Geopolymer versus cement-based textile-reinforced mortar: Diagonal compression tests on masonry walls representative of infills in RC frames

Cement production industry is responsible for about 5% of the total anthropogenic CO2 emissions. Alternative materials with reduced carbon footprint progressively introduced in the construction industry could be an effective and sustainable solution to mitigate this impact. This paper examines the replacement of standard cement-based binder with geopolymer-based binder in the application where inorganic-based composites are used for strengthening of existing substandard masonry structures. The focus is given to the in-plane behaviour of masonry walls which serve as infills in reinforced concrete buildings. Past earthquakes have revealed the vulnerability of such structures, which is associated to the brittle nature of infill walls and the poor detailing of the RC frame members. The experimental programme consisted of eighteen diagonal compression tests on square 700 x 700 x 65 mm single-leaf masonry wallettes. The investigated parameters included the matrix of the TRM overlays (geopolymer versus cementitious mortar), the type of the textile reinforcement (14 x 18 mm mesh opening glass textile versus 6 x 6 mm mesh opening basalt textile), and the strengthening layout (two TRM layers on one side only versus one TRM layer per side). The experimental results are discussed in terms of the failure mechanisms, in-plane mechanical properties, ductility and are accompanied by analytical estimates of the experimental TRM contribution. The results of this study prove that geopolymer-based systems are suitable for such retrofitting applications leading to similar - if not better - mechanical response compared to the walls retrofitted with ordinary cementitious binder.

Automated summary

The paper examines the replacement of cement-based binder with geopolymer-based binder in the application of strengthening substandard masonry structures. The focus is on the in-plane behavior of masonry walls in reinforced concrete buildings. The experimental results show that geopolymer-based systems can be suitable for retrofitting applications, with similar or better mechanical response compared to ordinary cementitious binder.