Evaluation on Weathering Degree of Limestone Artifacts Considering Water Absorption Characteristics.

To realize the non-destructive detection of cultural relics, the limestone relics in Feilai Peak and Yue Temple area in Hangzhou, Chian were selected as inspection objects, and the relationship between the water absorption rate of limestone surface layer, ultrasonic longitudinal wave velocity and surface layer strength were investigated. The fitting model was established according to the variation characteristics among water absorption rate, ultrasonic longitudinal wave velocity, surface layer strength. The evaluation method of surface layer weathering level of limestone relics based on water absorption characteristics was also established based on the fitting model. Results show that the field test data of the superficial strength, longitudinal wave velocity and water absorption rate of limestone have an obvious negative correlation. The weathering grade evaluation method based on water absorption rate of rocks is derived from the field test data, and the rocks are classified into five grades: unweathered, slightly weathered, moderately weathered, strongly weathered and fully weathered. The corresponding water absorption rates range from 0-0.12%, 0.12-0.20%, 0.20-0.61%, 0.61-2.40% and >2.40%, respectively. The accuracy of the fitting results in the area around the seated statue of Luohan and the back of the Huangji tombstone are above 80%, so the weathering grade evaluation method is feasible. The weathering grade evaluation method is completely nondestructive and strictly conforms to the principle of minimum intervention. The conclusions obtained in this study can provide the reference for the subsequent conservation of limestone artifacts. [ABSTRACT FROM AUTHOR]