Recycling of waste rubber into concrete is one of the most efficacious and environmentally-friendly methods to solve the so-called black pollution. However, the incorporation of waste rubber particles reduces the mechanical properties of concrete, resulting from the low stiffness of the rubber particles as well as the insufficient adhesion energy between waste rubber and hardened cement paste. To solve the latter issue, an innovative surface treatment method for hydrophilicity improvement of waste rubber using polyvinyl alcohol (PVA) is proposed in this paper. The interfacial strengthening mechanism of waste rubber/cement paste using PVA is systematically studied from the aspects of macro-scopic mechanical properties, micro-structure characteristics and molecular-scale modifications. The addition of 0.1% PVA solution can significantly enhance the compressive and flexural strength of rubber-cement composites by 7–14% and 20–38% at the age of 28 days, respectively. SEM observation and EDS results verify the bridging effect of PVA at the waste rubber/cement paste interface, which eliminates the gap caused by the hydrophobicity of rubber. The molecular dynamics simulation shows that the interfacial adhesion energy between rubber hydrocarbon (RH) and PVA is 52% higher than that between RH and calcium-silicate-hydrate (C–S–H), resulting in the accumulation of PVA molecules on rubber surface by van der Waals force and electrostatic interaction. The RH/PVA/C–S–H model has better mechanical properties than the RH/C–S–H model, verifying the bridging role of PVA at the molecular scale.

将废旧橡胶回收到混凝土中是解决所谓的黑色污染最有效，最环保的方法之一。但是，废橡胶颗粒的掺入降低了混凝土的机械性能，这是由于橡胶颗粒的硬度低以及废橡胶与硬化的水泥糊之间的粘合力不足所致。为解决后一个问题，本文提出了一种创新的表面处理方法，以利用聚乙烯醇（PVA）改善废橡胶的亲水性。从宏观力学性能，微观结构特征和分子尺度的变化等方面，系统地研究了使用PVA的废橡胶/水泥浆界面增强机理。0的加法。1％的PVA溶液可在28天时显着提高橡胶水泥复合材料的抗压强度和抗折强度，分别提高7-14％和20-38％。SEM观察和EDS结果证明了PVA在废橡胶/水泥浆界面处的桥接效果，消除了橡胶疏水性造成的间隙。分子动力学模拟表明，橡胶烃（RH）与PVA之间的界面粘附能比RH与硅酸钙水合物（C–S–H）之间的界面粘附能高52％，从而导致PVA分子在橡胶表面积累通过范德华力与静电相互作用。RH / PVA / C–S–H模型具有比RH / C–S–H模型更好的机械性能，从而验证了PVA在分子尺度上的桥接作用。