Effect of metakaolin and calcined kaolin on workability and rhelogical properties of self compacting concrete

In this study, the effectiveness of calcined impure local kaolin (CK) and commercially available high reactivity metakaolin (MK) on the workability and rheological properties of self-compacting concretes (SCCs) were investigated. Moreover, the compressive strength and ultrasonic pulse velocity of hardened SCCs were measured at the end of 28 days of water curing. After proper heat treatment, CK was utilized as a supplementary cementitious material. In order to observe and compare the influences of CK and MK, three replacement levels (0%, 5%, and 10%) were assigned. The SCCs with 0.35 water-to-binder ratio and 550 kg/m3 total binder content were designed for the testing. The workability tests applied were slump flow diameter, slump flow time (T50cm), V-funnel flow time, and L-box height ratio. For the rheological testing of fresh SCCs, ICAR rheometer was used to find the rheological parameters. The flow diameter of the SCCs were adjusted to be in the range of 700±20 mm. The test results indicated that the SCCs incorporating CK had lower loss of workability than MK incorporated ones. However, the hardened properties of SCCs with MK was better than control and CK included ones.