(1. School of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,Gansu 730000,China;2. Key Laboratory of Mechanics on Disaster and Environment in Western China,Ministry of Education,Lanzhou University,Lanzhou,Gansu 730000,China;3. Northwest Research Institute Co.,Ltd. of CREC,Lanzhou,Gansu 730000,China)
Abstract:Salt damage types of stone cultural relics are related to the water and salt migration controlled by microenvironmental conditions and are mainly affected by the evaporation rate on the rock surface. The sandstone from North Grotto Temple in Gansu Province and Leshan Giant Buddha in Sichuan Province were selected. The capillary rise test of Na2SO4 solution was carried out under conditions of RH = 12%,33%,59% and 76%,in order to simulate the relationship between salt damage characteristics and evaporation conditions. The capillary rise rate,evaporation rate and macroscopic surface phenomena of sandstone were monitored during capillary rise test. Conductivity test,ion content test,elastic wave velocity test,scanning electron microscopy(SEM) test and mercury intrusion porosimetry(MIP) test were performed after capillary rise test. The test results show that:after the capillary rise test,salt layer appears on the sandstone surface of North Grottoes Temple,and with the relative humidity from high to low,the thickness of salt layer gradually becomes thicker. However,with the relative humidity from high to low,the macroscopic salt damage of Leshan Giant Buddha sandstone shows crack propagation,efflorescence,granular disintegration and flaking. Elastic wave velocity test,MIP test and SEM test show that under the condition of RH = 76%,deterioration occurs inside the sandstone of the North Grottoes Temple and Leshan Giant Buddha. Under the condition of RH<59%,there is almost no deterioration inside the two kinds of sandstone. Research results verify that the higher the evaporation rate is,the more easily the salt is carried to the surface,resulting in surface salt damage. On the contrary,the salt is more likely to be trapped inside the sandstone,resulting in internal salt damage.
张虎元1,2,杨盛清1,孙 博1,3,朱江鸿1. 石质文物盐害类型与蒸发速率的关系研究[J]. 岩石力学与工程学报, 2021, 40(S2): 3284-3294.
ZHANG Huyuan1,2,YANG Shengqing1,SUN Bo1,3,ZHU Jianghong1. Research on the relationship between salt damage types and evaporation rate of stone relics. , 2021, 40(S2): 3284-3294.
RUIZ-AGUDO E,MEES F,JACOBS P,et al. The role of saline solution properties on porous limestone salt weathering by magnesium and sodium sulfates[J]. Environmental Geology,2007,52(2):269-281.
[13]
中华人民共和国国家标准编写组. GB/T50123—2019土工试验方法标准[S]. 北京:中国计划出版社,2019.(The National Standards Compilation Group of People?s Republic of China. GB/T50123—2019 Standard for soil test method[S]. Beijing:China Metrology Press,2019.(in Chinese))
[8]
李最雄. 应用PS-C加固风化砂岩石雕的研究[J]. 敦煌研究,1985,(3):156-168.(LI Zuixiong. Research on consolidating weathered sandstone carving using PS-C[J]. Dunhuang Research,1985,(3):156-168.(in Chinese))
[10]
中华人民共和国国家标准编写组. GB/T 50266—2013 工程岩体试验方法标准[S]. 北京:中国计划出版社,2013.(The National Standards Compilation Group of People?s Republic of China. GB/T 50266—2013 Standard for test methods of engineering rock mass[S]. Beijing:China Planning Press,2013.(in Chinese))
[18]
LEWIN S Z. The mechanism of masonry decay through crystallization[J]. Conservation of Historic Stones Buildings and Monuments,1982,1(1):120-144.
[16]
GUPTA S,TERHEIDEN K,PEL L,et al. Influence of ferrocyanide inhibitors on the transport and crystallization processes of sodium chloride in porous building materials[J]. Crystal Growth and Design,2012,65(8):3 888-3 898.
[20]
靳治良,刘端端,张永科,等. 盐分在文物本体中的迁移及毁损机理[J]. 文物保护与考古科学,2017,9(25):104-118.(JIN Zhiliang,LIU Duanduan,ZHANG Yongke,et al. Salt migrations and damage mechanism in cultural heritage object[J]. Sciences of Conservation and Archaeology,2017,9(25):104-118.(in Chinese))
[4]
SCHERER G W. Stress from crystallization of salt[J]. Cement and Concrete Research,2004,34(9):1 613-1 624.
[2]
RODRIGUEZ-NAVARRO C,DOEHNE E. Salt weathering: influence of evaporation rate,supersaturation and crystallization pattern[J]. Earth Surface Processes and Landforms,1999,24(3):191-209.
[12]
HAYNES W M. CRC Handbook of chemistry and physics[M]. Florida:CRC Press Inc.,2016:126.
[1]
GOUDIE A S,VILES H A. Salt Weathering hazards[M]. [S. 1]:Wiley,1997:196-198.
[6]
张虎元,姜 啸,王锦芳,等. 壁画地仗中盐分的毛细输送机制研究[J]. 岩土力学,2016,37(1):1-11.(ZHANG Huyuan,JIANG Xiao,WANG Jinfang,et al. A study on mechanism of capillary-driven transport of soluble salt in mural plaster[J]. Rock and Soil Mechanics,2016,37(1):1-11.(in Chinese))
[7]
姜 啸,张虎元,严耿升,等. 湿度对盐溶液在壁画地仗中的毛细迁移影响研究[J]. 岩土力学,2014,35(2):459-465.(JIANG Xiao,ZHANG Huyuan,YAN Gengsheng,et al. Research on effects of humidity on capillary migration of salt solution in mural plaster[J]. Rock and Soil Mechanics,2014,35(2):459-465.(in Chinese))
[9]
李文军. 北石窟寺地下水与石窟岩体潮湿渗水的关系及地下水治理措施[J]. 敦煌研究,2006,(4):109-114.(LI Wenjun. The relationship between the North grotto Temple Grottoes seepage of groundwater and the damp and groundwater control measures[J]. Dunhuang Research,2006,(4):109-114.(in Chinese))
[11]
GREENSPAN L. Humidity fixed points of binary saturated aqueous solutions[J]. Journal of Research of the National Bureau of Standards,1977,81(1):81-89.
[14]
唐朝生,施 斌,顾 凯. 土中水分的蒸发过程试验研究[J]. 工程地质学报,2011,19(6):875-881.(TANG Chaosheng,SHI Bin,GU Kai. Experimental investigation on evaporation process of water in soil during drying[J]. Journal of Engineering Geology,2011,19(6):875-881.(in Chinese))
[17]
HUININK H P,PEL L,MICHELS M A J. How ions distribute in a drying porous medium:A simple model[J]. Physics of Fluids,2002,14(4):1 389-1 395.
[19]
GUPTA S,HUININK H P,PEL L,et al. How Ferrocyanide influences NaCl crystallization under different humidity conditions[J]. Crystal Growth and Design,2014,14(4):1 591-1 599.
[5]
ZEHNDER K. Long-term monitoring of wall paintings affected by soluble salts[J]. Environmental Geology,2007,52(2):353-367.
[15]
TAN Y,ZHANG H Y,WANG Y. Evaporation and shrinkage processes of compacted bentonite-sand mixtures[J]. Soils and Foundations,2020,60(2):505-519.