纳米粒子和纤维协同改性地聚合物砂浆流变与粘结特性及力学行为

Geopolymer mortar is a kind of environment friendly building material serving as a repair material for concrete structures because it can save energy and resource consumption and reduce environment pollution, which is generated from the cement manufacture. This project will select geopolymer mortar synergistically modified by nano particles and fibers as the study object. The combined method of experiment and theory will be adopted to investigate the rheology properties, interface bonding properties, bending toughness and fracture properties of the geopolymer mortar synergistically modified by nano particles and fibers. Besides, the rheology model reflecting the presure, temperature and time of the geopolymer mortar composite will be established. And then, the loss mechanism of the working performance of the mortar composite during the course of transportation process will be revealed. The constitutive relation model of bonding and slipping between the geopolymer mortar composite and concrete will also be established, and the bonding mechanism of the geopolymer mortar composite will be revealed. Moreover, the fracture damage and bending damage mechanism of the geopolymer mortar containing nano particles and fibers will be clarified. Furthermore, the microstructure of the mortar composite will be studied using the microscopic test method. Finally, the effect mechanism of the synergistic effect of nano particles and fibers on the rheology properties, interface bonding properties and mechanical behavior of the geopolymer mortar will be revealed from the micro level applying the view of energy, combining macroscopic and mesoscopic view, combining damage and fracture view. The expected results of this study has great theoretical significance and practical value to enrich and develop the basic theory of geopolymer composite and has great contribution on the engineering application of the geopolymer mortar synergistically modified by nano particles and fibers.

地聚合物砂浆用作混凝土结构修复加固材料，可节约能源与资源消耗，减轻大量水泥生产带来的环境污染，是一种环境友好型建筑材料。本项目以纳米粒子和纤维协同改性地聚合物砂浆为研究对象，拟采用试验与理论相结合的方法研究其流变特性、界面粘结特性、弯曲韧性及断裂性能，建立考虑压力-温度-时间的地聚合物砂浆流变模型，揭示地聚合物复合砂浆的工作性能损失机理，建立地聚合物复合砂浆-混凝土粘结滑移本构关系模型，揭示地聚合物复合砂浆的粘结机理，阐明掺纳米粒子和纤维地聚合物砂浆断裂损伤及弯曲破坏机理，利用微观测试方法对地聚合物复合砂浆的微观结构进行研究，应用能量观点以及宏观与细观、损伤与断裂相结合等观点，从微观层次上探明纳米粒子与纤维协同作用对地聚合物砂浆流变与粘结特性及力学行为影响的作用机理。本项目预期成果对丰富和发展地聚合物基复合材料基本理论，推动纳米粒子和PVA纤维协同改性地聚合物砂浆的工程应用具有重要意义。

随着地聚合物基砂浆研究的深入以及纳米材料制造成本的降低，纳米粒子和纤维协同改性地聚合物砂浆将会是未来混凝土结构补强加固中应用潜力极大的一种绿色建筑材料。本项目通过地聚合物砂浆的流变性试验，探究了纳米粒子掺量及纤维掺量等砂浆配合比参数对地聚合物砂浆屈服应力、塑性粘度等流变参数的影响规律，分析了各参数等对地聚合物砂浆流变特性的影响机制，建立了地聚合物砂浆流变模型，揭示了地聚合物复合砂浆工作性损失机理；通过地聚合物砂浆剪切粘结试验，测试出掺纳米粒子和纤维改性地聚合物砂浆与混凝土基体间的界面粘结参数，研究了纳米粒子掺量、纤维掺量、混凝土基体强度等级、混凝土基体表面粗糙度对界面粘结强度的影响规律，建立了地聚合物砂浆-混凝土粘结滑移本构关系模型，分析了纳米粒子和纤维协同改性地聚合物砂浆与混凝土基体间的界面粘结机理；通过抗压、抗拉试验及预切口梁式试件的三点弯曲试验，分别测得掺加纳米粒子和纤维地聚合物砂浆试件的基本力学性能参数及断裂参数，分析了纳米粒子及纤维掺量对地聚合物砂浆各力学性能参数及断裂性能参数的影响，分析了地聚合物复合砂浆断裂损伤及破坏机理；利用微观测试方法对掺加纳米粒子和纤维的地聚合物砂浆进行了微观物相分析，研究了纳米粒子和纤维对地聚合物砂浆微观形态及孔结构的影响，对地聚合物砂浆与混凝土基体粘结面及试件破坏断面进行了微观测试分析，从微观层次上探明了纳米粒子与纤维协同作用对地聚合物砂浆流变特性、粘结特性及力学行为影响的作用机理。本项目研究成果将会为纳米粒子和纤维协同改性地聚合物砂浆的推广应用提供可靠的理论依据，具有广阔的应用前景。