Using Waste Materials in Durable Environmentally Friendly Concrete

Solid waste management is one of the major environmental concern all over the world. Big amounts of waste tires are generated each year and utilization of this waste is a big issue from the aspects of disposal of this amount of this waste, and health hazards. One of the recommended methods to utilize of this waste to be used as an ingredient of Portland cement concrete that could be used in concrete block paving, pedestrian blocks, highway sound walls, residential driveways, and garage floors. In this study, an experimental investigation has been performed using a waste rubber tires and bentonite in the concrete mix design. Rubber waste is used to replace fine aggregate in the concrete with different percentages (5, 20, 25, 30, 40%). Slump test are conducted to evaluate the workability of fresh concrete. Compressive strength of cubes at 7 days and 28 days are studied and compared with conventional concrete. The research work addresses the effect of using waste rubber tires and bentonite on durability of concrete. For this purpose, specimens were submerged in solution containing 50 g/l of NaOH and H₂SO₄, and according to the results it can be stated, that rubberized concrete can be used in to improve concrete durability. Based on the test results, the ideal percentage of mix which shows maximum compressive strength is identified. The optimal mix from the laboratory experimental investigation contained 20% waste rubber tires and 5% Bentonite replacement that exhibited a compressive strength of 33 MPa at 28 days.