ABSTRACT

The conservation of historic structures must be carried out through treatments that use materials which are compatible with the originals. In recent years, nanolime has been considered one of the most promising products for the consolidation of calcareous substrates due to its characteristics of high compatibility with the treated substrate and durability. The effectiveness of nanolime products has been proven for superficial consolidation treatments (e.g. plasters and wall-paintings), and research nowadays is focused on the study of the in-depth consolidation effectiveness of porous substrates. The aim of this paper is to undertake preliminary investigations of compatible nanolime treatments for Indiana limestone (US) and a weathered marble. Nanolime was synthesized by anion exchange resins and dispersed in isopropanol and ethanol. The consolidation effectiveness is assessed by studying changes in porosity, drilling resistance, surface cohesion and aesthetic appearance (colour). Results showed that nanolime yielded the highest consolidation effectiveness when treated samples were kept in high relative humidity environments (~75%RH) or regularly sprayed with carbonated water in a laboratory environment (~50%RH). These results suggest that for an on-site consolidation treatment with nanolime in dry environments, treated surfaces could be regularly sprayed with carbonated water to increase consolidation effectiveness.

摘要

对历史建筑的保护必须通过使用与原件兼容的材料进行处理。近年来，由于其与被处理基质的高度相容性和耐久性，纳米石灰被认为是钙质基质固结最有希望的产品之一。纳米石灰产品的有效性已被证明可用于表面固结处理（例如灰泥和墙壁涂料），并且如今的研究重点是对多孔基材的深度固结效果进行研究。本文的目的是进行印第安纳石灰石（美国）和风化大理石的兼容纳米石灰处理的初步研究。用阴离子交换树脂合成纳米石灰，并分散在异丙醇和乙醇中。通过研究孔隙率，抗钻性，表面内聚力和美学外观（颜色）的变化来评估固结效果。结果表明，将处理过的样品保存在高相对湿度环境（〜75％RH）中或在实验室环境中定期用碳酸水喷洒（〜50％RH）时，纳米石灰的固结效果最高。这些结果表明，对于在干燥环境中使用纳米石灰进行现场固结处理，可以定期用碳酸水喷洒处理过的表面，以提高固结效果。结果表明，当将处理过的样品保存在相对湿度较高的环境（约75％RH）或在实验室环境中定期用碳酸水喷雾（约50％RH）时，纳米石灰的固结效果最高。这些结果表明，对于在干燥环境中使用纳米石灰进行现场固结处理，可以定期用碳酸水喷洒处理过的表面，以提高固结效果。结果表明，将处理过的样品保存在高相对湿度环境（〜75％RH）中或在实验室环境中定期用碳酸水喷洒（〜50％RH）时，纳米石灰的固结效果最高。这些结果表明，对于在干燥环境中使用纳米石灰进行现场固结处理，可以定期用碳酸水喷洒处理过的表面，以提高固结效果。