26) The normal consistency of Portland cement is about

• (a) 10%
• (b) 15%
• (c) 20%
• (d) 25%

27) The initial setting time of rapid hardening cement should not be less than

• (a) 30 min
• (b) 1 hour
• (c) 4 hours
• (d) 8 hours

28) The final setting time of ordinary cement should not be more than

• (a) 2 hours
• (b) 4 hours
• (c) 8 hours
• (d) 10 hours

29) The addition of pozzolana to Portland cement causes

• (a) less heat of hydration
• (b) increase in shrinkage
• (c) decrease in permeability
• (d) all of the above

30) The rate of hydration and hydrolysis of cement depends upon its

• (a) soundness
• (b) fineness
• (c) setting time
• (d) tensile strength