钢绞线网增强ECC与混凝土刻槽式界面粘结性能试验

Experimental on bond properties of grooved interface between high-strength steel wire mesh reinforced ECC and concrete

  • 摘要: 为研究刻槽构造对钢绞线网增强工程用水泥基复合材料(High strength steel wire mesh reinforced engineered cementitious composites,HSSWM-ECC)与混凝土界面粘结性能的影响,考虑刻槽数量、刻槽深度、钢绞线直径、纵向钢绞线配筋率及ECC抗拉强度等因素,对设计制作的12组36个梁铰式试件进行了界面粘结性能试验。结果表明:HSSWM-ECC与混凝土界面粘结破坏形态有界面剥离破坏和钢绞线断裂破坏两种;在刻槽参与受力总宽度20 mm及槽深5 mm范围内,增加刻槽数量和刻槽深度均能有效提高界面粘结性能;而纵向钢绞线配筋率和ECC抗拉强度与界面粘结性能指标(粘结应力及对应滑移量)呈线性相关性。基于刻槽界面粘结机制分析,建立了考虑界面键槽特征(刻槽数量、槽深)及HSSWM-ECC层强度特征(钢绞线配筋率、钢绞线直径、ECC抗拉强度等)的刻槽处理界面抗剪承载力预测模型。经验证分析,该界面受剪承载力计算模型与试验结果吻合良好。

     

    Abstract: In order to study the effect of grooved interface on the bonding properties of high-strength steel wire mesh reinforced engineered cementitious composites (HSSWM-ECC) and concrete, a total of 36 specimens in 12 sets were designed and fabricated for beam tests, considering the effect of the number of grooves, depth of grooves, steel strand diameter, longitudinal strand ratio and tensile strength of ECC. The results show that the damage patterns include interfacial peeling failure and strand fracture damage. Within the range of the total grooves involved width of 20 mm and the groove depth of 5 mm, the bond behavior between HSSWM-ECC and concrete can be effectively improved by increasing the number or depth of grooves. The longitudinal strand ratio and ECC tensile strength are linearly correlated with the interface bond performance indicators (bond stress and its corresponding slip). Based on the analysis of the bonding mechanism of the grooved interface, a prediction model of the shear bearing capacity considering the groove features (number of grooves, depth of grooves) and the strength characteristics of the HSSWM-ECC layer (longitudinal strand ratio, strand diameter, ECC tensile strength) is established, which is in good agreement with the test results.

     

/

返回文章
返回