A Review of Recycled Concrete Aggregates as a Sustainable Construction Material

Abstract

The recent increase in structural developments worldwide, has given rise to the consumption of natural aggregates and energy hence generating a vast amount of construction and demolition waste. Natural aggregates occupy 60-75 percent in volume of the concrete matrix. It is beneficial to recycle construction and demolition waste, for construction activities. One such material retained from construction sites is waste concrete, which can be used to produce recycled concrete aggregates (RCAs). Recycling waste concrete produces a substitute to natural aggregates and preserves the environment by reducing waste disposal at landfills and conserving energy. The use of recycled concrete aggregates has piqued the interest of many researchers by utilization of a full or partial substitution to that of natural aggregates in concrete mixtures. Over the last decade, a significant volume of literature has been published discussing the properties and microstructure of recycled concrete aggregates and its response when used in a new concrete mix. Within this paper a brief history of RCAs is outlined together with statistics on the quantity of concrete waste produced, recycled and its practical applications. A comparison between the RCA and natural aggregate properties are discussed on a microscopic level, such as the density and water absorption capacities. Further to this, a summary of the mechanical and durability parameters are discussed such as compressive, tensile and flexural strengths together with chloride ion penetration. Several pre-treatment methods such as: acid treatment and the use of fine mineral fillers are also discussed. Finally, the conclusions and gaps are stated.

Intermediate Temperature Fracture Resistance of Stone Matrix Asphalt Containing Untreated Recycled Concrete Aggregate

“…Further to this, the largest producer of construction waste in the world, China, produces approximately 2 billion tons of construction waste per year, two million of which is concrete (Gross, 2019). Local studies (Smith et al, 2019;Narcis et al, 2019;Rampit et al, 2020) examined the local construction and demolition waste management industry and concluded that further research would be required into C&D waste management locally. Numerous studies (Moazami et al, 2021;Zhang et al, 2021;Choudhary et al, 2021;Motter et al, 2015;Arabani et al, 2013) have investigated avenues including composite pavement (the combination of flexible asphalt pavements and Portland cement pavements), recycling pavements, and most popularly the substitution of waste materials as aggregate in asphalt mixes.…”

A review on recycled aggregate concretes (RACs)

“…The rapid growth in the urbanization and industrialization has necessitated a demand for concrete usage hence utilizing the maximum amount of natural resources [1]. Among the main constituents of the concrete matrix, aggregates perform a significant role in the concrete matrix due to the large volume occupied, which ranges from 60 -75% of the total volume [2]. Furthermore, coarse aggregates make up a significant portion of this aggregates volume [3].…”