Sustainable Reinforced Prestressed Alkali-Activated Concrete Beams Using Industrial Wastes: An Experimental Investigation

Abstract

In an era where the sustainability of the construction industry is of prime importance, alternatives to cement are a matter of urgency. In the present time, Alkali-Activated Concrete (AAC) being a widely researched topic, offers a viable alternative to cement concrete as it has the potential to utilize industrial wastes as a source material. The current study delves into assessing the impact of prestressing force on both, reinforced AAC and reinforced ordinary cement concrete (OPCC) beams. Industrial wastes that serve as primary constituents for AAC include slag and fly ash, which, in the present investigation are activated using sodium-based activators. The concrete was developed using ambient curing with a compression value of 40 MPa to achieve sustainability. Analysis of deflection, load-carrying capacity and failure characteristics were conducted on the reinforced concrete beams in prestressed and un-prestressed states, encompassing both, reinforced AAC and reinforced OPCC beams. In comparison to reinforced AAC beams, OPCC beams had 18.9% higher strength in flexure, but the deflection was 53.3% higher for AAC beams with rebars. In prestressed condition, the reinforced OPCC beams had 22.5% more load-carrying capacity as compared to reinforced prestressed AAC beams, though reinforced prestressed AAC beams had 26.2% more deflection as compared to reinforced OPCC beams. Hence, sustainable reinforced concrete beams can be manufactured from industrial waste, having very good flexural behaviour and load-carrying capacity.