Application of Talc as an Eco-Friendly Additive to Improve the Structural Behavior of Porous Concrete

Abstract

Talc is an eco-friendly material used in various domains. In this study, talc, quartz and lime sand were added for improving the performance of porous concrete. For this, talc/quartz and lime sand were used as substitute with 5–30% and 5–15% of aggregates, respectively. Compressive strength, porosity and permeability of the porous concrete blocks and their draining capacity were the tested characteristics. Results showed that although by increasing the amount of talc, quartz and lime sand, compressive strength was improved, permeability and porosity were reduced. However, despite the significant difference in hardness of talc and quartz, mixtures containing talc had acceptable performance and were close to quartz so that the average compressive strength of talc samples was only 0.4 MPa less than the quartz ones. It was also found that threshold value for the addition of talc to increase the strength of porous concrete was 25% and over this rate makes no difference in resistance and even reduces it. Results also revealed that all mixtures had good performance in drainage of synthetic urban runoff—the least-permeable talc sample drained 40-mm runoff in 69 s. Also, the most impermeable quartz specimen drained the 40-mm runoff in 44 s. Generally, the mentioned results indicated that talc, as an eco-friendly additive, had acceptable performance in improving the properties of porous concrete.