Influence of pozzolan from various by-product materials on mechanical properties of high-strength concrete

This paper presents experimentally investigated the effects of pozzolan made from various by-product materials on mechanical properties of high-strength concrete. Ground pulverized coal combustion fly ash (FA), ground fluidized bed combustion fly ash (FB), ground rice husk-bark ash (RHBA), and ground palm oil fuel ash (POFA) having median particle sizes less than 11 mu m were used to partially replace Portland cement type I to cast high-strength concrete. The results suggest that concretes containing FA, FB, RHBA, and POFA can be used as pozzolanic materials in making high-strength concrete with 28-day compressive strengths higher than 80 MPa. After 7 days of curing, the concretes containing 10-40% FA or FB and 10-30% RHBA or POFA exhibited higher compressive strengths than that of the control concrete (CT). The use of FA, FB, RHBA, and POFA to partially replace Portland cement type I has no significant effect on the splitting tensile strength and modulus of elasticity as compared to control concrete or silica fume concretes. This results suggest that the by-products from industries can be used to substitute Portland cement to produce high-strength concrete without alteration the mechanical properties of concrete. (c) 2006 Elsevier Ltd. All rights reserved.