COMPRESSIVE STRENGTH OF LOW CEMENT HIGH FLY-ASH CONCRETE

This paper evaluates the effect of fly ash on the compressive strength development of the hardened concrete. Test results show that, compared with the Reference Mix which reached the required strength (2000 psi; 14 MPa) at 28 days, the concretes with the fly ash replacement reached the strength at 35 to 170 days, depending on the replacement percentage and the properties of fly ash. From the standpoint of concrete behavior, it was concluded that in lean concrete, the use of a large amount of fly ash, as replacement for both cement and sand, is highly beneficial.