BCE Construction & Building Materials 2

Question 1

Which admixture is added to concrete to significantly reduce the water-cement ratio without losing workability?

Accepted Answer

Superplasticizer

Answer

Superplasticizers (high-range water reducers) allow a 20-30% reduction in water content while maintaining workability.

Question 2

What is the primary purpose of curing concrete after placement?

Accepted Answer

To maintain moisture for continued hydration

Answer

Curing keeps concrete moist and at a suitable temperature so that cement hydration continues, developing strength and durability.

Question 3

Structural steel used in US construction is most commonly specified under which ASTM standard?

Accepted Answer

ASTM A36

Answer

ASTM A36 is the most widely used structural carbon steel standard, with a minimum yield strength of 36 ksi.

Question 4

What does the term 'modulus of rupture' measure in timber or concrete beams?

Accepted Answer

Flexural tensile strength

Answer

Modulus of rupture (MOR) is the maximum fiber stress at failure in a bending test, representing flexural tensile strength.

Question 5

Which type of brick is most resistant to efflorescence due to its low water absorption?

Accepted Answer

SW (Severe Weathering) grade brick

Answer

SW grade brick has the lowest water absorption (≤17%) and is designed for severe weathering conditions, reducing salt migration and efflorescence.

BCE - Bachelor of Civil Engineering Practice Test