Experimental Study on Bending Performance of Ultra-high Strength Reinforced Concrete Beams under Static Loading

11 sets of reinforced concrete beams with different steel bar strength, concrete strength, and reinforcement ratios are designed and manufactured to study the bending performance of ultra-high strength reinforced concrete beam. The failure morphology, bending response, yield load, ultimate bearing capacity, and crack width of specimen are experimentally studied using a four-point static loading method. The results indicate that the maximum bearing capacity of reinforced concrete beam can be improved by strengthening the strength of steel bars, the increase in the strength of concrete has a relatively small impact on the flextural bearing capacity of beam, and the increase in the longitudinal reinforcement ratio can significantly improve the flextural bearing capacity of reinforced concrete beams. The HTRB600 / 700 ultra-high strength reinforced concrete beam is the same as ordinary reinforced concrete beam in terms of stress morphology, bending response, and failure mode. Its yield load and ultimate bearing capacity can still be calculated usung relevant code formulas. For bending beam components, the recommended design value for tensile strength of HTRB600 steel bars is 520 MPa, and the recommended design value for tensile strength of HTRB700 steel bars is 610 MPa; The measured maximum crack width of ultra-high strength reinforced concrete beam specimen under short-term load is greater than the calculated value in relevant specifications. Therefore, the adjustment coefficient k of a maximum crack width is proposed and the calculation formula is modified. After adjustment, the calculated value obtained is in good agreement with the experimentally measured value. © 2023 China Ordnance Industry Corporation. All rights reserved.