Study on Simulated Experiment on Weathering of Carbonate Rock Cultural Relics Accelerated by Atmospheric Acid Gas
Author:Li Liu Liu
Supervisor:qin zuo gong de cai
Stone cultural relics are historical relics made of natural rock.As the physical carrier of historical information.Stone cultural relics have a high historical,artistic and scientific value.In recent years,stone cultural relics are faced with many problems that need to be solved urgently.The research of preservation environment protection scheme of cultural relics based on weathering mechanism becomes extremely important.In the course of exploring the weathering mechanism of stone cultural relics,there are two situations were disregarded:1.The werthering study of atmospheric pollutants on open stone cultural relics in dry areas and stone cultural relics in indoor or outdoor under the combined action of rainfall(no acid)and non-rainfall.2.The study of the weathering mechanism of atmospheric pollutants and greenhouse gas on carbonate rock materials.From a new perspective,this study explores the weathering mechanism of atmospheric pollutants on open stone cultural relics in dry areas and stone cultural relics in indoor or outdoor under the combined action of rainfall(no acid)and non-rainfall.Firstly,by approaching the laboratory simulation test under natural climatic conditions in China,it is discussed that the coupling relationship of acid gases、condensed liquid in pore structure and rock under the combined action of gas adsorption and temperature changes without liquid water(rainwater,dew,surface flowing water,groundwater,etc.).Secondly,in order to investigate the action of SO2,CO2 and NOx on the surface of carbonated cultural relics in the atmospheric environment,the ancient codification samples were selected for case study.Based on the concept of cultural relic protection,the main body of cultural relics could not be observed in high concentration acid gas.Therefore,through the study of lithological characteristics and stone origin in ancient codification samples,the same lithological rock types were selected from the stone chime production sites for the next simulated weathering experiment.Finally,the samples of Lingbi stone were selected for the simulated weathering of acid gas.The surface observation,dissolution rate,phase structure and composition of the samples were compared to study the weathering process of Dendrobium.The results show that under the condition of no direct participation of liquid water,the atmospheric acid gas will cause different degrees of deterioration of the surface of carbonate rock cultural relics.The gas enters into the pores of the rock body through adsorption and capillary cohesion,and dissolves in the capillary water to form an acidic solution,which causes corrosion,secondary salt crystals,powdery peeling and the like in the pores.The simulation experiment provides an opportunity to observe and study the air pollution damage process in the dry area and the indoor stone cultural redics,thus providing a protection basis for the formulation of the stone cultural relic protection method.Obviously,this topic will be of great significance for the study of areas with relatively low rainfall or those that are not directly exposed(such as grottoes and indoors),such as cultural relics and rock weathering fronts.