The Influence of Kaolin as an Additive on Concrete Compressive Strength

Kaolin is a clay soft, white mineral which can be found in nature and is known as clay stones. This research aimed to investigate the effect of using kaolin as an additive material toward compressive strength of concrete. This was qualitative experimental research which the object being a concrete K-350. The researchers planned K-350 based on the concrete standard for building structure four floors. The kaolin mixture used was at a percentage of 5%, 10%, and 15% of the cement weight according to the job mix formula for K-350 concrete quality. After 28 days, the resulting concrete samples were tested in the laboratory using a compressive strength testing machine. The results showed that the average compressive strength of kaolin 5%, 10%, and 15% were 27.27 MPa, 30.15 MPa and 24.48 MPa. The optimum result of the kaolin mixture was 15%. Based on the result, the researchers did not recommend applying kaolin as an additive material for building structure four floors.