Chapter 6, Problem 6.33QP

The results of a laboratory experiment to evaluate the effects of a plasticizer are shown below.

a. Calculate the water–cement ratio in each of the three cases.

b. Using water reducer, how can we increase the compressive strength of concrete without changing workability? Refer to the appropriate case in Table P6.33.

c. Using water reducer, how can we improve workability without changing the compressive strength? Refer to the appropriate case in the table.

*Assume that the water content is above the saturated surface-dry (SSD) condition of the aggregate.

d. Using water reducer, how can we reduce cost without changing workability or strength? (Assume that the cost of the small amount of water reducer added is less than the cost of cement.) Refer to the appropriate case in the table.

e. Summarize all possible effects of water reducers on concrete.