78. Pick up the correct statement from the following :
A. Water enables chemical reaction to take place with cement
B. Water lubricates the mixture of gravel, sand and cement
C. Only a small quantity of water is required for hydration of cement
D. All the above
79. Higher workability of concrete is required if the structure is
A. made with cement concrete
B. thick and reinforced
C. thin and heavily reinforced
D. thick and heavily reinfored
80. Pick up the correct statement from the following :
A. Higher workability indicates unexpected increase in the moisture content
B. Higher workability indicates deficiency of sand
C. If the concrete mix is dry, the slump is zero
D. All the above
81. Internal friction between the ingredients of concrete, is decreased by using
A. less water
B. fine aggregates
C. rich mix
D. more water and coarse aggregates
82. Segregation is responsible for
A. honey-combed concrete
B. porous layers in concrete
C. surface scaling in concrete
D. all the above
83. The concrete mix which causes difficulty in obtaining a smooth finish, possess
A. segregation
B. internal friction
C. hardness
D. bleeding
84. The factor which affects workability, is
A. water content and its temperature
B. shape and size of the aggregates
C. grading and surface textures of the aggregates
D. all the above
Page 12 of 39