Strengthening of conventional columns through RPC sandwich tube against blast loading

Abstract

This paper investigates the protective effect and design method of reactive powder concrete cored sandwich tube (RPCST) for conventional reinforced concrete (RC) columns. For this purpose, the blast performance of the RPCST and RC members is verified by comparing the numerical results with the blast experiments, respectively. Then, the blast performance of the columns jacketing with RPCST is investigated using numerical simulations. Factors affecting the blast performance of columns strengthened with RPCST jackets are investigated. It is found that the flexural-shear damage of RC column can be further divided into three failure types. Flexural and shear stiffness of conventional column with RPCST retrofitting are significantly improved, and the columns experience shear or flexural-shear damage before strengthening and mainly show flexural damage after enhancement. In view of the brittle failure of some columns with smaller deformation and better bearing capacity, a modified failure index is proposed to judge whether the columns require enhancement. Based on parametric analysis, a mathematical model is proposed to predict the peak deformation of columns strengthened with the RPCST jacket. The deformation prediction model and judgement index of the column can serve as a basis for the anti-explosion design.