Molecular mechanisms of mechanical and chemical corrosion on cement-bound materials

在这个项目的框架内，将对水泥结合材料的机械和化学腐蚀的分子机制进行研究。为此，在硅片上合成了超薄的水化硅酸钙相(C-S-H相，作为水泥层的模型)，并将硅片在弹性范围内弯曲。由此产生的应力(在C-S-H阶段)可以与拉伸试验机中的单轴长度变化进行比较。用红外光谱研究了应力作用下C-S-H相界面处的各种交换和输运过程(作为化学腐蚀的模型)。这里，选择的红外传感器分子被使用，这些分子特别吸附在表面的缺陷上。此外，利用密度泛函理论(DFT)进行了无参数计算，因为它们可以与实验模型衬底进行理想的匹配。机械和化学腐蚀方面的新发现将为改进C-S-H相的合成提供机会，以使它们在机械和化学上更具抗应力能力。

Within the framework of this project, the molecular mechanisms of mechanical and chemical corrosion on cement-bound materials will be investigated. For this purpose, an ultra-thin calcium silicate hydrate phase (C-S-H phase, as a model for a cement layer) is synthesized on Si wafers and the Si wafers are bent in the elastic range. The resulting stress (in the C-S-H phase) can be compared with a uniaxial length change in a tensile testing machine. Under stress, various exchange and transport processes (as a model for chemical corrosion) at the C-S-H phase interface are investigated using infrared spectroscopy. Here, selected infrared sensor molecules are used which adsorb particularly on defects on the surfaces. In addition, parameter-free calculations are carried out using the density-functional theory (DFT), since they can be ideally matched with the experimental model substrates. The new findings on mechanical and chemical corrosion will provide opportunities to improve the synthesis of the C-S-H phases in order to make them mechanically and chemically more stress-resistant.