The risk of cracking/debonding of a cement overlay used to repair or strengthen an existing structure is still a key issue. Current bond test methods are not designed to measure the combined effect of peeling (mode I) and shear (mode

II) on the interface. A few existing models propose theoretical approaches to predict that, but they were fitted on specific cases and lack in generality. In addition, controversial opinions about the influence of both the moisture level of the substrate surface prior to the application of the overlay and properties of the latter on the loading bond capacity call for further investigations. In this work, a cohesive model is developed to predict the loading bond capacity of an existing concrete structure overlaid by a layer of HPFRC/UHPFRC. Different bond tests were specifically designed for calibrating the cohesive parameters employed into the model, which also takes into account the type of the overlay used and the moisture conditioning level. An experimental campaign confirmed the reliability of the predictions of the proposed theoretical model.

用来修复或加固现有结构的水泥覆盖层开裂/脱粘的风险仍然是关键问题。当前的粘结力测试方法并非旨在测量剥离（模式I）和剪切（模式）的综合效果

II）在界面上。现有的一些模型提出了预测这种情况的理论方法，但是它们适用于特定情况且缺乏通用性。另外，关于在施加覆盖物之前衬底表面的水分水平的影响以及衬底的性质对负载粘合能力的影响的有争议的观点需要进一步研究。在这项工作中，开发了一种内聚模型来预测由HPFRC / UHPFRC层覆盖的现有混凝土结构的荷载粘结能力。专为校准模型中使用的内聚参数而专门设计了不同的粘合力测试，该测试还考虑了所用覆盖层的类型和湿度调节水平。一个实验活动证实了所提出的理论模型的预测的可靠性。