LAUSR

Abstract Ready-mixed concrete manufacturing consumes a lot of cement and generates millions of m3 of concrete sludge waste (CSW). We know that the CSW is heterogeneous and presents different chemical and physical properties. The present paper evaluates the influence of different CSWs on the properties of structural mortars by partially replacing cement by fine fractions of concrete sludge waste. CSW samples were collected in three different CBPs and 25% of cement was replaced by fine fractions of sludge – the same water/fines ratio was kept and additives were not added to them. The results showed that the heterogeneous features of CSWs influenced the produced mortars’ properties. Results at hardened state, with cement replacement by fine sludge waste, were close to those recorded for limestone filler-added mortars – values were within the ranges set by the standard for composite cement with filler. Results got closer as calcite content increased in the sludge samples.