传统三合土制作工艺的科学机理研究

In the history of Chinese constructions, tabia had been recognized as the one of most common binding materials. There are many historical tabia buildings heritages been well-preserved to now in China, and most of them have immeasurable artistic or scientific value. However, the most traditional existing tabia buildings lie in a very bad condition and need imperative protection, due to the natural and man-made destructions came through hundreds or thousands of years. In virtue of very little historical and scientific literature records, people have been lacking of enough understanding to manufacturing techniques and scientific mechanism of the traditional tabia, which have seriously restricted the application of this traditional concrete on the protection of ancient buildings. .In the research project, the basic physical properties, material composition, chemical constitution and mechanical strength of the traditional tabia were investigated to regain the traditional production process of tabia referenced to historical documents. Next, the scientific mechanisms of traditional tabia are studied using the simulated samples. Finally, the modification research of traditional tabia is carried out to improve its performance. This research project can reproduce Chinese traditional tabia technologies, which are expected to be widely used in the protection engineerings of ancient architectural heritage.

三合土是中国古代历史上使用最悠久的主要建筑材料之一，被广泛应用于古代建筑构件中。我国境内遗留至今的古代三合土建筑数量众多，很多具有重要的历史、艺术和科学价值。但在数百甚至上千年的自然和人为因素破坏下，现存三合土建筑保存状况普遍较差，亟需加以抢救保护。囿于中国古代的文化传统和研究现状，人们对我国传统三合土制作工艺和科学机理等问题缺乏清晰认识，严重制约了传统三合土在古建筑保护中的应用。.本项目从传统三合土的材料特征和化学成分入手，研究传统三合土的基本物理性质、物质组成、化学成分和机械强度等信息，结合历史文献复原三合土的传统制作工艺。在此基础上利用模拟样品研究三合土传统制作流程与工艺蕴含的科学机理。最后，为克服传统三合土的一些缺点，尝试对其进行改性研究。本项目不但能够重现我国传统的三合土技术，而且有望将其广泛应用于古建筑遗产保护工程中。

我国历史上遗留下来许多三合土建筑遗产，如古代城墙、墓葬、水利工程、炮台、居住建筑等，这些古建筑不仅承载着中国传统文化的历代传承，还蕴含着我国古代匠人的科学智慧。因此，从科学的角度深入认识三合土建筑技术、保护古建筑，在古建筑因工业化污染、城市化扩张而逐渐破损的今天，显得尤为紧迫。基于此，该项目主要致力于传统三合土制作材料与工艺，恢复古代建筑技艺，以及传统三合土制作工艺科学机理等方面的研究。这些研究无论是从建筑技术史，还是古建筑保护的角度看，都有十分重要的意义。. 研究结果表明，郑州商城遗址的夯筑材料由胶结材料碳酸钙和石英骨料组成，碳酸钙系由人工烧制的生石灰碳化而成，说明我国在商代已出现石灰烧制技术。胶结材料与骨料的质量比为1:2.68，表明郑州商城遗址出土的夯筑灰土材料是灰、砂二元“三合土”结构，说明当时三合土技术处于早期应用阶段。浙江古代海防炮台三合土材料的研究表明，三合土技术在明清时期已然发展成熟，不仅存在各种配比的灰、土二元三合土，灰、土、砂（石）三元三合土，还有许多添加天然有机添加剂的三合土。. 糯米浆和糖水三合土研究表明，这些有机添加剂在生物模板和生物矿化作用下，使三合土的颗粒分布更加均匀，排布更加致密，碳化反应生成的晶体粒径更小，而且可能更有利于三合土中C-S-H材料的生成，进而提高三合土的整体强度和耐候性。