Abstract
AbstractWater plays a vital role in deteriorating stone heritage, especially those carved into vertical rock slopes. Southeast China is home to numerous limestone rock-hewn heritages, many of which showcase diverse deterioration patterns on their facades. Nevertheless, due to the large scale of this heritage and the limitations imposed by the principle of minimal intervention in practices, there is still a lack of practical strategies for understanding moisture distribution. Therefore, this study aims to analyse the moisture distribution of limestone rock-hewn statues via in situ detection employing a portable hygrometer and laboratory calibration based on the gravimetric method and regression analysis. The in situ determination was conducted in the Ciyunling statues niche 1 (World Heritage Site), which was hewn in the Wuyue states (942 CE). Thirty-six measuring areas were evenly planned on the niche's façade, with 20 moisture readings obtained from each measuring area. Additionally, the surface hardness of the typical area of statues was examined using a non-invasive Leeb hardness tester and Kruskal–Wallis H test to assess the impact of moisture on deterioration. The findings reveal that the statues' moisture content is higher than the background wall between the statues, signalling a greater potential for deterioration on the surface of the limestone statue. The primary source of moisture appears to be gaseous water in the atmosphere, which accumulates in the micropores through capillary condensation. Furthermore, the statistically significant differences in surface hardness between the chest/shoulder of statues and the root of the façade highlight the softening effect of moisture on the foundation of the limestone statues. Hence, the methodology utilised in this study serves as a viable approach for examining moisture levels and the extent of deterioration in rock-hewn heritage structures.
Funder
Postdoctoral Science Preferential Funding of Zhejiang Province, China
Publisher
Springer Science and Business Media LLC
Subject
Geology,Geotechnical Engineering and Engineering Geology,Civil and Structural Engineering
Reference41 articles.
1. Al-Omari A, Beck K, Brunetaud X, Török Á, Al-Mukhtar M (2015) Critical degree of saturation: a control factor of freeze-thaw damage of porous limestones at Castle of Chambord, France. Eng Geol 185:71–80. https://doi.org/10.1016/j.enggeo.2014.11.018
2. ASTM [American Society for Testing and Materials] (2020) Standard test method for splitting tensile strength of masonry units (C1006/C1006M—20a). Retrieved from https://compass.astm.org/document/?contentCode=ASTM%7CC1006_C1006M-20A%7Cen-US
3. Barbosa MTG, Rosse VJ, Laurindo NG (2021) Thermography evaluation strategy proposal due moisture damage on building facades. J Building Eng 43:102555. https://doi.org/10.1016/j.jobe.2021.102555
4. Camaiti M, Bortolotti V, Fantazzini P (2015) Stone porosity, wettability changes and other features detected by MRI and NMR relaxometry: a more than 15-year study. Magn Reson Chem 53(1):34–47. https://doi.org/10.1002/mrc.4163
5. Chang Q (1995) Rock-hewn statues of ZIxian temple on the Ciyunling, Hangzhou. Cultural Relics 10:70–79+98. (in Chinese)