Preliminary Analysis of the Use of Construction Waste to Replace Conventional Aggregates in Concrete

Abstract

This work aims to study the influence of using construction and demolition waste in the replacement of coarse and fine aggregate to produce recycled aggregate concrete (RAC). A moderate compressive strength concrete made with usual fine and coarse aggregate was used as a benchmark material. Compressive and split tensile tests were performed using 120 cylindrical concrete specimens with 150 mm diameter and 300 mm length. Four-point flexural tests in reinforced beams made with conventional concrete and RAC were performed. The results obtained showed that the use of recycled fine aggregates, in both percentages of substitution investigated—50% and 100%— did not generate any deleterious influence on the values of compressive strength and split tensile strength of the RACs produced. Tin fact, the mechanical strengths of RACs produced with recycled fine aggregate were equal or higher than those from the reference concrete. The same behavior was not observed, however, when the recycled coarse aggregate was used. For this case, decreases in concrete mechanical strengths were observed, especially in compressive strength, with values around 35% lower when compared to the reference concrete. Tensile mechanical tests results confirmed the excellent behavior of all RACs made with replacement of usual fine aggregates by recycled. Bending tests performed in reinforced RAC beams had as objective to evaluate the deformation profile of the beams. The obtained results showed that RAC beams with full replacement of usual fine aggregate by the recycled aggregates have presented little changes in the global behavior, an aspect that encourages its use.

The Use of Crushed Cable Waste as a Substitute of Natural Aggregate in Cement Screed

“…Fine residues containing binding particles often essentially increase the dosage of water and entirely reduce the final mechanical and durability performance of hardened concrete. However, Silva et al (2021) reported exactly the opposite trend, thus utilization of fine RA led to a similar mechanical performance in comparison with the reference mixture; respectively, utilization of coarse RA caused a significant decay [6]. Similar results were reported by Khatib (2005) [7].…”

Effect of Composite Impregnation on Properties of Recycled Coarse Aggregate and Recycled Aggregate Concrete

“…At the same time, in the process of engineering construction, the consumption of natural sand and stone has increased. To protect natural resources and deal with discarded construction waste, the reuse of construction waste has become a key topic in the field of concrete research internationally, which has attracted the attention of experts and scholars from around the world [2]. Recycling construction waste, crushing, cleaning, and screening into a recycled coarse aggregate (RCA) can not only save natural resources and reduce environmental pollution, but also reduce the cost of aggregate used in construction projects.…”

Experimental Study and Theoretical Analysis on the Compression–Shear Multiaxial Mechanical Properties of Recycled Concrete

“…Silva, F.A. et al [ 9 ] used recycled fine aggregates and recycled coarse aggregates to replace ordinary aggregates, considering different replacement rates, and found that the replacement of ordinary coarse aggregates with recycled coarse aggregates had a significant impact on the mechanical properties of concrete, but the replacement of ordinary fine aggregates with recycled fine aggregates had little effect on the overall performance. Lehner, P. and Horňáková, M. [ 10 ] examined the influence of fiber content and pre-compression stress on the chloride ion diffusion coefficient of recycled concrete structures.…”