Study On The Law Of Water And Salt Transport And Its Disease Management In The Murals Of Northern Tombs

Tomb mural is an important branch of cultural heritage in china.At present,there are more than 600 mural tombs in various regions of China,the numbers of the northern area accounts for the majority.Among the diseases of tomb murals,the disease of salting out including disruption,detachment,flaking,blister,efflorescence,net cracks and paint loss is the most difficult to control.For the unsteady structure and separating risk,the locale conversation for murals is often adopted at home and abroad.As the complicated microenvironment of the mural,the salting out is mainly caused by the coupling effects with water,thermal and salt.which has been a worldwide academic problem.The analysis of the northern tomb murals was conducted in this work.Combined with the existing environment,this work analyzed the causes of salting out diseases.By means of the simulated tomb murals constructed in Shaanxi Normal University and the vertical soil column in laboratory,the transfer laws of soil water and salt in murals has been studied.Based on the soil characteristics of water and heat,the transport mechanism of the water and salt has been explored.It provided the basis of the protection of cultural relics.In view of the disease of salting out of the mural,this work design a comprehensive protection method based on the system of H₃PO₄-Ba?OH?₂-TEOS for the reinforce by in-situ multipoint crosslinking and inhibition to deal with salting out and apply to the conservation and restoration of the tomb murals.This method was applied to protect the tomb murals.Based on this,this paper was mainly divided into the following six parts.?1?It mainly introduced the classification,construction and manufacturing process of the murals;the influences and the disease type of salting out of the murals;The mural conversation situation and conservation progress of salting out at home and abroad;the significance and the research content of this article.?2?The causes and damage types of salt for the northern tomb murals were analyzed.PHS-3C acidometer,IC,and liquid plastic limit instrument were used to analyze the soil properties and ion content of the different height soil samples.The soil samples of the mural base layer affected by salting out were characterized by SEM,EDX,XRD and laser particle size.The results showed that sulfate and chlorine salt were the mainly factors to result in the salting out of murals and had a certain distribution law in the longitudinal direction.Through the investigation of the disease of salting out from macro and micro perspectives,this work provided references for the subsequent scientific protection.?3?Based on the soil characteristic of water,heat and salt,we explored the law of water and salt transport of the tomb murals.The soil temperature,rate of water content and conductivity of the mural soil with different heights were real-timely monitored by sensors.The result showed that the microenvironment was influenced by the external environmnent and fluctuated obviously by the seasonal features.With the drive of the water in the soil,the soluble salt was longitudinally transferred significantly.The soluble salt dissolve and crystallize repeatedly along with the cyclic change of the temperature and humidity and finally gather on the surface of the mural,which is usually appeared in spring and winter.One-dimensional transport law of water and salt for the sulfate and chlorine salt has been studied by method of vertical soil column.By means of the sensors,the water content and conductivity of the soil with different heights were real-timely monitored.The results showed that the salt conductivity and water content existed negative correlationsalt content and conductivity displayed positively correlated.The soil was characterized by SEM,XRD,IC,etc.The results showed that Na⁺?Ca²⁺?Cl^-?SO₄^2- ion transferred with the water distinctly in the longitudinal direction and mainly concentrated on the surface of the soil within 0-10cm.Based on the study of the transport law of water and salt from macro and micro perspectives,this work has an important theoretical value and practical significance to the protection for the tomb murals.?4?This work developed the system of H₃PO₄-Ba?OH?₂-TEOS for the reinforce of mural by in-situ multipoint crosslinking.The reinforcement effects were compared with the material and commonly used mural protective agents.The reinforcement effects of the color layer and the soil with the simulated samples are analyzed and evaluated after reinforcement by means of spectrophotometer,drawing instrument,universal testing machine,XRD,etc.The results show that this reinforced agent has better permeability,breathability,suitable reinforcement strength and minor color aberration,which is in conformity with the minimum intervention principle and the original principle.Thourgh the drying and watering cycleand thermal cycling,the reinforced samples after soaking are characterized by coating adhesion test.The results show that the method has a better effect of salt tolerance characteristics of aging.The material has been used in the reinforcement of the simulated tomb murals.The soil of reinforced murals are characterized by the means of length of penetration,micro pore structure and resistance to water,etc.The results showed that this method was favorable for deep penetration,in-situ reinforcement and water resistance.It played a role on the reinforcement with the surface of the mural and the pore structure of the soil by the effect of chemical cross-linking.?5?The inhibitory effect of Na₂B₈O₁₃·4H₂O to salting out of the mural had been studied.The simulated mural samples after saline solution soaking had been treated byl-5%concentrations of Na₂B₈O₁₃·4H₂O.The inhibitory action of Na₂B₈O₁₃·4H₂O to deal with the simulated mural samples are characterized by the appearance observation,elastic wave detection,XRD,FT-IR and Zeta Potential.The results showed that appropriate concentration Na₂B₈O₁₃·4H₂O had distinct inhibited effect to the salting out of the mural layers.Comprehensive protection method based on the system of H₃PO₄-Ba?OH?₂-TEOS for the reinforce by in-situ multipoint crosslinking and inhibition has been used in the simulated tomb murals.The treated soil samples were characterized by the methods of SEM,aperture analysis,FT-IR.The pigment layer characterized by the methods of spectrophotometer.The results showed that this method could effectively improve the salting-out inhibition function and had a positive significance to deal with the salting out disease of the mural.?6?The restoration and conservation work were applicated in the tomb murals.According to the disease of disruption and flaking in Dingjiazha No.5 tomb,the appropriate protective measures had been established.Based on the system of H₃PO₄-Ba?OH?₂-TEOS for the reinforce by in-situ multipoint crosslinking and inhibition of salting ou,the protection method was adopted to deal with the disruptive murals.Based on the ZB-F600 return repair agent,the return repair protection method was adopted to deal with the flacking disease of the murals.This method had a good effects and better salting-out inhibition function through a certain period of time.