Concrete Technology MCQ – Aggregate MCQ

131. The average specific gravity of coarse aggregate varies from

1. 2.6 to 2.8
2. 2.0 to 4.0
3. 2.0 to 2.9
4. 2.2 to 3.0

132. The minimum quantity of cement content needed in 1m³ of a reinforced concrete which is exposed to weather is (in kg)

1. 200
2. 250
3. 300
4. 350

133. A moist sand occupies a depth of 15 cm and when fully saturated it occupies 12 cm. Then the bulking of sand is

1. 25%
2. 12%
3. 10%
4. 15%

134. Batching in concrete refers to

1. controlling the total quantity of each batch
2. weighing accurately, the quantity of each material for a job before mixing
3. controlling the quantity of each material into each batch
4. adjusting the water to be added in each batch according to the moisture content of the materials being mixed in the batch

135. If in a concrete mix the fineness modulus of coarse aggregate is 7.6, the fineness modulus of fine aggregate is 2.8 and the economic value of the fineness modulus of combined aggregate is 6.4, then the proportion of fine aggregate is

1. 33.3%
2. 25%
3. 66.6%
4. 50%

136. Which of these statements are correct for bleeding of concrete leads?

1. Drying up of concrete surface
2. Formation of pores inside
3. Segregation of aggregate
4. Decrease in strength

1. Only i and ii
2. Only i
3. Only i and iii
4. Only ii and iv

137. How are concrete mixers specified?

1. by the number of cement bags used in a batch
2. by the nominal volume of concrete that can be mixed in a batch
3. by the volume of water used
4. by the volume of aggregate used

138. The concrete may attain its 100 percent compressive strength after

1. 28 days
2. 3 years
3. 1 year
4. 5 years

139. Following compounds can be used as accelerators except

1. CaCl₂
2. NaCl
3. CaSO₄
4. Na₂SO₄

140. Which of the following is not a method for curing high volume fly ash concrete?

1. Use of curing compounds
2. Water sprinkling
3. Ponding
4. Nitrogen purging