Effect of artificial slag and fly ash aggregates on fracture and permeability properties of concretes

This study presents an experimental investigation on the effect of artificial aggregate utilization on the fracture and permeability properties of concretes. For this, two types of artificial aggregates, namely, artificial fly ash aggregate (AFA) from cold bonding agglomeration process of fly ash and Portland cement and artificial slag aggregate (ASA) from cold bonding agglomeration process of ground granulated blast furnace slag and Portland cement, were replaced with natural aggregate as coarse aggregate. Moreover, to investigate the influence of water-to-cement ratio, three different water-to-cement ratios of 0.35, 0.45, and 0.55 were considered in the concrete production. The concretes were tested for the mechanical properties in terms of as compressive strength, modulus of elasticity, and splitting tensile strength, net flexural strength, and fracture energy. They were also tested for permeability properties such as water sorptivity, water penetration, gas permeability, and resistance to chloride ion penetration. The test results were also analyzed by means of statistical technique, namely, GLM-ANOVA. It was found that the use of cold bonded fly ash and slag aggregates were very effective on the performance characteristics of concretes depending mainly on w/c ratio. Keywords: Artificial aggregate; Cold-bonding pelletization; Fracture behavior; Permeability.