侵蚀性离子对混凝土材料中Al掺杂C-S-H凝胶微结构和性能的影响机理

C-S-H凝胶是混凝土材料的主要水化产物（占60%~70%），影响着混凝土的力学和耐久性能。在混凝土胶凝浆体水化过程中，Al3+可进入C-S-H凝胶结构中形成Al掺杂C-S-H凝胶，Al3+的掺杂量和配位状态影响其微结构和性能。本课题针对Al掺杂C-S-H凝胶微结构形成机制和侵蚀性离子（Mg2+、SO42-、Cl-）作用下微结构演变机理尚未明确的问题，采用NMR、TEM-EDS、DSI等现代测试技术，研究胶凝材料组成和水化环境对Al掺杂C-S-H凝胶微结构和性能的影响机理。并在此基础上，研究侵蚀性离子单独和耦合作用对Al掺杂C-S-H凝胶微结构、力学性能和氯离子吸附固化性能的影响机制。探明海水侵蚀环境下具有良好力学性能和氯离子吸附固化性能的Al掺杂C-S-H凝胶微结构特征，提出基于胶凝浆体微结构调控的混凝土耐久性提升方法。研究成果可为海工水泥的开发和耐久性混凝土的设计提供参考依据。

C-S-H gel, the main hydration product of concrete materials, affects the mechanical properties and long term durability of the concrete. During the hydration of cementitious materials in concrete, Al3+ ion can enter into the molecular structure of C-S-H gel and form the Aluminum substituted C-S-H gel, in which the substitution amount and coordination state of Aluminum affect the microstructure and properties of the gel. To prove the formation mechanism of Aluminum substituted C-S-H gel and its microstructure evolution under the attack of corrosive ions, this project is about to study the effects of cementitious materials composition and hydration environment on the microstructure and properties of Aluminum substituted C-S-H gel, using test methods such as NMR, TEM-EDS and DSI. On the basis these research, this project is going to further study the effects of corrosive ions attack (separate or coupling) on the microstructure, mechanical properties and chloride absorption/fixation property of Aluminum substituted C-S-H gel, to find out the microstructural features of the Aluminum substituted C-S-H gel which shows favorable mechanical properties and chloride absorption/fixation property in seawater environment. Finally, the approach to increase the concrete durability based on the modification of microstructure of the pastes was propose. The achievements can provide as a theoretical reference for the development of marine cement and design of durable concrete.