Reducing Ettringite- and Thaumasiteformation in damaged sulfate containing Masonry

在维护含有硫酸盐的砖石过程中，至今仍会出现严重的错误。造成这种情况的一个原因是，对于这些措施中的许多措施，缺乏可行的维护解决方案。因此，例如，在这些砖石中通过传统的注入水不仅表明破坏反应无法停止，而且还会导致砖石结构的承载能力降低。初步测试表明，通过插入硅酸酯可以抑制进一步的体积膨胀。硅酸酯将在不加水的情况下以液体形式插入，这确保了不会发生滑动，也不会因为含有硫酸盐的材料的湿气渗透而导致阻力损失。硅酸酯的确切作用机制以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次C-S-H相。它们稳定了结构，降低了水工材料的波特兰含量(钙硅比)。因此，预计会有更高的硫酸盐抗性。在工作计划中，对硅酸酯使用的化学/矿物学和物理方面进行了调查，为这些材料在实践中的使用做好准备。计划了优化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.