Properties of sustainable self-compacting concrete incorporating discarded sandstone slurry

Sandstone waste generated during the cutting and polishing process destroys the atmospheric condition when it is dumped along roadside, water bodies and landfill. The present investigation aims to utilize sandstone slurry (SS) as a partial replacement to portland pozzolana cement (PPC) in self-compacting concrete (SCC). Sandstone slurry was characterized by chemical composition, mineral phases, specific gravity, density, particle size distribution and scanning electron microscopy test as primary investigation. Afterwards, five replacement percentages (0, 5, 10, 15 and 20) of sandstone slurry by weight of portland pozzolana cement were assessed for their fresh and hardened properties. Scanning electron microscopy and fourier transform infrared spectroscopy were also conducted. Microstructural study confirms that the sandstone slurry did not influence the cement hydration, and the workability was decreased by the particular shape and surface texture of the sandstone slurry. To achieve the target workability, water to cement ratio was kept high and the dosage of superplasticizer was increased. This phenomenon validates increment in permeable voids and water absorption, reduced density and strength decrement of the self-compacting sand stone slurry concrete in comparison to the control concrete mix. The results point out the possibility of utilizing sandstone slurry (up to 15%) in self-compacting concrete, applicable for narrow and congested reinforcements, as well as in general structural works as a green and sustainable building material. This work discovers sandstone slurry as a sustainable substitution to portland pozzolana cement in the production of self-compacting concrete by minimizing the use of raw material and avoiding the environmental hazards created by the uncontrolled dumping of the sandstone by-products. (c) 2020 Elsevier Ltd. All rights reserved.