Flexural performance of precast hollow-core slabs strengthened with textile-reinforced highly ductile concrete (TRHDC)

Textile-reinforced highly ductile concrete (TRHDC) was a promising composite material, which exhibited multiple crack characteristics, high cracking and ultimate tensile strength under uniaxial tension. In this study, six precast hollow-core slabs including one reference slab and five TRHDC-strengthened slabs were manufactured and tested as simply supported under four-point bending. The parameters under investigation included: (i) the TRHDC matrix added with or without polyvinyl alcohol (PVA) fibers, and (ii) the number of textile layers. The test results indicated that adding PVA fibers in the TRHDC matrix could effectively limit the crack width of TRHDC composites, and multi-crack behavior was observed in the strengthening overlay. Besides, TRHDC composites were efficient in enhancing the flexural capacity of strengthened slabs, which were 70–113% in cracking load, and 74–132% in peak load compared with the reference slab. Finally, based on the plane section assumption, an analytical model was given to predict the flexural capacity of TRHDC-strengthened slabs.