北石窟寺表面防风化材料筛选

Research on the selection and application of weathering prevention materials for Beishiku Temple

甘肃石窟分布广泛,洞窟大多开凿在砂岩上。在长期自然环境作用下,砂岩石窟表面风化严重,有部分区域甚至风化成砂土,砂岩石窟浅表层风化防治将成为重要的研究方向。本工作针对北石窟寺砂岩典型风化病害,选用0.5%羟甲基纤维素、5%砂岩加固材料、1.5%有机硅改性丙烯酸、1.5%丙烯酸、20%纳米SiO_(2)、10%正硅酸乙酯、3%PS共7种保护材料,基于室内试验测试这些材料的防风化性能,以加固前后宏观和微观特征进行定性描述,以色度、体积变化率、波速、表面硬度、抗压强度、透气性和吸水性作为加固定量评价指标,优选出砂岩加固材料、有机硅改性丙烯酸、纳米SiO_(2)、PS和正硅酸乙酯作为北石窟砂岩表面防风化加固建议材料。研究结果为北石窟寺砂岩质石窟表面防风化技术研发与应用积累了基础研究数据。

Grottoes are widely distributed in Gansu Province and most of them were excavated in sandstone.Due to long-term influences of natural environment,the surfaces of sandstone grottoes have been seriously weathered,with some areas even becoming powdery.Therefore,prevention and control of weathering of sandstone grottoes will become an important research direction.This study paid attention to the typical weathering disease of sandstone in Beishiku Temple.We selected seven kinds of prevention materials including 0.5%hydroxymethyl cellulose,5%sandstone reinforcement material,1.5%silicone-modified acrylic acid,1.5%acrylic acid,20%nano-SiO_(2),10%tetraethyl orthosilicate and 3%potassium silicate.Based on laboratory tests of the weathering prevention performances of these materials(the macro-and micro-characteristics before and after reinforcement were qualitatively described,and chromaticity,volume change rate,wave velocity,surface hardness,compressive strength,air permeability and water absorption were used as quantitative evaluation indexes of reinforcement),we finally selected sandstone reinforcement material,silicone-modified acrylic acid,nano-SiO_(2),potassium silicate and tetraethyl orthosilicate as recommended materials.The results provide basic research data for the research and application of weathering prevention technology for Beishiku Temple.