Potential pozzolanic reactivity of recycled aggregates and waste powders as cement mortar component

Abstract

ABSTRACT In this study, the use of recycled fine aggregates and waste powders in mortar was discussed, in which the pozzolanic reaction and the effect on strength properties of the resulting mortar were experimentally investigated. Test results showed that the compressive strengths of mortars with fine recycled brick and tile particles were lower than those of the control mortar at age of 7 days in the range of 72–92%, but reached 82–98% at age of 90 days, respectively. Because of the cement reduction, the mortars with waste powder cannot reach the strength level of the control mortar, and the strength of the mortars decreased with the increase in the cement replacement ratio. The strength efficiency of cement in mortar with the waste powders mortars increases with the increase of waste powder replacement ratio at later ages (56 and 90 days). This may be interpreted by the waste powders, being composed of major acidic oxides, could trigger the pozzolanic reaction to provide additional strength gains for mortar.