超高性能混凝土预制节段梁接缝抗剪性能尺寸效应试验

Study on Dimensional Effect of Joint Shear Resistance of Ultra-High Performance Concrete Precast Segmental Beams

UHPC是一种特殊的混凝土材料,具备卓越的力学性能和耐久性。装配化建造方式中的节段预制和拼装梁技术为UHPC的应用开辟了新的可能性。然而,接缝处对抗剪承载力有着较大的影响。为了研究键齿尺寸对接缝界面的抗剪性能的影响,通过进行12组UHPC接缝键齿尺寸效应直剪试验,分析了不同键齿高度(15、30、45、60 mm)以及不同钢纤维掺量(1%、2%和3%)对承载性能的影响。结果发现:随着试件键齿尺寸的增加,接缝处的剪应力呈下降趋势;接缝处的键齿高度对抗剪承载力有明显的尺寸效应;随着钢纤维掺量的增加,接缝处的键齿对抗剪承载力的尺寸效应逐渐增强。

UHPC is a special concrete material with excellent mechanical properties and durability.The segmental prefabrication and assembled beam technology in the assembly construction mode opens up new possibilities for the application of UHPC.However,the joint has great influence on the shear resistance.In order to study the effect of key tooth size on the shear properties of joint interface,12 sets of direct shear tests of joint key tooth size effect were carried out to analyze the effects of different key tooth height(15mm,30mm,45mm and 60mm)and different steel fiber content(1%,2%and 3%)on the bearing properties.It is found that the shear stress at the joint decreases with the increase of the key tooth size.The height of the key teeth at the joint has obvious dimensional effect on shear resistance.With the increase of steel fiber content,the size effect of the key teeth at the joint against shear strength is gradually enhanced.