Reducing Ettringite- and Thaumasiteformation in damaged sulfate containing Masonry

在含硫酸盐砌体的维护过程中，至今仍存在严重的错误。造成这种情况的一个原因是，对于许多这些措施来说，缺乏切实可行的维护解决方案。例如，在砖石砌体中采用传统的注水方式，不仅不能阻止破坏反应，而且会导致砖石砌体的承载力下降。初步试验表明，通过插入硅酸酯可以抑制进一步的体积膨胀。将硅酸酯以液体形式插入而不加水，这确保了既不会发生滑动，也不会因含有硫酸盐的材料的水分渗透而造成阻力损失。硅酸酯的确切作用机理及其有效性的基本参数尚不清楚。预计由于硅酸酯的缩聚反应硅是可用的，这允许与现有的氢氧化钙形成二级C-S-H相。它们稳定了结构，降低了液压材料的硅酸盐含量（Ca/ si比）。因此，期望具有更高的抗硫酸盐性。在工作计划中，对二氧化硅酸酯使用的化学/矿物学和物理方面进行了研究，以准备在实践中使用这些材料。规划了优化后的硅酸酯材料在测试对象上的使用。

During the maintenance of sulfate containing masonry still serious mistakes are made today. One reason for this is the fact, that for many of those measures practicable solutions for maintenance are missing. So for example the inserting of water by conventional injections in those masonries does not only show that damaging reaction cannot be stopped, but also lead to less capacity of the masonry. Preliminary tests have shown that it is possible to suppress a further volume expansion by inserting silica acid ester. The silica acid ester will be inserted in its liquid form without adding water, which ensures that neither slide can take place nor loss of resistance will occur caused by a moisture penetration of the sulfate containing material. The exact mechanisms of action of the silica acid ester as well as the essential parameters for its effectiveness are not known yet. It is expected that due to the polycondensation of the silica acid ester reactive silicon is available, which allows the formation of secondary C-S-H phases with the existing calciumhydroxid. They stabilize the structure and reduce the Portlanditcontent (Ca/Si-ratio) of the hydraulic material. As a result of this a higher sulfate resistance is expected. In the work program chemical/mineralogical and physical aspects of the silica acid ester usage are investigated to prepare the use of those materials in practice. The usage of optimized silica acid ester-material on a test object is planned.