compressive load.

• A. Improved cement hydration
• B. Delayed cement expansion
• C. Reduced aggregate absorption
• D. Segregation of the mix

Explanation: Over-vibration can drive coarse aggregate downward and bring mortar or water upward, producing segregation.

• A. Calcium hydroxide to form binding compounds
• B. Gypsum to form extra sand
• C. Coarse aggregate to form air voids
• D. Mixing water to form free lime

Explanation: Pozzolanic materials react with calcium hydroxide released during cement hydration.

• A. Decrease to zero
• B. Increase
• C. Remain exactly constant
• D. Change only during mixing

Explanation: A higher water-cement ratio leaves more capillary pores after evaporation, so permeability generally increases.

• A. Abrasion under rubbing
• B. Absorption of mixing water
• C. Sudden shock or impact
• D. Chemical attack by sulphates

Explanation: The aggregate impact value assesses how well aggregate resists sudden blows or shock.

• A. Stops completely
• B. Changes aggregate into cement
• C. Becomes independent of water
• D. Proceeds more rapidly at early ages

Explanation: Higher temperature generally accelerates hydration and early strength development.

• A. 10
• B. 50
• C. 100
• D. 1000

Explanation: Fineness modulus is calculated by adding the cumulative percentages retained on the specified sieves and dividing the sum by 100.

• A. Eliminates the need for cement
• B. Provides high early strength
• C. Prevents every type of shrinkage
• D. Makes aggregate grading unnecessary

Explanation: Steam curing raises the temperature and moisture available for hydration, allowing precast units to achieve useful early strength quickly.

• A. It prevents carbonation of concrete
• B. It increases the density of aggregates
• C. It controls the setting time of cement
• D. It provides most of the cement colour

Explanation: Gypsum is added to Portland cement to regulate the rapid reaction of tricalcium aluminate and prevent flash set.

• A. Constant temperature
• B. Specified compressive strength
• C. Maximum expansion
• D. Standard penetration

Explanation: Normal consistency is the water content that allows the Vicat plunger to penetrate the cement paste to a specified depth.

• A. Greater surface area and interlocking
• B. Lower specific gravity and absorption
• C. Higher cement content and fineness
• D. Greater elasticity and thermal resistance

Explanation: Angular and rough particles have greater surface area and interlock more strongly, increasing internal friction and water demand for the…

• A. Increase the specific gravity of cement
• B. Promote corrosion of embedded steel
• C. Prevent aggregate interlocking
• D. Eliminate cement hydration

Explanation: Chloride ions can break down the passive protective film around reinforcing steel and promote corrosion when sufficient moisture and…

• A. Resistance to aggregate crushing
• B. Resistance to cement setting
• C. Flexural tensile strength
• D. Elastic recovery after unloading

Explanation: The modulus of rupture is the flexural tensile strength obtained from a bending test on a concrete beam or prism.

• A. Initial setting time
• B. Cement fineness before mixing
• C. Exact water-cement ratio
• D. Uniformity and internal defects

Explanation: Ultrasonic pulse velocity helps identify variations in quality, cracks, voids and internal discontinuities in hardened concrete.

• A. Drying shrinkage
• B. Aggregate crushing
• C. Flash setting
• D. Loss of cement hydration

Explanation: More paste can lubricate aggregate particles and improve workability, but the larger volume of cement paste can increase drying shrinkage.

• A. Evaporation from an exposed surface
• B. Self desiccation during cement hydration
• C. Settlement of coarse aggregate
• D. Expansion caused by wetting

Explanation: Autogenous shrinkage results from internal moisture consumption during hydration, especially in low water-cement ratio concrete, which…

• A. To delay cement hydration in lower layers
• B. To increase the water-cement ratio gradually
• C. To ensure each layer is properly compacted
• D. To prevent all contact between adjacent layers

Explanation: Placing manageable layers allows vibration or other compaction to remove entrapped air throughout the depth.

• A. Stop hydration of the cement paste
• B. Decrease the total aggregate surface area
• C. Eliminate the need for compaction
• D. Increase the surface area requiring paste

Explanation: Smaller aggregate particles provide a greater total surface area, so more paste is needed to coat them and maintain comparable…