Abstract:
The aim of this study is to develop a nano TiO2-modified geopolymer grout and to confirm application in damaged beam-column joints (BCJs). The experimental study was planned in two stages: i) fabrication of an optimal geopolymer grout depending on compressive strength, viscosity, UPV and SEM investigations, ii) injection of the optimal geopolymer grout to damaged BCJ to confirm application. Geopolymer grouts were produced with different NaOH concentrations (8, 10, 12 M) and nano TiO2 contents (5, 10 and 15% of slag weight). The obtained optimal gopolymer grout was injected into the damaged BCJ and subjected to reloading test. Significant improvements in fresh and hardened properties of geopolymer grout samples were provided with modification of NaOH concentrations and nano TiO2 contents. It was also explored that the application of nano TiO2-modified geopolymer grout on the damaged BCJ increased load carrying capacity and ductility in comparison with the reference sample. As a result, a novel eco-friendly geopolymer grout with effective viscosity and high compressive strength was developed and confirmed for utilising in damaged BCJs. © 2021 Elsevier Ltd