From common clays to Geopolymer binders - crystallographic and building material technology-based investigations

尽管普通粘土在相含量、结构和颗粒形态方面是最不均匀的天然原料，但关于普通粘土的热活化和碱性活化的最新实际科学知识仅限于现象学描述。然而，由于它们的化学和矿物学成分以及未来的可用性，它们似乎特别适合碱性活化，因此，用于地聚合物粘合剂的开发。目前，普通粘土的材料特性和工艺参数之间的关系还没有研究基于地聚合物粘结剂的砂浆和混凝土的最终性能。一种更好地理解这些现象的方法是将模型粘土矿物和真实普通粘土的研究结合起来，这将是本研究项目的主要重点。本研究的重点是研究使用煅烧的普通粘土作为生产地聚合物粘合剂的碱性活化源材料时发生的反应，这取决于粘土矿物的相含量和晶体结构。为了在性能基础上预测天然粘土混合物的原料行为，将把大部分注意力放在元粘土矿物和热不活化粘土矿物之间的相互作用上。此外，可以从这些研究中获得有关元粘土活化和反应性的基本知识，这些研究也可以在使用煅烧粘土的胶凝砂浆和混凝土中考虑。此外，由于这些系统的复杂性，地聚合物粘合剂和砂浆最初是人们感兴趣的中心。通过申请人的方法，可以首次通过自然和工程科学方法系统地推导出由煅烧的普通粘土制成的地聚合物粘合剂和砂浆的质地，孔隙率/渗透率，表面结构，碱度和选定的机械性能。项目目标应通过两个相互作用的工作包来实现，这两个工作包涉及地聚合物粘结剂和砂浆的矿物学和晶体学特征值、工艺参数和建筑材料工艺性能。

Up to date actual scientific knowledge about the thermal and alkaline activation of common clays is restricted to a phenomenological description, despite common clays being the most heterogeneous, natural raw materials in terms of their phase content, structure and particle morphology. However, due to their chemical and mineralogical composition as well as for the future availability they seem to be particularly suitable for an alkaline activation, and thus, for the development of Geopolymer binders. Currently, the relation between material properties and process parameters for common clays has not been investigated with respect to the resulting properties of mortars and concretes based on Geopolymer binders. One approach to gain a better understanding of these phenomena is the combination of investigations of model clay minerals and real common clays, which will be the main focus of this research project. The focus of this study will be on the investigation of the occurring reactions when using calcined common clays as an alkaline activation source material for the production of Geopolymer binders dependent on phase content and crystal structure of the clay minerals. Most attention will be paid on the interaction between metaclay minerals and thermally not activated clay minerals in order to predict the raw material behaviour of the naturally occurring clay mixtures on a performance basis. In addition, fundamental knowledge about the activation and reactivity of metaclay can be derived from these investigations which could be also considered in cementitious mortars and concretes where calcined clays are used.Furthermore, Geopolymer binders and mortars are initially in the center of interest, due to the complexity of these systems. By the applicants approach strong and fundamental statements about texture, porosity/permeability, surface structure, alkalinity and selected mechanical properties of Geopolymer binders and mortars made of calcined common clays, can be systematically derived for the first time generated by means of natural and engineering science methods. The project objectives shall be achieved by two interacting working packages, which deal with mineralogical and crystallographical characteristic values, process parameters and construction material technological properties of Geopolymer binders and mortars.