中国古建筑石灰灰浆的光谱分析技术

石灰是中国古代最早使用的重要胶凝材料,广泛应用于房屋、墓葬、城墙、堤坝等古代建筑工程中。古人还在石灰灰浆中添加糯米浆、动物血液、植物汁液、红糖、桐油、纸筋、秸草等有机材料以增进其性能。此外,中国古代还使用石灰、粘土和砂石组成现在称为"三合土"的混合石灰材料以构筑墓葬、城墙和水利工程等建筑墙体。在古建筑遗址的修复和保护工作中,本着"修旧如旧"的原则,必须对古建筑修建所采用的原材料和施工工艺进行分析研究,从而为修复工作提供科学可靠的依据。本文综述了在对中国古代建筑石灰灰浆的分析中所采用的光谱分析技术,包括拉曼光谱、红外光谱、X射线衍射和X射线荧光光谱,以及扫描电子显微镜、热重分析等其它一些分析技术,讨论了各种分析技术的用途、优势和劣势。     

汉中山河堰二堰和羊头堰灰浆的分析研究

陕西汉中三堰(山河堰、五门堰、杨填堰)在2017年10月被确认成功申报世界灌溉工程遗产并授牌,其中山河堰是汉中地区最早的灌溉工程。20世纪80年代,在水文考古普查时发现,山河堰砌体以木桩砌石为骨架,使用可能加入桐油、糯米浆的黄泥、沙、石灰搅拌而成的三合土作为填充物。为深入探究山河堰灰浆的成分和科学机理,对山河堰的灰浆样品进行了成分分析,并检测了样品的年代信息。该研究在山河堰二堰东堤和羊头堰取样,利用X射线衍射分析(XRD)、傅里叶变换红外光谱分析(FTIR)、差热分析、扫描电镜、岩相等科技手段,检测分析样品的组成成分。另外,利用碳-14检测对山河堰二堰灰浆进行断代分析。分析结果表明,山河堰二堰东堤石条粘合物经年轮校正后的年代为公元1150年—1226年(南宋时期),山河堰二堰东堤粘合物和夯土以及羊头堰粘合物的无机成分主要为方解石、石英及少量长石。其中,粘合物中石灰的添加量较高,夯土中石灰的添加量较低。红外分析和热分析结果表明,粘合物和夯土中似乎添加了某种有机物,结合文献资料分析该有机物很有可能为糯米浆。热分析结果显示,800℃以上出现的放热峰为水化硅酸钙的特征峰,推测石灰与水发生反应生成水化硅酸钙。水化硅酸钙能在水中或潮湿的环境中更好地硬化,它是水利工程可以保存数千年的主要原因。电镜检测结果显示,样品中尚未被碳化的消石灰(Ca(OH)2)脱水形成羟钙石晶体。另外,灰浆中加入的有机物和灰浆的缓慢碳化都有助于增强灰浆砌体的自我修复能力和抗风化能力,延长水利工程的使用期限。采用各种科学手段对山河堰灰浆进行科学研究,有助于探明水利工程灰浆材料的组成及其科学机理,为山河堰等水利工程遗产的保护修缮奠定科学基础,并可为现代水利工程材料的改良提升提供有益的启示。     

皖南牌坊传统灰浆的科技研究

采用FTIR,XRD,SEM等技术,对皖南牌坊上的传统灰浆材料配方进行了初步研究。结果表明,牌坊灰浆样品为石灰掺桐油或糯米而形成的有机-无机复合材料。桐油灰浆强度的形成主要源于灰浆中石灰的碳化反应、桐油与氧气的交联反应和Ca2+与—COO-的配位反应以及由此而形成的致密片层状有机-无机复合结构。糯米淀粉对灰浆碳化过程的调控作用而形成的细密的微观结构是糯米灰浆具有良好性能的微观解释。     

传统糯米灰浆碳化过程中Liesegang环的形成机理研究

采用FTIR,XRD,SEM等技术,对传统糯米灰浆碳化过程中出现的Liesegang环现象进行了初步研究。结果表明,使用陈化石灰和糯米浆制备的糯米灰浆在碳化过程中能形成较明显的Liesegang环;陈化石灰-糯米灰浆固化后的极小孔隙,是传统糯米灰浆中Liesegang环形成的本质原因,其形成机理符合延迟成核理论。     

