Paper Details

While concreting in hot weather, both setting time and compressive strength are adversely affected. To prevent concrete from the adverse effects of hot weather, admixtures are usually incorporated in it. The objective of this paper is to investigate the effects of a retarding admixture (ASTM C 494 Type D) on setting time of cement pastes. The setting time tests were performed under three different curing conditions (temperature & relative humidity). The admixture was added to pastes made from three different types of cements. The test results revealed that the effects of admixture on setting time of cement pastes are dependent upon the type of cement and dosage of the admixture. It caused set retardation of the three different types of cements used, but with one type of cement it accelerated, the initial setting time and retarded the final setting time when dosages higher than 0.25% were used.