盐水比对壁画酥碱病害产生和发展速率的影响

Influence of Salt/Water Ratio on Emergence and Developing Rate of Mural Disruption

目的通过一种无损检测方法研究盐水比对壁画酥碱病害产生和发展速率的影响。方法采用9种盐水质量比(盐水比)制作模拟酥碱病害壁画试块,在恒湿恒温箱中进行干湿循环试验后,用Matlab软件和自编程序对各循环周期后样品数码照片进行分析,获得样品表面高度的三维分布图和量化数据。结果在所研究的时间范围内,盐水比为1:10时,样品未出现明显的酥碱病害;盐水比为2:10和3:10时,模拟出类似于敦煌莫高窟壁画酥碱现象;盐水比为4:10、5:10、6:10、9:10、11:10和13:10时,颜料层出现裂缝、起翘,后地仗层、颜料层整体脱落。结论壁画酥碱病害发展速率呈阶段性,盐水比越大,壁画酥碱病害的破坏风险越大,发展越快。病害发展形貌与软件处理相结合的方法可获得样品酥碱病害发展模型和速率,是一种无损、可量化的评价方法。

The work aims to study the influence of salt/water ratios on the appearance and developing rate of mural disrup- tion in a nondestructive testing （NDT） method. Disrupted mural samples of nine salt/water ratios were made and disposed in the temperature and humidity chamber for wetting-drying cycle test. Digital photos of the mural samples after each cycle period were analyzed by virtue of Matlab soRware and self-programming software, so as to obtain 3D distribution diagrams and quan- tized data at sample surface height. During the studied time range, the sample with salt/water ratio of 1：10 was subject to no obvious disruption damage. The samples with salt/water ratios of 2：10 and 3：10 were subject to the disruption damage similar to that in Mogao Grottoes. The samples with salt/water ratios of 4：10, 5：I0, 6：I0, 9：10, 11：10 and 13：10 were subject to cracking and flaking in pigment layer, then falling off of base layer and pigment layer. Developing rate of the mural disruption was time-phased. The higher the salt/water ratio was, the more risk of mural disruption damage and developing rate would be. Combining the damage developing morphology with Matlab software is a nondestructive and quantifiable method of obtaining the development model and rate of mural disruption.