Properties of Sustainable Concrete with Processed Slag Sand

Conventionally natural sand is used as fine aggregate in manufacturing of concrete, whose availability is decreasing day by day. This study investigates the properties of concrete with alternative fine aggregate-processed slag sand. M55 grade concrete was designed with natural sand as fine aggregates. Natural sand was replaced by slag sand from 0 to 100% with an interval of 20. Constant workability of 90–110 mm slump was maintained at each replacement level by varying dosage of superplasticizer. Specimens were cast and cured for 7, 28, and 56 days. Compressive, split tensile, flexural, and shear strength were found apart from density, water absorption, sorptivity, and permeability of concrete. Microstructure of concrete was studied using SEM. Reduction in workability of concrete in terms of slump was observed with an increase in slag sand replacement percentage. Partial replacement of processed slag sand results in concrete with comparable mechanical properties and comparable durability. Optimum replacement was observed at 40–60%. Strength characteristics of concrete with complete replacement of natural sand by slag sand is comparable to natural sand concrete whereas it shows slightly lesser durability and porous structure. Hence, use of processed slag sand for partial replacement of natural sand in concrete can be recommended as a sustainable initiative.