Effects of pre-wetting aggregate on the properties of mortars made with recycled concrete and lightweight aggregates

Abstract

This paper examines the suitability of partially replacing natural aggregate, sand, (NA) with recycled concrete
aggregate (RCA) or lightweight aggregate (LWA) in mortars, under the hypothesis that pre-wetting
aggregates would produce improvement in mortar properties. Fresh mortar properties such as density, entrained
air content, consistency and heat of hydration, as well as hardened mortar properties such as dry density,
compressive and flexural strength, and dimensional instability at 0% and 100% saturation were determined.
The results show that mortars made with natural aggregate (75%) and recycled concrete aggregate
(25%) have similar properties to mortars made with only natural aggregate (100%) and that pre-wetting the
aggregates does not influence the properties of mortars significantly. Therefore, partial replacement with recycled
concrete aggregate is a viable alternative for producing mortar.
Keywords: pre-wetting, recycled concrete aggregate, lightweight aggregate, mortars, sustainability.