【摘要】 超高性能混凝土(UHPC)由于其优异的力学性能和超强的耐久性,非常适用于损伤普通混凝土(NC)结构的修复加固。UHPC-NC界面的抗剪性能是保证UHPC修复NC结构获得良好力学和抗渗性能的重要因素。通过7组抗剪推出试验,评估了NC界面光滑、凿毛、露筋、刻槽、钻孔和植筋等不同界面处理的UHPC-NC界面抗剪性能和破坏模式。试验结果表明,UHPC-NC界面具有良好的抗剪粘结性能,界面抗剪强度随着NC界面粗糙度的增加而增大,NC界面采用凿毛或刻槽处理的UHPC-NC界面获得了最佳的抗剪承载力,界面破坏方式基本为NC剪切破坏或界面+NC破坏两种模式,未出现完全的界面剥离破坏;光滑和凿毛界面的抗剪破坏为脆性破坏;露筋和钻孔界面的抗剪破坏介于延性破坏和脆性破坏之间,植筋和刻槽界面的延性较好。更多还原

【Abstract】 Ultra-high performance concrete(UHPC) is very suitable for the repair and reinforcement of damaged normal concrete(NC) structures due to its excellent mechanical properties and superior durability. The shear resistance of UHPC-NC interface is important factor to enhance the mechanical properties and the impermeability of concrete structures repaired by UHPC. Seven sets of shear push-out tests were conducted to evaluate the shear resistance and failure models of different UHPC-NC interface treatments, including smooth, chiseling, rebar exposing, grooving, drilling, and rebar bonding. The experimental results show that the interface between UHPC-NC interface has good shear bonding properties, and its shear strength increases with the increase in roughness of NC surface. The UHPC-NC interfaces with the treatments of roughness or grooving on NC surface obtains the best shear resistance, and their failure modes are basically NC shear failure and interface + NC failure modes, and the complete interface peeling failure are not observed. The shear failures of the interfaces with treatments of smooth or chiseling are brittle shear failures. The shear failures of the interfaces with rebar exposing or drilling are between ductile failure and brittle failure, and the rebar bonding or grooving displays good ductility.更多还原