The Compressive Strength of Concrete Containing Additive as Cement Reducer

Abstract

This paper discussed about the compressive strength of cylinder normal concrete and concrete containing additive as cement reducer, cement, sand, aggregate and water. The composition of control concrete were add with additive material called cement reduction. The methods of mixed design based on Indonesian Standard SNI-03-2834-2000. Composition of control concrete was 1 cement (100%): 2.4 fine aggregates: 3.1 coarse aggregates: 0.54 water. There were 3 mixed concretes designed: 1) 0.6cement reducer (0.6% of cement weight) 100% cement 2.4 fine aggregates: 3 coarse aggregates: 0.52 water.; 2) cement reducer 0.8% of cement weight and 100% cement (mix 0.8); 3) cement reducer 1% of cement weight and 100% cement (mix 1.0.). Concrete specimens were cylindrical with diameter of 15 cm and height of 30 cm. The results showed that the rate of compressive strength of control concrete with 0% cement reduction on 28 days tested was 32 MPa or 100%. The rate of compressive strength of concrete with 0,6%; 0.8%; 1%; cement reduction was 99%, 109%, and 104%respectively. The rate of weight of control concrete was 12.69 kg or 100%. The rate of weight of modified mixed concrete were 101%, 102%, and 102%.