Sustainable Construction Materials: Recycled Aggregate Concrete from Known Concrete Strength Debris

Landfills receive construction and demolition wastes (CDW) that are the debris generated during the construction, renovation, and demolition of buildings, roads, and bridges. CDW are resources that could be used in new construction projects, thus eliminating the need for virgin materials to be mined and processed.

The main objective of this study is to develop a novel investigation of the mechanical behavior of concrete mix design incorporating recycled aggregate concrete (RAC) from casted concrete debris of known compressive strength while meticulously monitoring the effective water-to-cement ratio.

The following four variables were monitored while performing the concrete mix design: the percentage of recycled coarse aggregates (RCA), the percentage of recycled fine aggregates (RFA), the gradation of the recycled material used, and the original compressive strength of the casted concrete debris. The initial strength and size of the debris versus the quantity of usable recycled materials obtained were investigated. The consequence of the utilization of each variable in the final concrete mix was determined. The mechanical properties investigated were the compressive strength, flexural strength, and modulus of elasticity of concrete made with different percentages of recycled materials.

The result of this study is achieving an optimum concrete mix design that also results in minimizing the negative impact on the environment by reducing the amount of CDW being dumped in landfills.

The combination of both recycled coarse and recycled fine aggregates resulted in an increase in mechanical performance of the concrete while enhancing the environmental value of the final material.