The moisture induced damage is considered a serious threat to the durability of the high-speed railway system. In this paper, an innovative application of thermoplastic polyurethane/waste rubber powder blend (TPU/WRP) with higher elastic modulus was introduced to enhance the water resistance of high-speed railway structure as a waterproof seal layer. The thermoplastic polyurethane has been proved to have excellent mechanical and waterproof properties, and waste rubber has the advantages in cost and sustainability. The objective of this study was to design the TPU/WRP material and evaluate its moisture resistance and mechanical properties. The compressive test was used to determine the elastic modulus and the permeability test was conducted to verify waterproof performance. Further, the finite element method (FEM) was applied to analyze its mechanical responses under both dynamic and static conditions. The results indicated that TPU/WRP containing 69.2% PU matrix, 30% WRP, and 0.8% PU defoaming agent had excellent supporting and waterproofing properties. Thus, it is recommended to consider TPU/WRP material as a functional waterproof material for preventing subbase and subgrade layers from moisture damage in heavy load traffic environment such as high-speed railway.

湿气引起的损坏被认为是对高速铁路系统耐久性的严重威胁。本文介绍了具有较高弹性模量的热塑性聚氨酯/废橡胶粉末共混物（TPU / WRP）的创新应用，以提高作为防水密封层的高速铁路结构的耐水性。事实证明，热塑性聚氨酯具有出色的机械和防水性能，废橡胶在成本和可持续性方面具有优势。这项研究的目的是设计TPU / WRP材料并评估其耐湿性和机械性能。使用压缩测试确定弹性模量，并进行渗透性测试以验证防水性能。进一步，有限元方法（FEM）被用来分析其在动态和静态条件下的机械响应。结果表明，含有69.2％PU基质，30％WRP和0.8％PU消泡剂的TPU / WRP具有优异的支撑和防水性能。因此，建议考虑将TPU / WRP材料用作功能性防水材料，以防止在高速铁路等重载交通环境中路基和路基层受潮。