Research on Mechanical Properties of Axial-Compressive Concrete Columns Strengthened with TRC under a Conventional and Chloride Wet-Dry Cycle Environment

Abstract

Textile-reinforced concrete (TRC) is currently being used as an effective inorganic reinforcement material due to its high bearing capacity, anticracking capacity, and corrosion resistance. However, the compressive performance of TRC-strengthened concrete columns under chloride corrosion is unclear. Therefore, this paper first studied mechanical properties of RC columns strengthened with TRC with a variable number of textile layers and overlap lengths in a conventional environment. Then, compressive performances of RC columns strengthened with TRC under chloride wet-dry cycling and coupling effects of chloride wet-dry cycling and sustained axial compressive load were studied. The experimental results indicated that the TRC’s constraint ability could make better use of the compressive performance of concrete and improve the failure mode of the compression column. The bearing capacity and ductility of RC columns was improved with an increasing number of textile layers; the increase in the lap length of the textile had only a slight impact on bearing capacities of columns, which slightly improved the ductility of the TRC-strengthened RC columns. The bonding properties of the interface between the TRC and concrete decreased slightly due to the corrosion effect of chloride ions. Thus, the ultimate bearing capacity and deformation capacity of RC columns strengthened with TRC declined after chloride wet-dry cycling; the coupling effects of chloride wet-dry cycles and the sustained axial compressive load negatively affected the bearing capacity and ductility of TRC-strengthened RC columns. The ultimate load and ductility of strengthened columns decreased with the increase in the sustained load.