High strength rubberized porous concrete for sustainable pavements: Engineering properties and life cycle assessment

Abstract

This study investigates the performance of Pervious Concrete (PC) with varying quantities of Natural Coarse Aggregate (NCA) replaced by Waste Tire Rubber (WTR) (5%, 10% and 15% by weight) whereas Silica Fume (SF) (5%, 10% and 15%) and Fly Ash (FA) (10% constant) were employed as substitute for cement. This research aims at optimizing the mix of High Strength Rubberized Pervious Concrete (HSRPC) using Supplementary Cementitious Materials (SCMs), comparing experimental stress-strain graphs with the developed constitutive models and conducting a Life Cycle Assessment (LCA). Physical and mechanical performance of PC were examined using permeability and strength indices. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) observed microstructural variations and Interfacial Transition Zone (ITZ) development. The use of WTR increased the permeability and decreased the strength indices. The permeability of mixes with 5, 10 and 15% WTR was found to be 4.00, 4.21 and 4.49 mm/s, which were more than control mix permeability. The compressive strength of PC with 5%, 10%, and 15% WTR was determined to be 32.48, 29.29, and 26.94 MPa, respectively, which were lower than control PC compressive strength which was 35.41 MPa. However, the addition of SF and FA enhanced the mechanical properties while causing a decrease in the permeability. Increasing SF content from 0% to 15% enhanced the compressive strength of PC containing 5% WTR, from 32.48 to 40.71 MPa. Developed constitutive models compared the stress-strain response of PC. Life cycle assessment showed that WTR, SF, and FA-based PC reduced the global warming.