Failure mechanism and splitting bond strength of deformed bars considering the effect of loading rate

The bond strength between concrete and steel bar is crucial for simulating the capacity of concrete structures under dynamic loading. This paper aims to gain a better understanding of the local bond deterioration of deformed bars during the pullout process at varying loading rates. The specimens with openings were employed to observe the deformation and propagation of cracks around the interface between concrete and steel bars using digital image correlation technology, and the effects of steel bars diameter and loading rate on bond deterioration were investigated. Based on the partially cracked solution of a thick-walled cylinder under radial internal pressure, the splitting bond strength of deformed bars exposed to different loading rates was investigated. The influence of loading rate on both the strength of concrete and crack development was considered. Finally, the bond strength model was validated against experimental results with good accuracy.