Load distribution and passive confinement in reinforced concrete: Development of a mechanical model

Abstract

Understanding the load-bearing behavior of joints between precast concrete elements under compression is of great interest for practical applications, such as tunnel linings. Based on a literature review a research gap on the interaction of a concentrated load introduction (causing geometric confinement) and transverse reinforcement (causing passive confinement) is identified in this paper. This lack of knowledge was addressed in 26 experimental tests at the Institute of Structural Engineering at TU Wien. In these tests the load introduction area, the reinforcement ratio and the load introduction material were varied. Thereby it was confirmed that the confining effect of the transverse reinforcement has a significant influence on the load-bearing behavior. With the experimental results, a new mechanical model including a semi-empirical component for predicting the load-bearing capacity of load transfer zones with geometric and passive confinement was verified and afterwards validated with data from literature. The developed model provides a solution to describe the interaction of geometric and passive confinement based on simple mechanical considerations. In comparison to the existing models implemented in current design codes, where no interaction between geometric and passive confinement is taken into account, a more efficient design for load transfer zones will be enabled.