Journal of Structural and Earthquake Engineering

Journal of Structural and Earthquake Engineering

The bond behavior between concrete and rebar under monotonic and cyclic loading

Document Type : Original Article

Authors
1 civil Eng. Babol noshirvani uni. of Technology, Babol, Iran
2 Structural eng. Faculty of Civil engineering. Babol noushirvany uni. Of. Tech.
3 Civil Eng., Babol Noshirvani Uni. of Tech., Babol, Iran
Abstract
One of the most critical factors contributing to the strength, stiffness, and ductility of reinforced concrete members, parti cularly under seismic loading, is the bond between concrete and rebar. This research investigates the bond behavior between c oncrete and rebar in modified beam-end specimens under monotonic and cyclic loading. To this end, ten reinforced concrete s pecimens with dimensions of 200×300×500 mm and eccentric rebar were constructed. The main variables in the construction of the specimens included rebar size, confinement level, and bond length. The specimens were subjected to monotonic and cy clic loading using a universal testing machine. Results indicated that bond stress and stiffness increased with increasing rebar size. A 25% increase in bond stress was observed when the bar size increased from 14 mm to 22 mm. Furthermore, consideri ng the inverse relationship between bond stress and bond length, a 15% decrease in bond stress was observed when the bond l ength was reduced from 200 mm to 132 mm. Additionally, under cyclic loading, bond stress and stiffness decreased by up to 30% due to the accumulation of damage in the bond zone. 
Keywords