配置全HRB600钢筋的混凝土梁受弯性能试验研究OA

To investigate the applicability of HRB600 high-strength steel bars in symmetrically reinforced concrete beams,this paper systematically analyzed the influences of longitudinal reinforcement ratio and longitudinal reinforcement strength on beam flexural capacity,deformation capacity,flexural stiffness and crack width through static flexural tests of five reinforced concrete beam specimens and finite element numerical simulations.The results show that beams with symmetrically configured HRB600 high-strength steel bars as longitudinal reinforcement exhibit the ductile failure characteristics typical of under-reinforced beams,and their mechanical behavior is consistent with that of ordinary reinforced concrete beams.Increasing the longitudinal reinforcement ratio improves the flexural and deformation capacities of beams.When the longitudinal reinforcement ratio reaches 1.53％,the increments in flexural capacity and deformation capacity of the beam become limited.When ordinary longitudinal bars are replaced with HRB600 bars via equivalent strength substitution,the flexural deformation capacity of beams increases,and longitudinal reinforcement consumption is reduced by 16％～30％.The formulas for calculating flexural capacity and crack width specified in current design codes are applicable to reinforced concrete beams with HRB600 high-strength bars.The code-calculated short-term stiffness values of flexural beams are overestimated,while the proposed modified formula can effectively reflect test results and is convenient for design use.Higher concrete strength can improve the flexural capacity of beams,and concrete with strength grade of C40 or higher can achieve good composite action with HRB600 steel bars.To improve the ductility of flexural beams,compressive longitudinal reinforcement needs to be arranged at the top.