水泥水化环境中矿物掺合料离子溶出/沉积行为及其调控方法

Supplementary cementitious materials (SCMs) can significantly enhance the workability and durability of concrete, which have become a basic component of modern concrete. Usually, the use of SCMs is mainly based on the reaction theory of alkali or sulfate activation to utilize their potential binding performance. However, although this theory has been developed many years, it still doesn’t make a new breakthrough, which limits the full play of SCMs effectiveness. This project will study the intrinsic reactivity of SCMs with different surface characteristics, which caused by the mineral composition and thermal history. The key impact parameters and mechanism of intrinsic reactivity will be verified, and their evaluation methods also will be established. On the basis, the ions dissolution, migration and precipitation behaviors of SCMs in different curing temperature, pressure and pore solution conditions will be studied, which will build up the correlations between these behaviors and hydration products compositions and structures, and the corresponding reaction mechanism will also be ascertained. Furthermore, the physical and chemical adjusting methods of those behaviors will be proposed, and the high efficient application methods of SCMs will also be designed for their reasonable use in concrete. This research will provide the theoretical and technical supports for the efficient application of SCMs and the development of high performance concrete materials.

矿物掺合料能显著改善混凝土材料工作性与耐久性，已成为现代混凝土的基本组分。人们对于矿物掺合料的使用主要是基于碱或硫酸盐激发反应原理以利用其潜在胶凝性能，该理论多年来虽有所发展但未有新的实质突破，限制了矿物掺合料效能的充分发挥。项目拟从反应热动力学角度，深入研究矿物掺合料表面结构对其反应特性的影响规律，探明影响反应活性的关键参数与机理，建立不同矿物掺合料反应活性评价机制；研究矿物掺合料在不同温度/压力及水泥孔溶液环境驱动下离子溶出、迁移与沉积行为，揭示其与水化产物组成、结构之间关联性及影响机理；在此基础上，探索矿物掺合料水化热动力学行为的化学与物理调控方法，并提出矿物掺合料高效能应用技术以指导其科学应用，为其高效利用及混凝土高性能化发展提供理论与技术支撑。

矿物掺合料能显著改善混凝土材料工作性与耐久性，已成为现代混凝土的基本组分。人们对于矿物掺合料的使用主要是基于碱或硫酸盐激发反应原理以利用其潜在胶凝性能，该理论多年来虽有所发展但未有新的实质突破，限制了矿物掺合料效能的充分发挥。本项目致力于研究不同组成、热历史矿物掺合料内在反应性能的关键影响参数，探明了其在不同养护温度、压力和水泥孔溶液下矿物离子溶出、迁移和沉积机理，建立了矿物掺合料水化热动力学行为与形成的水化产物组成、结构之间的关联性，提出了一种矿物掺合料水化活性评估方法。.项目研究了陶砂粉等矿物掺合料结构与其离子溶出、迁移规律的关联性，探明了贫钙类硅铝质材料火山灰反应活性低的机理，并提出运用C9H21NO3作为络合剂调节陶砂粉的矿物离子溶出特性的方法，可显著增强Al3+、Fe3+的溶出。.研究了不同组成的粉煤灰在不同养护温度和不同浓度碱溶液中的反应性能，揭示了粉煤灰组成中钙、铝的相对含量是影响其离子溶出活性的关键，优选出硫酸钠和C-S-H晶种作为调节反应活性的激发剂，并采用化学合成的方式探明了溶出Al与硅酸盐水泥水化反应的协同机制。.项目根据矿物掺合料水化性能规律，解析了矿物溶解速率是影响其反应性能的关键因素，采用微流控的方法观察到矿物掺合料在H2O/OH-溶液中溶解高度的变化，以此来表征其火山灰反应活性，并结合矿物离子溶出和微流控，提出了其水化反应活性评估新方法。