Effect of fly ash and slag on properties of normal and high strength concrete including fracture energy by wedge splitting test: Experimental and numerical investigations

Abstract

The effect of supplementary cementitious material (fly ash and slag) on the properties of concrete was investigated at different ages starting from as early as 18 h in this paper. The tests covered concrete mix with a different amount of supplementary cementitious material (SCM). The effect of SCM on the properties of concrete (compressive strength, splitting tensile strength, modulus of elasticity, Poisson’s ratio and fracture energy) was investigated. Properties of concrete including fracture energy of concrete by wedge splitting test (WST) with different percentage of fly ash (FA) and slag were evaluated. For a mix with 50% slag, there was a decline in the values of compressive strength of concrete, splitting tensile strength, modulus of elasticity and fracture energy compared with a mix with 25% FA. The mix with 25% FA also had a higher fracture energy of concrete than the mix with 50% slag. The fracture energy decreased when FA and slag were added at all ages compared to the pure cement mix. A finite element (FE) model was developed and the results from the FE analysis were compared with the experimental work. A good agreement was achieved in terms of fracture energy and splitting load vs crack mouth opening displacement.