Experimental and numerical investigation of bond performance of RC tension members

Abstract

The bond behaviour between concrete and reinforcement is the root aspect of the reinforced concrete structural performance, both regarding safety and serviceability. To perceive the precise bond behaviour at the concrete-reinforcement interface, a glimpse from the reinforcement core (embedded inside the concrete) is essential. In this article, the bond performance of the deformed bar was investigated both experimentally and numerically. A double pull-out test was performed with tensor strain gauges installed within the modified reinforcement bar. With this reference, two alternative approaches were investigated by finite element (FE) analysis. At first, a plain reinforcement with varied bonding conditions at the specific interval was modelled in three dimensions (Model-1) to simulate the bond behaviour. Secondly, a three-dimensional model with a simplified rib geometry conforming to a predefined bonding index of standard ribbed steel reinforcement was considered as Model 2. Particular focus has been given to rib geometry as one of the dominating factors to comply with FE models. Moreover, each approach’s efficiency is validated with the experimental bond stress along with the bond-slip relation.