以型钢混凝土标准推出试验为基础,分析型钢与混凝土之间的黏结性能与应力传递。在考虑型钢与混凝土之间三维空间黏结作用效果的基础上,建立推出试验的力学桁架模型,该桁架模型可以较好地反映型钢混凝土各种黏结破坏形态的破坏机理。混凝土强度、型钢翼缘的保护层厚度、配箍率、型钢的锚固长度是影响型钢与混凝土之间黏结强度的主要因素,利用桁架模型分析了这些因素对黏结强度的影响,得出以下结论:黏结强度随着混凝土强度的增大而提高;随着型钢翼缘保护层厚度的增加,混凝土保护层所能承担的拉力逐渐增大,极限荷载和黏结强度相应提高;配箍率的增加可以有效提高黏结破坏后的残余黏结力;随着型钢锚固长度的增加,试件能承受的极限荷载增大,型钢与混凝土接触面的黏结强度减小。
Bond performance and stress transfer between steel and concrete were analyzed based on the standard push-out test of steel reinforced concrete specimens.A mechanical truss model,which was put forward based on the three-dimensional bond effect,was established and used to illuminate various bond failure patterns of push-out specimens.Strength of concrete,the depth of the concrete cover of steel flange,the reinforcement ratio,and the anchorage length of shaped steel are the main factors that affect the bond strength between steel and concrete.The mechanical truss model was utilized to analyze the influences of these factors.The results show that the bond strength increases with the strength of concrete;the bond strength and the ultimate load are enhanced with the increase of the depth of the concrete cover of steel flange;the arrangement of more stirrups can improve the residual bond strength after bond cracking,which is mainly due to the restriction of stirrups on cracks;and the ultimate load of specimens increases,while the bond strength decreases,with the increase of the anchorage length of shaped steel.