青海热贡地区传统建筑彩画颜料光谱特征分析研究

青海省热贡地区是安多藏区藏式建筑彩画艺术的重要产地,作为热贡艺术的重要组成部分影响甚广。热贡地方建筑彩画不仅是附着建筑栋梁之上的艺术瑰宝,更是一项延续至今的传统技艺,至今仍有大批传统匠人画师从事相关行业。热贡地方建筑彩画有独立的用色方法和颜料制作工艺,对其所用传统颜料进行科学检测是系统研究该地区建筑彩画的基础性工作,在进一步研究热贡地区建筑彩画的制作工艺和艺术特色,传承地方建筑彩画技艺和完善保护政策等方面具有积极意义。通过对同仁市隆务寺夏日仓行宫火供殿所用当地传统建筑彩画颜料的采样,运用X射线荧光光谱、X射线衍射分析、激光显微拉曼光谱分析等多种实验分析方法,对颜料样品进行分析,测定其主要显色物质和成分占比。结果表明,热贡地方建筑彩画所用颜料多为无机颜料;蓝色颜料主要是人造群青;绿色颜料的主要矿物组成为绿土,显色物质为蒙脱石,存在将植物色染料加入当地所产的富镁蒙脱石中混合使用的可能性;红色颜料的主要矿物组成为铁红（赭石类红土）,通过焙烧富铁矿土来人工合成,材料来自于当地吾屯村所产红色赭石类粘土;黄色颜料主要矿物组成为密陀僧、硫磺及其他植物色染料制备而成;黑色颜料为碳黑,符合木炭黑的性状特征;白色颜料主要为生石灰及氧化镁粉,并在其他颜料中广泛使用石灰及氧化镁粉作为调色颜料;推测部分样品中含有包金土及植物色素染料、其他人工合成颜料的可能性。整体来看,热贡地区建筑彩画所用颜料成本价格较低,制取难度不大,来源大多是当地常见的矿土料和动植物染料,传统的制料工艺较简单,颜料多呈现为组分复杂的混合物状态;密陀僧、包金土和群青等颜料多来自于内地及国外,颜料人工合成的历史较早,反映出热贡地区建筑彩画在颜料使用上不仅使用本土材料制备,也广泛使用外来颜料的历史传统,为进一步研究热贡地区建筑彩画领域内汉、藏等多民族文化交往、交流、交融历史提供了良好实证材料。     

红外光谱定量分析古代漆膜的可行性研究

漆器是中国文化遗产的一个重要组成部分,贯穿中国古代历史发展的整个过程。为了改善生漆的性能,古人将干性油与生漆混合使用,所添加干性油的比例直接影响生成漆膜的性能。由于相关历史文献的匮乏和考古出土古代漆器的老化降解,当前的科技分析主要是定性分析漆膜材料成分,而对于油/漆比例方面的研究却非常少。为了了解古代漆器在制作时所添加的干性油与生漆比例,建立一种定量分析古代漆器漆膜油/漆比例的方法是十分必要的。通过制作标准样品,分别采用FTIR-ATR和NIR对古代漆膜进行了定量分析,结果表明FTIR-ATR在漆膜老化严重的情况下,将不能达到定量分析的目的。而采用近红外光谱技术结合化学计量学方法建立的PLS模型,能对古代漆膜制作时的油/漆比例进行快速、无损的定量分析。结果表明PLS定量模型具有良好的稳定性和预测性,校正均方差(RMSEC)、预测均方差(RMSEP)和交叉验证均方差(RMSECV)均较低,相关系数R_c,R_p和R_v均在0.99以上。将该方法应用到考古发掘出土漆器漆膜材料的分析中,通过PLS定量模型计算出古代漆膜制作时的干性油添加量,确定了不同时代和不同地区漆器制作所用油/漆比例的不同,为解读古代中国的"油漆"技术提供科学依据,为漆器文物的保护修复提供一些数据支撑。     

