Modification of Recycled Concrete Aggregate and Its Use in Concrete: An Overview of Research Progress

Abstract

The differences in physical properties, chemical properties, and mechanical properties between reclaimed concrete aggregate and natural aggregate are discussed in this paper. In this paper, the commonly used improvement techniques of recycled concrete aggregate are reviewed. Physical modification involves peeling the attached mortar layer using mechanical and thermodynamic means, including mechanical grinding and shaping, heat treatment, and microwave or electric pulse treatment. Chemical modification is based on the chemical reaction of some materials with recycled aggregate attached mortar, including acid treatment removal, water glass strengthening, carbonation strengthening, inorganic slurry strengthening, and polymer strengthening. Microbial modification is mainly based on the metabolic activity of specific microorganisms that induce carbon deposition modification. The results show that the reinforced technology of recycled aggregate has made some progress in improving the performance of recycled aggregate, but there are still some problems, such as inconsistent strengthening effects and the unstable compatibility of composite materials. In this paper, future research directions, such as the development of new strengthening materials and the integration of multi-functional strengthening technology, are described in order to provide some theoretical support for the utilization of recycled concrete aggregate.

Enhancing Off-Spec Limestone Aggregates with Polymer Treatment for Sustainable Infrastructure Construction – A Review

“…This technique involves removing small particle size aggregates and fine powder below 4.75 mm by sieving, and it leads to a notable decrease in water absorption and a rise in the average compressive strength of concrete [15].…”

“…Combination with other Technologies: Combining polymer strengthening with other technologies, like microbial-induced carbonization deposition, can enhance the overall strengthening effect of recycled aggregates in a more comprehensive manner [15].…”

“…Chemical Modification: Chemical modification methods involve treating recycled aggregates with specific chemicals or polymers to enhance their properties. Research progress in this area aims to explore the effectiveness of various chemical modification techniques for improving the quality of recycled concrete aggregates [15].…”

Evaluating Recycled Concrete Aggregate and Sand for Sustainable Construction Performance and Environmental Benefits

“…Łukowski et al's 2024 research demonstrates that replacing natural sand with recycled sand in cement mortar offers significant environmental and economic benefits without notably affecting its technical properties, thereby promoting sustainability in construction [18]. Conventional concrete, when utilizing brick or recycled brick aggregates, typically exhibits lower mechanical strength and reduced durability than stone aggregates [19,20]. This is attributed to bricks' higher porosity and decreased strength and density [21,22].…”