Fresh and mechanical properties of concrete made of binary substitution of millet husk ash and wheat straw ash for cement and fine aggregate

Abstract

Abstract Now-a-days, many researchers use priceless industrial or agricultural products as the main raw material for the construction industry. However, these wastes are inexpensive and easily available everywhere to utilize for commercial purpose and also helpful in reducing the environmental pollution. This experimental study aimed to evaluate fresh (workability) and mechanical properties (density, permeability and split tensile strength, compressive and flexural strength) of concrete with 0%, 5%, 10%, 15% and 20% of millet husk ash (MHA) and 10%, 20%, 30% and 40% of wheat straw ash (WSA) to replace Ordinary Portland Cement (OPC) and sand respectively at conditions: a) concrete with MHA; b) concrete with WSA; and c) concrete with MHA and WSA. 525 concrete specimens were prepared with 1:1:2 mix proportions with 0.55 water/cement ratio and cured at 28 days. The increase of combined MHA and WSA contents to produce concrete decreased the workability of fresh concrete and decreased density and permeability of hardened concrete. Compressive strength, split tensile and flexural strength are increased with addition up to 15% of MHA and 30% of WSA combined. Same behavior is observed to compressive strength after chloride attack. Those results were better when compared to those of conditions a) and b). Therefore, it is possible to produce eco-friendly concrete with MHA replacing OPC and WSA replacing sand, individually or combined, which contributes to less environmental impact.