Declining strength is a key limitation for the promotion and application of rubber–cement-based composites. Silane coupling agents (SCAs) provide a new idea for improving the weak interface of rubber–cement-based materials, but the mechanism of SCA modification in the improvement of mechanical properties is not well established. In this paper, for the first time, a multi-scale exploration of SCA-modified rubber–cement-based materials was conducted to explore the modification effect and to reveal the modification mechanism using a combination of experiments and simulations. The experimental results showed that the mechanical properties of KH570-modified rubber–cement-based composites were greatly improved as compared with the composites treated with KH550, KH560, and A151. The modification treatment can effectively introduce KH570 molecules into the weak interface, thus effectively repairing the interfacial defects between the rubber particles and the cementitious material. The molecular dynamics simulation results show that the weak intermolecular interaction between the butadiene group of butadiene rubber and the calcium–silica structure of C–S–H is the essence of the weak combination of the two phases. The mechanical occlusion between KH570 molecules and rubber molecular chains can effectively bond the elastic rubber to the hard cement matrix, improving the frictional resistance and chemical bonding at the interface and giving it full play in the excellent deformation properties of rubber when the composite material is stressed.

中文翻译：

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硅烷偶联剂改性处理改善橡胶-水泥复合材料性能

强度下降是制约橡胶-水泥基复合材料推广应用的关键。硅烷偶联剂 (SCA) 为改善橡胶-水泥基材料的弱界面提供了新思路，但 SCA 改性改善力学性能的机制尚未完全确定。本文首次对SCA改性橡胶-水泥基材料进行了多尺度探索，通过实验和模拟相结合的方式探索改性效果并揭示改性机理。实验结果表明，与用KH550、KH560和A151处理的复合材料相比，KH570改性橡胶-水泥基复合材料的力学性能有很大提高。改性处理可有效地将KH570分子引入弱界面，从而有效修复橡胶颗粒与胶凝材料之间的界面缺陷。分子动力学模拟结果表明，丁二烯橡胶的丁二烯基团与C-S-H的钙-硅结构之间的弱分子间相互作用是两相弱结合的本质。KH570分子与橡胶分子链之间的机械咬合能有效地将弹性橡胶与硬质水泥基体结合，提高界面处的摩擦阻力和化学结合，充分发挥橡胶在复合材料受力时优异的变形性能. 从而有效修复橡胶颗粒与胶凝材料之间的界面缺陷。分子动力学模拟结果表明，丁二烯橡胶的丁二烯基团与C-S-H的钙-硅结构之间的弱分子间相互作用是两相弱结合的本质。KH570分子与橡胶分子链之间的机械咬合能有效地将弹性橡胶与硬质水泥基体结合，提高界面处的摩擦阻力和化学结合，充分发挥橡胶在复合材料受力时优异的变形性能. 从而有效修复橡胶颗粒与胶凝材料之间的界面缺陷。分子动力学模拟结果表明，丁二烯橡胶的丁二烯基团与C-S-H的钙-硅结构之间的弱分子间相互作用是两相弱结合的本质。KH570分子与橡胶分子链之间的机械咬合能有效地将弹性橡胶与硬质水泥基体结合，提高界面处的摩擦阻力和化学结合，充分发挥橡胶在复合材料受力时优异的变形性能. 分子动力学模拟结果表明，丁二烯橡胶的丁二烯基团与C-S-H的钙-硅结构之间的弱分子间相互作用是两相弱结合的本质。KH570分子与橡胶分子链之间的机械咬合能有效地将弹性橡胶与硬质水泥基体结合，提高界面处的摩擦阻力和化学结合，充分发挥橡胶在复合材料受力时优异的变形性能. 分子动力学模拟结果表明，丁二烯橡胶的丁二烯基团与C-S-H的钙-硅结构之间的弱分子间相互作用是两相弱结合的本质。KH570分子与橡胶分子链之间的机械咬合能有效地将弹性橡胶与硬质水泥基体结合，提高界面处的摩擦阻力和化学结合，充分发挥橡胶在复合材料受力时优异的变形性能.