TY - CONF A1 - Rübner, Katrin A1 - Stuff, Maria A1 - Großmann, Karsten A1 - Pniok, Nicole A1 - Dreisow, Bianca T1 - A silica-based protective system modified with rock powder for the preservation of tuff stone N2 - Tuffs are lightweight and porous pyroclastic rocks composed of a volcanic ash matrix containing pumice and rock fragments, quartz, sanidine and other individual crystals, zeolites, and clay minerals. Due to their low density and high porosity, tuff stones are easy to work with and transport. They have been used as construction material in many historical buildings in Germany. However, most tuff stones exhibit poor resistance to weathering due to their morphology and porosity. If the physico-chemical degradation of the stones is already well advanced, ensuring the safety of the buildings often requires extensive stone replacement. However, this contradicts the fundamental principle of conservation, which prioritises the preservation of the original material. In a recently completed research project, a silica-based protective system modified with rock powder was developed for the preservation of tuff stone. Suitable colloidal silica dispersions and modified rock powders customised produced from tuff waste were used. The protective system was optimised to reduce the capillary water absorption of tuff while maintaining its water vapour diffusion properties, to build a durable protective system-tuff bond, and to achieve a visual and tactile resemblance to tuff. The protective system was developed at laboratory scale. It was subsequently applied to a test area at a restoration site in Berlin-Zehlendorf, Germany, to assess its performance under outdoor conditions. By applying the new protective system, the historic building structure is better preserved, tuff stone resources are saved, and tuff waste is effectively recycled. T2 - STONE 2025 - 15th international congess on the deterioration and conservation of stone CY - Paris, France DA - 08.09.2025 KW - Protective system KW - Rock powder KW - Silica sol KW - Stone preservation KW - Tuff stone KW - Tuff waste recycling PY - 2025 SP - 743 EP - 749 AN - OPUS4-64748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -