Investigation of the effect of the coal wastes on the mechanical properties of the cement-treated sandy soil

Owing to the environmental pollution of industrial waste materials and the consideration of pozzolanic materials of the coal wastes (CW), the availability and economic cost of its combination with cement, these materials can be utilized for soil stabilization. In this investiga2tion, CW was used as an additive material to improve the properties of cement sand. For this purpose, different tests including standard Proctor, unconfined compressive strength, indirect tensile strength, ultrasonic pulse velocity, pH, and SEM are performed on the Babolsar sand containing 0%, 5%, 10%, 15%, and 20% coal waste (by weight of cement) with 3% and 6% of cement (by dry weight of the used sandy). Samples were cured for 14, 28, and 60 days. The results of this study indicate that the addition of optimum amount of CW (5%) at 28 and 60 days improves the mechanical characteristics of samples containing 6% cement. However, for samples containing 3% cement, the replacement of cement with CW constantly reduces mechanical properties. (C) 2019 Elsevier Ltd. All rights reserved.