Flexural strengthening of RC slabs using textile reinforced mortar improved with short PVA fibers

Abstract

Textile reinforced mortar (TRM) composite is a viable and effective solution for fiber reinforced polymer (FRP) in some limited environments. Short and dispersible polyvinyl alcohol (PVA) fibers were applied in TRM matrix to remedy the lack of cracking strength of TRM composite, which was conducive to improve the cracking capacity and serviceability of flexural members. The effects of the matrix improved with and without short fibers and the reinforcing ratio of textiles on the flexural behavior of reinforced concrete (RC) slabs were studied in this work. Six RC slabs were fabricated and tested under four-point flexural loading, including one control slab, one with one layer of carbon TRM composite without short fibers, one with a matrix improved by short fibers and three with carbon TRM composite improved with short fibers. The results showed that short PVA fibers could increase the cracking capacity of RC slabs by 90 ~ 105%. The flexural capacity of strengthened slabs was increased with the increasing of reinforcing ratio of textiles. Based on the strain compatibility and force equilibrium, an analytical model was given. Moreover, the model was further improved according to the predicted formula of tensile strength for TRM. The theoretical and experimental results showed a very good agreement.