Lime-based Materials and Practices for Surface Refitting of Cultural Heritage

摘要

Abstract:The surface of cultural heritage and facade of historic buildings represent most values. The conservation of such surfaces need special cares, because most of them are non-structural exposed to extreme weather conditions. The refitting and consolidation delaminated surface were carried out using organic resins, like epoxy resins or cement suspension. However the evaluation in the recent years show such kinds of materials are not chemically compatible with historical materials. Based on inspection on cracks of Huashan乫s Pictographs and other historic buildings in Shanghai and Hangzhou, a new system composed of adhesives and injection grouts based on natural hydraulic lime (NHL) has been developed for refitting and rehabilitation of delaminated surfaces made of natural stones, plaster and bricks. The laboratory researches and trial areas on site have shown the adhesives based on modified NHL have sufficient bonding strength to hold delaminated stone slices and blocks. Furthermore, they show slow setting and carbonation process, almost same heat expansion coefficient as the lime stone and inorganic historical materials. After exposure of 135days on site, the trial areas show neither cracking nor efflorescence. The application of developed adhesives and injection grouts in the restoration work of historic Shanghai plaster gates of Jiuxinli in Hangzhou, Zhejinag Province, has been observed positively. Because of high performance and competitive price against organic resins, they are expected to be an optimal material system in the future for facade restoration of architectural heritage and monuments.