A Comprehensive Review on Recycling of Construction Demolition Waste in Concrete

Abstract

There have been efforts to use building demolition waste as an alternative aggregate in concrete to decrease the use of natural resources for construction. The World Green Building Council estimates that the construction industry is responsible for more than 50% of all material extracted globally and that construction and demolition waste makes up 35% of global landfills. As a result, incorporating recycled aggregate (RA) in concrete production is a prudent course of action to reduce the environmental impact. This study reviews prior research on using recycled aggregate instead of conventional ingredients in concrete. The composition and morphology of different types of RA, the behavior of RA in fresh and hardened states, keyword co-occurrence and evolution analysis, and the various additives used to enhance the inferior properties of RA are discussed. The RA showed different physical properties when compared with natural aggregate. However, the addition of pozzolanic materials and various pretreatment techniques is desirable for improving the inferior properties of RA. While building waste has been utilized as a substitute for fine and coarse aggregate, prior research has demonstrated that a modified mixing approach, an adequate mixing proportion, and the optimum replacement of cementitious materials are necessary. Based on the review, the recommendation is to use RA at a replacement level of up to 30% and the addition of precoated and pozzolanic materials as a treatment to provide concrete with adequate workability, strength, and durability for structural applications.

Recycled Sand and Aggregates for Structural Concrete: Toward the Industrial Production of High-Quality Recycled Materials with Low Water Absorption

“…The selective separation hence addresses the need to remove the adhered cement paste from aggregates in an economically feasible way [9,49]. It enables the complete recycling of old concrete back to concrete and cement production and thus significantly contributes to its sustainability [4].…”

“…It enables the complete recycling of old concrete back to concrete and cement production and thus significantly contributes to its sustainability [4]. Already today, the construction industry is responsible for more than 50% of material extracted and for a third of global landfills [9]. Concrete demand is further expected to grow.…”

“…Even the coarse recycled concrete aggregates from the conventional recycling process show a reduction in specific gravity, an increase in porosity, the crushing index, high water absorption, and a weak interfacial transition zone [9] compared to virgin materials. This makes their use in concrete production challenging, requiring higher cement dosages [10] than an equivalent concrete made of natural aggregates.…”

“…Various methods to improve the properties of recycled concrete aggregates were proposed and investigated (see, e.g., [9,12] and references therein), but many fail to provide an economically feasible solution (e.g., thermal treatment or polymer treatment) and/or a clear environmental benefit (e.g., treatment with lime, extra cement or acid treatment). The RCF is hence mainly considered a by-product and is intended for low-grade applications [13].…”

Microstructure and Water Retention Kinetics in Autogenous Cured Self-Compacting Concrete Blends Using Super Absorbent Polymer

“…Additionally, the manufacture of cement results in a rise in the carbon footprint, which is a significant problem that threatens the viability of the ecosystem [ 5 ]. Several options are conceivable to address this issue, including the use of alternative cementitious substances such as fly ash and silica fumes to cut down on the quantity of Portland cement required [ 1 , 5 , 6 , 7 , 8 , 9 , 10 ]. The ability of structures to withstand chemical attacks, weathering, and abrasion resistance of concrete blends is a major problem when these alternative cementitious ingredients are used [ 11 ].…”