Mechanical behavior of concrete beams shear strengthened with textile reinforced geopolymer mortar

This paper presents results from static load tests on ten RC beams, including eight shear strengthened beams with textile reinforced geopolymer mortar (TRGM), one shear strengthened beam with textile and epoxy resin, and one un-strengthened beam. The effects of number of textile layers, textile geometry, adhesive type and anchorage measures using steel strips on shear capacity of strengthened beams were investigated. The effective strain of textile in TRGM strengthened beams at failure were compared to that in shear strengthened beams with ordinary textile reinforced mortar (TRM) in previous studies. The data from tests show that the enhancement of shear capacity achieved by one layer and two layers of TRGM strengthening with respect to the un-strengthened beam are 47% and 106% respectively. And the shear capacity can get further enhancement by 15–21% when steel strips anchorage is incorporated. The effective strain developed in textile of TRGM shear strengthened beams is comparable to or even higher than that in TRM strengthened beam with similar wrapping configuration. Although one layer of TRGM is about half as effective as its resin-based counterpart in terms of increasing shear capacity, TRGM is a very promising solution for retrofitting and strengthening RC members, due to its superior fire resistance, excellent corrosion resistance and good weatherability. The calculated shear capacity of TRGM strengthened beams, using the modified model for the effective strain for TRGM, shows a reasonable agreement with the tested results.