EFFECT OF HOT CLIMATE ON SLUMP LOSS AND SETTING TIMES FOR SUPERPLASTICIZED CONCRETES

The results of a laboratory investigation of slump loss, setting times, and workability at low and high concrete temperatures for superplasticized concretes are presented. There was a substantial reduction in the intial and final setting times when there was a 16 deg F increase in the initial concrete temperature. Results of the slump-loss study indicated that there was adequate working time (2 to 3.5 hr) when a superplasticizer was used for concretes made at a temperature of 70 deg F (21.2 deg C). For the same concretes mixed at a temperature of 86 deg F (30 deg C), however, there was a considerable reduction in slump and available working time. (Author)