Investigation on uniaxial dynamic tensile behavior of textile-reinforced ultra-high ductility concrete

Textile-reinforced ultra-high ductility concrete (TR-UHDC) is a new type of cement-based composite material with high tensile strength, tensile strain-hardening and multi-cracking properties. To study the dynamic tensile mechanical properties of TR-UHDC under dynamic load, 38 sets of uniaxial tensile specimens were designed to investigate the effects of dynamic strain rate, polyethylene (PE) short fiber volume content, textile reinforcement ratio, matrix types of ultra-high ductility concrete on the cracking mode and tensile stress-strain curves of TR-UHDC. The strain rate sensitivity of TR-UHDC was evaluated based on the characteristic parameters. The results show that: 1) With the increase of short fiber content, the specimens exhibit multi-cracking characteristics and textile fracture. The short PE fiber can still effectively improve the bonding performance between the textile and the matrix under dynamic load; 2) The dynamic impact coefficient of the tensile strength of TR-UHDC can reach a maximum of 1.637. The parameter analysis indicates that TR-UHDC has a significant strain rate effect; 3) The analysis model established based on the strain rate can effectively predict the tensile strength of TR-UHDC under dynamic and static loads. It provides a foundation for the dynamic tensile strength in engineering design and reduces the potential design risks of TR-UHDC in the field of structural seismic reinforcement.