Effects of Loading Rate on Reinforced Concrete Beams

The effects of loading rate on the reinforced concrete beams are experimentally studied in the present paper. Firstly, the effects of strain rate on the different grades of concrete are investigated using the electro-hydraulic servo-controlled testing system at the strain rate that might be experienced during earthquakes. Based on the test results, the dynamic increasing factors (DIF) of concrete are gotten. Then, the dynamic properties of reinforced concrete beams are studied considering different parameters, including concrete strength (C30 and C50), steel strength (HRB335 and HRB400), shear span ratio(λ=5.5 and λ=3.0), loading rate(0.05mm/s and 30mm/s) and loading mode(monotonic loading and cyclic loading). The effects of loading rate on the bearing capacity, ductility, stiffness, failure mode, and energy absorbing of beams are analyzed. Some conclusions with engineering significance are obtained in terms of experimental results.