Influence of recycled concrete, marble, glass, and limestone powder, and utilization ratios on the compressive strength and alkali–silica reaction performance of mortar mixtures

Abstract

Concrete, an indispensable cornerstone of the construction industry, presents a formidable environmental challenge owing to the substantial carbon dioxide (CO2) emissions incurred during the production of cement. However, in light of the construction sector’s vital economic and social contributions, it becomes imperative to harmonize it with environmental preservation. The concept of sustainability emerges as a paramount principle, addressing pressing issues such as the escalating depletion of non-renewable resources and the imperative need for resource conservation to secure a sustainable legacy for future generations. In this particular context, the prudent utilization of sustainable materials stands out as a pragmatic approach to ameliorate the adverse environmental impacts inherent in cementitious systems, while concurrently enhancing the structural strength and durability of constructions. The subject of this study is centered on the strategic incorporation of recycled concrete powder (RCP), marble powder (MP), glass powder (GP), and limestone powder (LP) as viable substitutes for traditional cement, at varying rates of 25%, 30%, and 35%, with the overarching goal of augmenting sustainability in construction practices. The outcomes of the experimental investigation unveiled significant insights. The inclusion of these waste powders yielded a noteworthy maximum reduction of 44% in compressive strength, albeit it necessitated a maximum increase of 16% in the application of admixtures. Nevertheless, a crucial advantage emerged in the substantial reduction, to the tune of 72%, in the deleterious alkali–silica reaction. Moreover, in terms of workability, while the control mixture experienced a 20% reduction in flow value after 60 min, mixtures infused with waste powders showcased a range of flow value reductions spanning from 23 to 40%. In summary, the study emphasizes that the replacement of conventional cement with waste powders, despite causing acceptable adverse effects on workability, admixture requirements, and strength properties, leads to significant enhancements in alkali-silica reaction resistance. This, in turn, bestows substantive benefits upon the overarching goal of sustainability enhancement within the construction industry.