Influence of nano titanium dioxide on strength and durability of ambient-cured GGBS-based geopolymer concrete

This study investigates the impact of nano titanium dioxide (nano TiO₂) on the mechanical and durability performance of geopolymer concrete (GPC) produced using ground granulated blast furnace slag (GGBS) and ambient curing conditions. Sodium hydroxide (10 M) and sodium silicate were used as alkaline activators at varying ratios to determine the optimal mix design, with the best compressive strength observed at a Na₂SiO₃/NaOH ratio of 2.5. Nano TiO₂ was then incorporated into the GPC in varying dosages from 1 % to 5 % by weight of GGBS. Compressive, flexural, and splitting tensile strength tests were conducted, along with rapid chloride permeability, water absorption, sorptivity, and resistance to sulfate and chloride attacks. Microstructural properties were assessed using SEM, EDS, TGA/DSC, and FTIR analyses. The optimal nano TiO₂ content was found to be 3 %, which led to a 21.5 % improvement in compressive strength and enhanced durability, with lower permeability and porosity compared to the control mix. Beyond 3 %, performance declined due to nanoparticle agglomeration and microcracking. The results demonstrate that nano TiO₂ can significantly enhance the performance of ambient-cured GGBS-based geopolymer concrete when used within optimal limits.