浙江古城墙传统灰浆材料的分析研究

摘要

The components of ancient mortars have always been an important research field in historic building conservation .It has been well known that using traditional mortars in conservation projects have many advantages ,such as compatibility and sta‐bility .So ,developing new binding materials based on traditional mortar has become an international study hotspot .With China’ s economic development ,the protection of ancient buildings also began to put on the agenda ,but the understanding on Chinese traditional mortar is limited ,and rare literatures are reported .In the present work ,the authors investigate seven ancient city wall sites in Zhejiang Province in situ ,and subsequently laboratory analysis were carried out on collected mortar samples .The characterizations of mortar samples were made by multi‐density gauge ,XRD ,FTIR ,TG‐DSC and wet chemical analysis .The experimental results showed that :the main component of masonry mortars is calcium carbonate ,the content between 75% ~90% ,and they should be made from relatively pure lime mortar .The raw materials of mortar samples were mainly calcareous quick lime ,and sample from Taizhou city also contained magnesium quick lime .There are four city walls were built by sticky‐rice mortars .It suggests that the technology of adding the sticky rice soup into mortar was universal in the Ming Dynasties . These mortars have lower density between 1 .2 and 1 .9 g・cm‐3 ;this outcome should be the result of long‐term natural erosion . We have also analyzed other chemical and physical characteristics of these masonry mortars .The results can afford the basic data for the future repairmen programs ,development of new protective materials ,and comparative study of mortars .%灰浆材料一直是古代建筑类文化遗产研究的重要对象，文保工程中使用传统灰浆的诸多优点已广为人知，在认识传统灰浆的基础上开发新的石灰基粘结保护材料已然成为国际研究热点。随着中国的经济发展，很多古建筑的保护也开始提上日程，然而关于中国传统灰浆材料的研究颇为薄弱。实地调查浙江地区多座古代城墙遗址，采集灰浆样品，利用多功能密度仪、粉末 X射线衍射仪（X RD ）、傅里叶红外光谱仪（FTIR）、热重‐差热分析仪（TG‐DSC）和湿化学分析技术，对浙江地区7处古城墙灰浆样品进行了分析检测和研究。结果表明：这些古城墙使用的胶结材料是纯“白灰灰浆”，主要成分是碳酸钙，含量在75％～90％之间，其原料主要是钙质生石灰，个别来自镁质生石灰；其中有4座城墙灰浆添加有糯米成分，说明该地区在明代向灰浆里添加糯米等有机材料是建筑城墙十分普遍的工艺技术；检测发现这些建筑灰浆的密度较低，且数值相差较大，在1.2～1.9 g・cm -3之间，应是环境长期侵蚀的结果。同时，也分析了这些砌筑灰浆的其他物化特征，为下一步古城墙本体保护和保护材料的研发，以及传统灰浆全国范围内的比较研究提供了科学依据。