OPTIMIZATION OF THE COMPRESSIVE STRENGTH OF CONCRETE WITH WASTE CERAMIC TILES AS PARTIAL AGGREGATES USING RESPONSE SURFACE METHODOLOGY

As the construction industry continues to develop, the growing problem of solid building waste disposal remains unresolved. Recent studies showed that ceramic tiles possess similar properties to conventional concrete aggregates. In this study, waste ceramic tiles were incorporated as partial coarse and fine aggregates of concrete, with 25%, 50%, and 75% replacements. Using these percentage replacements, a total of 16 mixes were prepared, and the concrete specimens were subjected to compressive strength test. Strength development was also investigated through testing the specimens at 7, 14, and 28 days of curing period. Based on the experimental results, the compressive strength increased when either fine or coarse aggregates are replaced. When both fine and coarse aggregates are replaced at the same time, the compressive strength generally decreased. In particular, the concrete mix with 75% fine and 75% coarse ceramic aggregates had the lowest nominal compressive strength with 5.72 MPa. Furthermore, Response Surface Methodology (RSM) was used to determine the optimum combination of fine and coarse ceramic tiles. Results showed that the optimum amount of waste ceramic fine and coarse aggregates is 75% and 0%, respectively, yielding 39.37 MPa nominal compressive strength. This is about 39.12% higher than the strength of the control mix, indicating that waste ceramic tiles can potentially replace the conventional concrete aggregates.