EFFECT OF SHREDDED RUBBER TIRE AS PARTIAL REPLACEMENT FOR COARSE AGGREGATES IN FLY ASH-BASED PERVIOUS CONCRETE

Abstract

The need to improve traditional concrete practices and the existing waste problem in the Philippines has opened an opportunity for by-products, such as scrap rubber tires and fly ash, as sustainable alternative materials in pervious concrete. This study investigates the effect of shredded rubber tires and fly ash content on the strength and permeability of pervious concrete. A total of 15 mix designs, with varying replacement ratios based on weight, were produced and tested for compressive strength, split tensile strength, and infiltration rate. In particular, the percentage replacements tested in the study were 0%, 10%, 20%, 30%, and 40% for the shredded rubber tires, while fly ash ratios were set at 0%, 10%, and 20%. Two-way ANOVA test and desirability function statistical analyses were conducted to determine the optimal replacement of shredded rubber tires and fly ash. Results showed that the addition of shredded rubber tires produced a decreasing trend, while increasing the fly ash content exhibited an increasing trend, both on the compressive strength and split tensile strengths. On the other hand, the infiltration rate increased with the addition of rubber aggregates. The research findings also indicated that using up to 10% shredded rubber tires, with 10–20% fly ash, yields a more desirable pervious concrete than the conventional mix.