Optimizing sulfate and acid resistance in rubberized engineered cementitious composite with graphene oxide-pretreated crumb rubber: A response surface methodology approach

Crumb rubber (CR) pretreatment methods effectively mitigate mechanical strength loss in cementitious composites. Yet, their impact on composite durability remains underinvestigated. This study examines the effect of CR pretreatment with graphene oxide (GO) on the durability of rubberized engineered cementitious composite (RECC), employing response surface methodology (RSM) for predictive model development and optimization. Water absorption, sulfate and acid resistance, compressive strength, and the porosity using mercury intrusion porosimetry were evaluated across 16 RSM-generated mixes using five GO concentrations (GOC) (0–1 mg/mL) and three pretreated CR (PCR) replacement levels (1–5%) as input variables. Results reveal increased resistance to water absorption, expansion, weight, and strength loss in sulfate and acid media with higher GOC levels across all PCR groups. Developed response predictive models demonstrate high R² values (53–97%). Optimization resulted in 0.73 mg/mL and 2.5% for GOC and PCR, respectively.