Pengaruh Penggantian Sebagian Semen Dengan Bentonit Terhadap Kuat Tekan Beton

Indonesia is a develop country that built many buildings, so cement demand for construction is very high. For reduce cement using, needed pozzoland as cement substitution but can increase strength. On of pozzolands that available in great quantities in Indonesia is bentonite.This research about concrete strength with bentonite as pozzoland as cement substitution. Percentage of pozzoland as cement substitution are 0%, 2,5%, 5%, 7,5%, 10%, 12,5%, 15%, 17,5%, 20%.. The age of speciments test are 28 days.The result of this research are chemical composition in bentonite fulfill of condition as natural pozzoland, the lowest slump is 6.0 mm is obtained by 20% bentonite as substitution cement, the maximum slump value is 65.5 mm is obtained by 0% bentonite as substitution cement, slump value decrease along with additional bentonite percentage. The minimum concrete compression is 14.99 MPa obtained by 20 % bentonite as substitution cement and the maximum concrete compression is 26.53 MPa obtained by 7.5 % bentonite as substitution cement. Keywords: bentonite, slump, concrete compression