传统建筑泥灰类加固材料的性能研究与机理探讨

Study on characteristics and consolidation mechanism of historical mortar materials

人们已经发现一些古建筑所使用的传统材料具有较好的加固作用,其耐久性、强度、与建筑本体的和谐、以及与环境的友好等方面都具有突出的优点。但是由于当时科学技术水平的限制,以及天然材料混合物本身的复杂性,这些传统材料的加固机理一直未被人们充分认识。为了利用和发展传统材料的优势并为古建筑和文物保护服务,本工作选择最具中国特色的以石灰等无机材料为基料,以糯米浆和蛋清等天然生物材料为配料的古代建筑灰浆配方和三合土配方,开展了一系列加固性能研究,并且结合现代SEM和XRD分析仪器,对一些典型的样品进行了微观结构和形貌分析。结果发现,这些古代配方具有现代复合材料的某些特点,即通过无机/有机相互协同的效应,达到了较好的加固效果;重要的是发现糯米浆具有一定的生物矿化的模板作用,即糯米浆的生物大分子对碳酸钙的结晶和生长起到了调控作用,使方解石结晶体的大小和形貌具有一定程度的有序性。本研究为传统材料进一步科学地应用于古建筑和石质文物的修复加固提供了新的思路。

It is found that some traditional materials used on ancient architectures not only have good consolidation abilities, but also have other advantages such as durability, strength, compatibility with the architecture and environment - friendliness. Unfortunately, the consolidation mechanism of these materials was unknown because of the complexity of their components and lack of scientific research in past time. In order to use and develop such tradi- tional materials more effectively for consolidation of historical architectures and relics, some Chinese classical mor- tar formulas were tested. Mortar specimen mimics were prepared following classical mortar and ＂San He Tu＂ formu-las, which consist mainly of inorganic lime and organic sticky rice slurry. A variety of consolidation properties were tested. The morphography and crystallography of typical samples were observed by SEM and XRD, respectively. The results indicated that Chinese classical mortar formulas had properties similar to modem composite materials, but achieved better consolidation properties through a combination between inorganic components and organic com- ponents than if just one of them was used. An important discovery was that the biological molecules in sticky rice slurry controlled the crystallization of calcium carbonate, giving crystals of similar size and shape. This is an example of biomineralization where calcium carbonate functions as the mineral and sticky rice slurry functions as a template. These research results provide new information regarding the application of traditional meterials to the conservation and consolidation of historical structures and relics.