Optimum Mix for Pervious Geopolymer Concrete (GEOCRETE) Based on Water Permeability and Compressive Strength

¹ Jamilus Research Centre, Universiti Tun Hussein Onn Malaysia, 86400, Batu Pahat, Johor, Malaysia
² Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, 86400, Batu Pahat, Johor, Malaysia
³ Faculty of Civil and Environmental Engineering, International Institute of Cambodia, Sangkat Chak Angre Krom, Khan Mean Chey, Phnom Penh, Cambodia

^* Corresponding author: zurisman@uthm.edu.my

Abstract

The production of ordinary Portland cement (OPC) consumes considerable natural resources and energy, and it also affects the emission of a significant quantity of CO₂ in the atmosphere. This pervious geopolymer concrete study aims to explore an alternative binder without OPC. Pervious geopolymer concretes were prepared from fly ash (FA), sodium silicate (NaSiO₃), sodium hydroxide (NaOH) solution, and coarse aggregate (CA). The effects of pervious geopolymer concrete parameters that affect water permeability and compressive strength are evaluated. The FA to CA ratios of 1:6, 1:7,1:8, and 1:9 by weight, CA sizes of 5–10, 10–14, and 14–20 mm, constant NaSiO₃/NaOH ratio of 2.5, alkaline liquid to fly ash (AL/FA) ratios of 0.4, 0.5, and 0.6, and NaOH concentrations of 8, 10, and 12 M were the pervious geopolymer concrete mix proportions. The curing temperature of 80 °C for 24 h was used. The results showed that a pervious geopolymer concrete with CA of 10 mm achieved water permeability of 2.3 cm/s and compressive strength of 20 MPa with AL/FA ratio of 0.5, NaOH concentration of 10 M, and FA:CA of 1:7. GEOCRETE is indicated to have better engineering properties than does pervious concrete that is made of ordinary Portland cement.