Mechanical properties study of metal slag and fly ash mixture as cement replacement in concrete

Abstract

Concrete is the largest amount of construction material produced in construction industry. The additional of alternative pozzolanic materials for example fly ash and metal slag were introduced as cement replacement in concrete. The additional of these alternatives pozzolanic materials will improve the quality and the durability of concrete. Three different samples of concrete were casted. Control sample with no alternative materials added, while sample A, B, and C, fly ash and metal slag were added in with different proportion to replace the cement content. Besides, X-Ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) were used to analyze the chemical compounds and the morphology of the concrete. In this study, XRF were used to determine the chemical compounds found in fly ash and metal slag. The oxidized metal slag will affected the mechanical properties of concrete. Moreover, compressive strength, water absorption capacity and density of concrete were inter-related. Compressive test, water absorption capacity test and density test of concrete were carried out to determine the physical and mechanical properties of concrete. Compressive strength of concrete is depends on the amount of voids and porosity presence in a concrete. The higher the amount of voids and porosity presence in a concrete, the higher the water absorption capacity, and this will results in lower density of the concrete. Therefore, compressive strength of concrete will be lower due to the presence of porosity. The compressive strength of concrete is increasing with the increasing of the curing age.