Influence of stone conservation actions on the long-term weathering behaviour of natural stones

天然石材的腐烂取决于矿物含量、结合行为、孔隙空间条件以及应力类型和风化类型。通过使用保鲜剂，可以影响甚至减少石头的腐烂。本研究项目的重点是随着时间的推移，石头在保存后的腐烂。为了评估自然风化条件下石材保护行动的长期效果，德意志博物馆提供了一项关于25年风化天然石材的自由暴露研究的研究提案。这些样品既未经处理，也用防水剂处理，或者更确切地说，与石材增强剂联合处理。它们为分析保存岩石的岩石衰变和开发基于单侧核磁共振技术的无损检测系统提供了独特的物质基础。通过使用非破坏性测试方法，很少检查石头随时间的风化和活性物质降解之间的深度相关关系。本研究项目旨在发展核磁共振技术，以验证石材保护物质的长期效果。该提案的目的是建立一个经过科学验证的数据库，以生成随时间变化的岩石衰变的风化模型。这一目标的主要数据基础是对天然石材进行自由暴露研究的测量结果。结果由破坏性和非破坏性实验室调查确定。这些值将合并到gis辅助数据库中，并在开放访问的web-GIS界面上可视化，以便将来的用户可以参考生成的知识状态。基于该数据库的预测模型将能够模拟天然石材的随参数变化的风化潜力。本研究项目提供了一种无损检测方法的技术发展，以及修复措施的长期结构化性能测试。

The decay of natural stone depends on the mineral content, the binding behaviour, the pore space conditions as well as the type of stress and type of weathering. By the use of preserving agents, stone decay can be influenced or even reduced. This research project focuses on the stone decay after stone conservation over time. To evaluate the long-term effect of a stone conservation action under natural weathering conditions, the Deutsche Bergbaumuseum provides for this research proposal about 25-year-old weathered natural stones of a free exposure study. These samples are untreated as well as treated with water repellent agents or rather in combination with stone strengthener. They provide a unique material basis to analyse the stone decay of conserved stones and to develop a non-destructive testing measuring system based on unilateral NMR-technique. The depth-dependent correlation between stone weathering over time and degradation of active substances by the use of non-destructive testing methods is rarely examined. This research project aims to develop the NMR-technique in order to validate the long-term effect of stone protective substances. Aim of this proposal is the final conception of a scientifically proven database to generate weathering models for time-dependent stone decay. The main data basis for this aim consists of the measurement results of the analysed natural stones of the free exposure study. The results were determined by destructive as well as non-destructive laboratory investigations. These values will be merged in a GIS-assisted database and visualised on a web-GIS interface with open-access, so that future users can refer to the generated state of knowledge. Forecast models based on this database will enable the simulation of the parameter-dependent weathering potential of natural stones. This research project provides a technological development of a non-destructive testing method as well as a long-term structured performance test for repair measures.