Enhancing Sustainability in Concrete: Evaluating the Effects of Rubber Particle Replacement on Workability and Mechanical Properties

This research aims to study the experimental behavior of the addition of rubber particles obtained from waste tires to concrete, as a partial replacement of fine and coarse natural aggregates to various levels. Fine rubber particles (2.5–5 mm) were used as a replacement for fine aggregates, while coarse rubber particles (5–20 mm) were used for coarse aggregates, at levels of replacement of 10%, 20%, 30%, 40% and 50% by volume. This experimental program investigated the fresh properties of rubberized concrete, as well as the mechanical properties (compressive and flexural strengths) of the hardened material.

The results showed that workability increased significantly at replacement of fine rubber type at 30% to 50% and moderately with coarse rubber type replacement at 10% to 30%. Notably, compressive and flexural strengths were reduced at increased replacement levels, with more losses noted for coarse aggregate replacement than for fine aggregate replacement. The mechanical properties were preserved, with the compressive and flexural strengths not significantly affected by the low proportions (up to 10%) of replacement of fine aggregates with fine rubber particles, which is a promising indication that fine rubber could potentially replace fine aggregates.

These results indicate that rubberized concrete, especially at low volumes of fine rubber, seems to be a potential solution for sustainable construction by improving workability and recycling waste tires, as well as having suitable structural performance in some applications. The results of this study warrant the further investigation to optimize the mix designs and develop advanced treatments to improve the bond between rubber particles and the cement matrix.