Flexural behavior of concrete slabs strengthened with textile reinforced geopolymer mortar

This paper presents results from experimental and numerical studies on the flexural behavior of reinforced concrete (RC) one-way slabs strengthened with textile reinforced geopolymer mortar (TRGM). Eight one-way RC slabs, comprising of five TRGM strengthened slabs, two TRPM (textile reinforced polymer-modified cement mortar) strengthened slabs and one un-strengthened slab, were tested under static loading. The varied parameters in the experiments included the number of textile layers, spacing of the lateral textiles, presence of anchorage, and type of binder. Data from the tests is utilized to validate finite element models developed to simulate the flexural response of TRGM strengthened slabs. Then a set of parametric studies were conducted, to evaluate the effect of reinforcement ratio, slab thickness and the number of strengthening layers. Results from the tests and numerical studies clearly show that use of TRGM for strengthening delays the development and progression of cracks in slabs and enhances the post-cracking stiffness, as well as flexural capacity. In addition, the flexural capacity increases with increased number of strengthening layers, and decreased spacing of lateral textiles. Compared with TRPM strengthened slabs, TRGM strengthened slabs possess higher flexural capacity and better crack control. Finally, a calculation model for predicting the flexural capacity of TRGM strengthened slabs is proposed and the model predictions of flexural capacity is in good agreement with the results from tests and numerical simulations.