聚合物-沥青-水泥复合胶凝体系的凝结硬化机理及微观结构的研究

项目名称： 聚合物-沥青-水泥复合胶凝体系的凝结硬化机理及微观结构的研究

项目编号： No.50802050

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 孔祥明

作者单位： 清华大学

项目金额： 20万元

中文摘要： 高速铁路中大量应用的水泥沥青砂浆，以及包括保温砂浆、防水砂浆在内的各种功能性砂浆，共同特点都是聚合物或沥青这类有机材料与无机水泥基材料共同充当胶凝材料，形成有机无机复合胶凝体系。而聚合物乳液（乳化沥青）加入到水泥浆体中，其凝结硬化机理、微结构形成演化过程等均属未知。本课题针对聚合物-沥青-水泥复合胶凝体系的凝结硬化机理、有机-无机微细结构形成与演化、复合胶凝材料硬化体的静态、动态力学性能、孔隙结构及渗透性能进行了系统研究。课题采用光学显微镜、ESEM观察了乳化沥青-水泥复合体系（Cement Asphalt Composite CAC）早期微结构形成演化过程；采用流变仪研究了CAC早期流变性质以间接描述其微结构；采用微量热法、XRD等技术分析了CAC早期水化动力学及水化产物；采用压汞仪、交流阻抗谱法研究了复合胶凝材料的孔结构及抗渗性；采用MTS及DMA等手段研究了CAC砂浆、净浆等复合体系的静动态力学性能，构建了相应的经验或理论模型；在如上理论研究基础上，探索研究了聚合物改性混凝土的刚性防水技术及采用乳化沥青替代聚合物乳液（胶粉）制备保温砂浆等应用技术，成果具有重要推广价值。

中文关键词： 聚合物；沥青；水泥基胶凝材料；微观结构；力学性能

英文摘要： Organic polymeric materials or (asphalt) have been the essential components in various functional mortars such like heat insulation mortar and water proofing mortar, as well as in the cement asphalt mortar, which is one of the key materials vastly applied in the slab track railway structure. Polymer or asphalt functions as co-binder together with cement to form a kind of organic-inorganic composite binder. However, the hydration and hardening mechanism, the formation and evolution of the microstructure of these polymer incorporated cementitious binder are still not well understood. In this project, the hydration mechanism, microstructure evolution, mechanical properties and permeability of the polymer (asphalt) incorporated cementitious materials were systematically investigated. Microstructure formation and evolution of cement asphalt composite (CAC) were directly observed by optical microscope and ESEM. Hydration kinetics was studied by the micro-calorimeter and hydration products were characterized by XRD. Rheological properties of the fresh CAC were studied to indirectly reflect the microstructure evolution. Pore structure and permeability of the hardened CAC were measured by Mercury Intrusion Porosimetry (MIP) and AC impedance spectroscopy measurement respectively. Static and dynamic mechanical properties of cement asphalt mortars and cement asphalt binders were investigated by using Material Testing System (MTS), and the theoretical or empirical models were constructed to describe the visco-elasticity of the CAC materials. Based on the above-mentioned theoretical investigation, various application technologies were explored, including polymer modification on concrete to achieve structural water- proofing property and development of heat insulation mortar by using asphalt emulsion to replace the traditional used polymer latexes or powders. Proof of concepts of these technologies was given by the demonstration project application. In this project, 6 original research papers indexed by SCI and 9 research papers were published and 1 invention patent was granted.

英文关键词： Polymer; Asphalt; Cementitious materials; Microstructure; Mechanical properties.