Durability Properties of High-Strength Concrete Containing Fly Ash, Dolomite Powder and Slag Sand

Abstract

Concrete is the most extensively utilized construction material worldwide. The production and demand for cement have seen significant growth, but this increased demand has raised concerns about its environmental impact within the construction industry. Concrete can be produced using alternative materials or substitutions for cement, fine aggregate and coarse aggregate, often utilizing waste materials. In this study, dolomite powder and fly ash used as a partial replacement for cement and slag sand is used as a 100% replacement to natural sand. Dolomite powder shares certain properties with cement, making it a cost-effective alternative that can enhance the strength of concrete. The disposal of fly ash is becoming a significant environmental concern due to its potential environmental hazards as a waste material. Using fly ash is not only cost-effective but also improves the workability, strength, and durability of concrete. Additionally, the use of slag sand not only contributes to environmental conservation but also enhances the structural strength and durability of concrete. The reason is the high tensile strength of slag. The durability tests on this project are water absorption, acid and alkali resistance tests. In these tests, an acid resistance test involves the use of 5% dilute sulfuric acid (H2SO4) by volume of water, while an alkali resistance test uses 5% sodium hydroxide (NaOH) by weight of water. These tests are conducted using M60 grade concrete mixtures, which incorporate partial replacements of cement with fly ash ranging from 0% to 10% by weight of cement, and dolomite ranging from 0% to 20% by weight of cement. Additionally, fine aggregate is replaced with slag sand in these mixtures.