Ultra-high performance concrete (UHPC) shows very different properties such as high level of autogenous shrinkage and low creep coefficient compared to conventional concrete. One of the problems posed by this is that when UHPC is used as a thin, bonded overlay for concrete bridge decks or pavements, there is limited information regarding the shrinkage-induced warping of the overlay and optimization designs to minimize it. This study conducted a hygro-mechanical finite element analysis to investigate the warping behavior of UHPC overlay cast on mature substrate of normal strength concrete (NSC). The simulation results were validated with the observations from outdoor overlay tests. It is shown that incorporating the shrinkage and creep of UHPC and the bonding behavior of the overlay-to-substrate interface can predict the UHPC overlay's warping deformation in an accurate way. Based on the model, a parametric study was carried out to investigate the influences of sealed curing period, the roughness degree (the bond strength) of overlay/substrate interface, the overlay thickness, the rebar reinforcement inside the overlay, and the amount of total (free) shrinkage of UHPC on the magnitude of the overlay's warping. The findings obtained in this study include the following: (1) The UHPC's shrinkage and the bond strength between UHPC overlay and substrate are two essential factors affecting the overlay's warping behavior, (2) With an increase in UHPC overlay thickness, the calculated overlay's warping deformation is slightly increased, and (3) Internal rebar reinforcement has a limited contribution to reduce the overlay's warping.

与传统混凝土相比，超高性能混凝土 (UHPC) 具有非常不同的特性，例如高水平的自收缩和低蠕变系数。这带来的问题之一是，当 UHPC 用作混凝土桥面的薄粘合覆盖层时或路面，关于覆盖层的收缩引起的翘曲和优化设计以使其最小化的信息有限。本研究进行了湿力学有限元分析，以研究 UHPC 覆盖浇注在正常强度混凝土 (NSC) 成熟基材上的翘曲行为。模拟结果通过室外覆盖测试的观察结果得到验证。结果表明，结合UHPC的收缩和蠕变以及覆盖层与基板界面的粘合行为可以准确预测UHPC覆盖层的翘曲变形。基于模型，参数化研究研究了密封固化时间、覆盖层/基材界面的粗糙度（粘合强度）、覆盖层厚度、覆盖层内钢筋以及 UHPC 的总（自由）收缩量对覆盖层翘曲的幅度。本研究获得的结果包括：（1）UHPC 的收缩率和 UHPC 覆盖层与基材之间的粘合强度是影响覆盖层翘曲行为的两个重要因素，（2）随着 UHPC 覆盖层厚度的增加，计算的覆盖层翘曲变形略有增加，并且 (3) 内部钢筋对减少覆盖层翘曲的贡献有限。