Eco-friendly concrete with waste ceramic tile as coarse aggregate: mechanical strength, durability, and microstructural properties

The drive towards circular economy in achieving sustainable concrete cannot be overemphasized. The recycling of waste tiles from the ceramic industry, demolished buildings, or during the construction process could be one way of solving the waste generated from ceramic tiles. This study investigates the use of waste ceramic tiles as coarse aggregates in concrete at replacement levels of 0, 10, 20, 30, 50, and 100% by weight of natural coarse aggregate. Concrete cylinders were cast and tested for compressive and splitting tensile strength after a curing period of 7, 14, and 28 days. Further, the durability of the concrete was investigated via water absorption and total permeable pore volumes in all the concrete mixes. The results indicate that the strength of concrete decreases as the percentage of waste ceramic tile aggregate increases. However, adding 10% tile aggregate in concrete seems acceptable as the strength reduction was relatively low. The water absorption and voids increase as waste ceramic tile aggregate increases. Analysis of variance (ANOVA) test was performed to investigate the statistical significance of the waste ceramic tile aggregate on the properties tested. Artificial neural network (ANN) was also performed to predict the compressive strength of ceramic tile concrete. Based on the outcomes, it is recommended to use 10–20% of waste tile aggregate in concrete production where design compressive strength is less than 20 MPa, which can also reduce the demand for new aggregate, reduce the cost of the project, save the dumping issue, and protect the environment.