Adding granite dust as paste replacement to improve durability and dimensional stability of mortar

Abstract

In a recent study by the authors, it has been found that the addition of granite dust (GD) as paste replacement (addition of GD to replace an equal volume of cementitious paste with the water/cementitious materials ratio kept constant) to decrease the cementitious paste volume in mortar offers substantial benefits in cement content reduction (and thus carbon footprint reduction), waste utilization, strength improvement and microstructure densification. In this study, the authors extended the research program to evaluate the effects of adding GD as paste replacement on the durability and dimensional stability of mortar. A series of mortar mixes with varying GD volume and water/cement ratio but similar workability achieved by adjusting the superplasticizer dosage were made for mini slump cone test, carbonation test, water absorption test and drying shrinkage test. The test results revealed that adding GD as paste replacement could substantially improve the carbonation and water resistances, reduce the ultimate shrinkage strain and shrinkage rate, and at the same time, reduce the cement content by up to 25%.