Axial compression behavior of square concrete prisms confined with textile-reinforced ultra-high toughness cementitious composite jackets

Textile-reinforced ultra-high toughness cementitious composite (UHTCC) jackets, referred to as TRU jackets, are a type of high-performance strengthening system. TRU has the excellent tension ductility and crack control capacity of UHTCC, as well as the high tensile strength of textile. In this paper, axial compression tests of TRUconfined square concrete prisms were carried out. The effects of cross-section sizes and textile layer numbers on failure modes and mechanical properties were investigated. The experimental results showed that TRU jacket confinement effectively improved the compressive strength and deformation capacity of concrete. The effect of textile layer numbers was correlated with the sizes of cross-section. With an increase in the cross-section size of specimens, the enhancement of the axial compression performance of confined specimens decreased due to a decrease in the effective confinement stress of jackets. Based on the experimental results, a compressive stressstrain relationship model of TRU-confined concrete is proposed which includes an ascending branch, a plateau branch, and a descending branch. The predicted stress-strain curves are in good agreement with the experimental results, providing an analytical model for the design of TRU-confined concrete structures.