砂岩类文物岩石材料劣化空鼓病害特征及形成机理研究

摘要

To explore the characteristics of surface hollowing and deterioration of historical sandstones,the sandstones of Xi Huang Si Temple were selected as a research subject.Chemical analysis,X-ray and scanning electron microscopy were used to characterize the chemical and mineral components and microstructure of the surface hollowed stone samples.This work revealed the primary causes of hollowing of the sandstones.The first is the existence of a schistose texture in the sandstone and a great amount of expandable clay or plaster sheets.Second,the surfaces of the stone dissolve under the effect of rain,allowing moisture to enter the interior of the sandstones.Inside the sandstone,the parts having a high content of clay or plaster expand rapidly with water,resulting in high pressure expansion.Third,at the locations where the clay or plaster content is high,the coupling strength is low.Hollowing occurs under expansion pressure.This test methods used and hollowing mechanism proposed can provide reference for similar studies.%为了探讨砂岩类文物岩石材料表层劣化空鼓病害的特征和形成机理,以西黄寺建筑砂岩材料为研究对象,采用化学全分析、X衍射、扫描电镜法测试方法对表层空鼓处岩样的化学成分、矿物成分及微观结构进行了分析,依据测试数据系统论述了三个方面空鼓病害的特征。研究结果表明,砂岩类文物岩石材料产生空鼓的原因是岩石内部本身具有层状结构和大量片状膨胀性粘土矿物或石膏;在雨水的作用下使其表面溶蚀,为水进入砂岩内部提供了条件。砂岩内部粘土矿物及石膏较多的部位遇水后发生急剧膨胀,产生较大的膨胀压力,由于粘土矿物及石膏较多的地方,岩层的联结强度又较低,在膨胀压力的作用下便会发生空鼓。本工作的测试方法及空鼓产生的机理可为类似研究提供参考。