CFRP-钢复合筋珊瑚海砂海水混凝土梁受剪性能试验及承载力计算OA北大核心

In order to reveal the shear failure mechanism of CFRP-steel composite bars reinforced(C-FSCB)coral sea-sand seawater concrete(CSSC)beams,17 beam specimens were designed and fabricated for shear performance tests,including 15 C-FSCB reinforced CSSC beams and two CSSC beams reinforced with steel bars.The main variables included shear-span ratio,stirrup spacing,longitudinal reinforcement ratio,reinforcement material type,and concrete strength.The crack development,failure process,and failure modes of the beam specimens were observed during the experiments,and shear-deflection curves and strain distribution data were obtained.Test results show that increasing the reinforcement ratio and stirrup ratio causes the failure mode of the C-FSCB reinforced CSSC beams to change from shear failure to bending failure.For beams with different types of reinforcement,the bending-shear failure modes exhibit consistent trends as the variation of shear-span ratio.Compared with the reinforced CSSC beams,the peak shear force of the C-FSCB reinforced CSSC beams increases by 16％,while the ductility decreases by 23％.With the increases of reinforcement ratio and stirrup ratio,the peak shear force of the beams gradually increases.Increasing the stirrup ratio enhances the ductility of the beams,while increasing the reinforcement ratio has the opposite effect.Although increasing the shear-span ratio leads to a reduction in the peak shear force,the ductility gradually improves.The analysis of the strain data reveals that,unlike the reinforced CSSC beams,the shear force of the C-FSCB reinforced CSSC beams continues to increase after the yielding of stirrups.Additionally,with the increases of reinforcement ratio and stirrup ratio,the stirrup strain corresponding to the peak shear force of C-FSCB reinforced CSSC beams decreases.Based on the lower bound value principle of the statistical results from the experimental data,a design calculation formula for the shear capacity of C-FSCB reinforced CSSC beams was established.The experimental results are all greater than the calculated results,indicating a conservative approach to safety.