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

Abstract

• The study identified that a Na₂SiO₃ to NaOH ratio of 2.5 produced the highest compressive strength, making it the optimal mix for geopolymer concrete (GPC) formulation. • Incorporating nano titanium dioxide (nano-TiO₂) at varying dosages (1% to 5% by weight of GGBS) demonstrated significant influence on the mechanical and durability performance of GPC. • The inclusion of nano-TiO₂ improved key engineering properties such as compressive strength, durability against chemical attacks, and microstructural integrity under ambient curing conditions. • This research reinforces the potential of GGBS-based GPC, enhanced with nano-TiO₂, as a sustainable and high-performance alternative to traditional Portland cement in harsh environmental conditions. 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 (10M) 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.