Eco-Friendly Mitigation of Alkali-Silica Reaction in Concrete Using Waste-Marble Powder

Abstract

With several countries halting coal combustion in favor of clean and renewable energy production, there is need for alternative mineral additions that can substitute for fly ash in concrete and bring about similar benefits. This study explores using waste-marble powder (WMP) as an economical and eco-friendly method for controlling the alkali-silica reaction (ASR). Reactive aggregates were used with WMP from the local marble industry (Pakistan) at various proportions ranging from 5% to 50% by cement mass. Strength activity index and thermal analysis tests were performed to examine the mechanical strength and hydration kinetics in mortar mixtures incorporating WMP. ASR expansion in mortar incorporating reactive aggregates decreased owing to WMP addition and was lower at 28 days than the limit of 0.20% for mixtures incorporating 30% or more WMP given in current standards. Whereas control specimens without WMP incurred surface microcracking due to ASR, specimens incorporating WMP remained intact. Scanning electron microscopy with energy disperse X-ray spectroscopy analysis showed reduction of ASR in specimens with WMP. Thus, it can be envisioned that using WMP as partial cement replacement creates an added-value application for an otherwise landfilled by-product and reduces harmful emissions from cement production, with the further advantage of mitigating ASR in concrete structures.