A new method for increasing the interface resistance between geopolymer coating and concrete lining structure without applying the organic binder was suggested in this study. Parallel grooves with different depths and orientations were milled on the top surface of concrete block, and well-blended geopolymer mixture (Na-PSS type geopolymer: Sodium poly-sialate-siloxo) was coated upon the grooved interface. The wedge splitting (WS) experiments were conducted to compare the interface adhesion capacity of specimens with different groove width/depth ratios and groove orientations. The average energy release rate (ERR) was calculated by integrating the P_v-CMOD diagram to quantify the interfacial fracture toughness. To understand the interface strength mechanisms and the fracture mode at the front crack mouth, franc 3D simulation was carried out to segregate the mixed fracture mode to determine the initial pure stress intensity factors at the crack mouth. Both the experiments and simulation results indicated that the highest interface fracture toughness was reached by the double diagonal parallel grooves with 0.375 width/depth ratio. These findings put forward a promising attaching method for efficient and reliable passive fire protection coating, with the aim of decreasing the risk of layer delamination in highway tunnels.

中文翻译：

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楔形劈裂法模拟和表征混凝土衬砌结构与地质聚合物平行沟槽界面的黏着力

在这项研究中，提出了一种无需使用有机粘结剂即可增加地聚合物涂层与混凝土衬砌结构之间的界面电阻的新方法。在混凝土砌块的顶面上铣切出具有不同深度和方向的平行凹槽，然后在凹槽界面上涂覆均匀混合的地质聚合物混合物（Na-PSS型地质聚合物：聚唾液酸钠-硅氧烷）。进行楔形劈裂（WS）实验以比较具有不同凹槽宽度/深度比和凹槽方向的试样的界面粘附能力。平均能量释放率（ERR）通过对P _v积分来计算-CMOD图定量界面断裂韧性。为了了解前裂纹口处的界面强度机制和断裂模式，进行了franc 3D模拟以分离混合断裂模式，以确定初始的纯应力强度因子。在裂口处。实验和仿真结果均表明，具有0.375宽/深比的双对角平行沟槽达到了最高的界面断裂韧性。这些发现为有效和可靠的被动防火涂料的附着方法提出了一个有希望的方法，目的是减少高速公路隧道中层脱层的风险。