Evaluation of Mechanical and Durability Properties of Concrete with Recycled Materials for its use in Interlocking Concrete Pavement

Abstract

The use of coarse recycled concrete aggregates (CRCA) in concrete as a replacement for natural aggregate (NA) has recently sparked a lot of attention. The use of CRCA is gaining acceptance as more research into its performance is conducted. Similarly, incorporating supplementary cementitious materials (SCMs) into concrete mixes helps to reduce cement consumption and carbon dioxide emissions. The substitution of NA for CRCA and conventional cement for SCMs is a potential step toward more sustainable concrete that conserves natural resources while reducing the environmental impact of concrete. As a result, using these materials is a more eco-friendly option. This study focuses on the mechanical and durability properties of concrete mixes, including CRCA and SCMs, for use in interlocking concrete pavers (ICP). Three concrete mixes with varied ratios of CRCA and SCMs are compared to the performance of the control mix. Ground Glass Puzzolans (GP) and Ground Granulated Blast Furnace Slag were employed as SCMs in this investigation. The fresh properties of the mixes, including slump and air content, were investigated. Compressive strength, shear strength, splitting tensile strength, water absorption, and freeze-thaw resistance are among the hardened characteristics of diverse mixes investigated. The results show that concrete mixtures containing CRCA and SCMs performed similarly to the NA and general use limestone cement (GUL) control mix (CM) in terms of compressive strength and even outperformed the CM in terms of water absorption and freeze-thaw durability. A general trend of decreasing compressive strength with increasing percentage replacement of CRCA was observed; however, compressive strength was seen to improve with the addition of SCMs. The increase in the quantity of CRCA in concrete mixtures led to a decrease in the values of shear strength and splitting tensile strength and the addition of SCMs did not significantly contribute to these values. The water absorption value is observed to increase in the mixture containing only partially replaced CRCA, but it is observed to be better in the mixture containing CRCA and SCM. Compared to the CM and mix with only CRCA, the freeze-thaw durability measured in terms of mass loss was better for mixes with CRCA and SCMs. The findings of this study provide strong evidence to encourage the use of CRCA and SCMs to partially replace NA and conventional cement and serve as a step toward more sustainable concrete.