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

Camille A. Issa1, *, Georgio Hilal1
1 Department of Civil Engineering, Lebanese American University, Beirut, Lebanon

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 726
Abstract HTML Views: 379
PDF Downloads: 312
ePub Downloads: 227
Total Views/Downloads: 1644
Unique Statistics:

Full-Text HTML Views: 448
Abstract HTML Views: 247
PDF Downloads: 239
ePub Downloads: 174
Total Views/Downloads: 1108

Creative Commons License
© 2023 Issa and Hilal

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Civil Engineering, Lebanese American University, Beirut, Lebanon; E-mail:



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.

Keywords: Compressive strength, Mechanical behavior, Recycled aggregates, Recycled aggregate concrete, Construction and demolition wastes, Mechanical performance.