Effects of Municipal Waste Ash and Fly-Ash on Strength and Stiffness of Eco-Cement Concrete

Abstract

In response to mounting ecological constraints, environmental regulations and the need for sustainable development, the construction industry continues to seek innovative materials, dubbed eco-materials, that are meant to reduce emissions of greenhouse gases and consume less energy during their production, utilize municipal and industrial wastes, and be recyclable, while maintaining the required structural integrity. Herein, studies on the potential use of Municipal waste ash (MWA) and Fly ash (FA) as a partial replacement of fine aggregate in eco-cement concrete and ordinary cement concrete are presented, motivated by the prevailing acute problem of waste disposal and management in developing countries. The eco-cement concrete was produced using eco-cement, which is produced from municipal waste ash and other materials. Compressive strength results reveal that replacement of fine aggregate with municipal waste ash of between 5% to 10 % produces eco-cement concrete of higher strength than that of the original unblended eco-cement concrete, and is thus seen as a likely profitable solution to the management of hazardous municipal waste heaps in developing countries, as well as a supplementary source of fine aggregate. It is generally observed that MWA is more effective and consistent in eco-cement concrete, while FA is more effective and consistent in ordinary cement concrete. For elastic stiffness, the general trend is that there is increase in eco-cement concrete compressive elastic stiffness at 28 days age with increased additions of MWA and FA in eco-cement concrete, attributable to the void filling effect of the additive. All in all, the results affirm the apt performance of eco-cement for eco-concrete production, and further permits the incorporation of MWA.

Keywords: Municipal solid waste; incinerator ash; Fly ash; Eco-cement; Eco-concrete