Mechanical and durability characteristics of High Performance Concrete containing steel slag and crystalized slag as aggregates

The present research study was conducted in order to compare the mechanical properties and durability indicators of High Performance Concrete (HPC) using artificial aggregates such as steel slag and crystallized slag as coarse aggregate with HPC using natural limestone aggregates. Properties of fresh and hardened HPC were evaluated for three concrete mixtures using steel slag, crystallized slag and limestone aggregates. Ground granulated blast furnace slag (GGBFS) and silica fume (SF) were added as supplementary cementing materials. Water to binder ratio equal to 0.27 was maintained for all mixtures. Different mixtures were tested for mechanical strength at different ages, while durability indicators such as capillary absorption, water porosity, gas permeability and chloride ion diffusion tests were also carried out. The analysis of tests results showed that the mineralogy, morphology and strength of aggregates are significant factors affecting the compressive strength and durability of HPC. Rough surface texture of artificial aggregates, improved the bond between aggregates and hardened cement paste and better increased the strength of concrete.