A Study of Properties of Wheat Straw Ash as a Partial Cement Replacement in the Production of Green Concrete

Abstract

Burning of wheat crop residue each year after harvesting is causing serious environmental degradation and severely effecting the quality of air. In proposed research properties of Wheat Straw Ash (WSA) and utilization of WSA as an environmentally friendly material is presented. Tests such as Blaine Air Permeability, X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) shows that WSA contain amorphous silica and has the potential to be used as a pozzolanic material, which is capable to replace cement partially. To determine the optimum percentage of WSA as a partial replacement of cement, a series of tests are conducted on 10%, 20% and 30% replacement of WSA by weight of cement. Slump and compaction factor test show a decrease in workability as the content of ash is increased, it is due to the large water absorption capacity of ash. One of the major finding is the high-water absorption capacity of the WSA which helps on a long term to reduce the shrinkage of concrete. Results show that the strength of concrete is decreased as the percentage of WSA is increased. The 10% replacement was relatable with the conventional concrete. A decrease in strength is noted for 20% and 30% replacement of cement by WSA.