Effect of Metakaolin on the Physical Properties and Setting Time of High Performance Concrete

摘要

Kaolin native to Jilin Province was calcined at the constant temperature of 750°C for 4 hours to obtain the high pozzolanic metakaolin(A_(12)Si_2O_7). The effects of metakaolin (MK) on the static flow expansion of cement paste and the workability and setting time of concrete were studied with the content of 0, 5%, 10% and 15% by weight of cementitious material. The test results show that: when the dosage of superplasticizer is 2% by weight of cementitious material, the setting time of concrete shortens obviously and the slump and expansion decrease with the raising of MK content. When 5% of cement is replaced by MK, the setting time of concrete shortens by 5%; the slump and the slump flow decrease by 5.5% and 4.4% respectively.