北京故宫养心殿燕喜堂及西围房建筑彩画的分析研究——一种检测颜料和胶结物的集成检测方法

北京故宫是现存规模最大、保存最完整的木结构古建筑群。2015年底,故宫养心殿启动研究性保护修缮工程,燕喜堂是养心殿的后殿西耳房,是此次维修的重点对象之一。彩画是古建筑的重要组成部分,不仅具有美化装饰的作用,更有对木材的防腐保护功能。为了能更好地辅助燕喜堂及西围房建筑彩画的保护与修复,需要对彩画原始材料以及工艺进行检测研究。使用一套集成检测方法：包括样品横截面分析、扫描电子显微镜背散射及能谱技术、拉曼光谱技术、荧光染色法、酶联免疫法、免疫荧光法以及热裂解气相色谱法,分析了故宫养心殿燕喜堂及西围房建筑彩画样品的颜料、沥粉、胶结材料的成分,以及结构关系。结果表明燕喜堂西围房使用的颜料有朱砂、铁红、群青、石青、石绿以及副氯铜矿型铜绿;沥粉的无机组成为石英、滑石、白垩或白云石。胶结材料检测结果发现彩画地仗层中普遍掺加了桐油,颜料层中掺加了动物胶。梁上彩画除了表面图案,地仗层底部还有一层朱砂颜料,同时地仗层内部也不规则地发现朱砂颜料。此外,表层红色颜料通常由两层颜料组成,内层的显色成分是铁红和朱砂,颜料颗粒直径1 μm左右,外层颜料由朱砂组成,颜料颗粒大小不一,直径1～30 μm范围内。上述检测结果不仅可以部分看出燕喜堂及西围房建筑彩画的工艺特征,也表明该集成检测方法可行、所需样品量少,是一种经济实用的彩画文物检测方法。     

老化丝织品的红外光谱分析研究

古代丝织品老化程度的检测有助于了解丝织品的保存状况及保护方法的选择与改进,通过红外光谱分析对丝织品老化原因及程度进行了研究。样品为经光老化、热老化和水解老化的白色丝织品和出土于湖北、内蒙古、青海的古代丝织品。对这些样品进行了显微红外分析,结果表明,红外光谱分析虽然只是提供半定量分析,但是对于发生了水解老化的丝织品来说,由于羧基含量的增加,红外分析能很容易提供定性及较好的半定量的分析结果,因此对于出土古代丝织品保存状况及老化机理的研究来说很有实用价值。     

利用X射线衍射光谱研究丝织品的老化

中国考古出土的丝织品数量大,种类丰富,是中国古代文化遗产的重要组成部分,但由于丝蛋白易于降解老化的材料特性,有许多保护问题需要研究解决。对古代丝织品老化程度、老化特征的分析检测有助于了解丝织品的保存状况,并可为保护方法的选择与改进提供帮助。文章通过X射线衍射分析对丝织品老化特征及结晶度的变化进行了研究。样品为经光老化、热老化和水解老化的白色丝织品和出土于湖北、陕西、内蒙古、青海的古代丝织品。X射线衍射分析结果表明,X射线衍射分析可以揭示丝织品的老化作用过程和老化特征,以及相应结晶度的变化,对于出土古代丝织品保存状况及老化机理的研究来说具有实用价值。同时还可为了解古代染织工艺的发展提供信息。     

中国北方古建油饰彩画中绿色颜料的光谱分析

古建油饰彩画中颜料成分的分析鉴定是古建维修、保护的重要基础工作。文章利用X射线荧光分析、X射线衍射分析、扫描电镜-能谱分析技术,首次系统地分析检测了来自北京、山西、甘肃等中国北方地区的27个古建油饰彩画中的绿色颜料。结果表明,其中15个样品使用了巴黎绿这种含铜、砷的人工合成颜料,其余样品未检测出矿物颜料,显色成分应为人工合成的有机物。在所有分析样品中未检测到古代常用的绿色颜料石绿和氯铜矿的存在。该研究工作开辟了光谱分析技术应用于古建油饰彩画颜料鉴定的新领域,为该类文物分析鉴定、修复材料的选择提供了科学数据。     

Monitoring the Air Influence on Cement–Lime Mortar Hydration Using Low-Field Nuclear Magnetic Resonance Relaxometry

In the present study, we investigate the relationship between the nuclear magnetic resonance relaxation rate and the hydration time in two types of masonry cement-lime mortar. The studies are performed with the mortars both in an enclosed and a standard atmosphere to monitor the air influence on cement-lime mortar hydration and setting. The constituents of the investigated mortar samples are: cement, slaked lime, sand and water. They were mixed to achieve a flow spread of 10?cm. These types of mortars are usually suitable for historical masonry maintenance, but they can also be used for modern buildings, or even for concrete structures coatings to prevent concrete carbonation. All nuclear magnetic resonance relaxation experiments were performed at 20?°C using a low-field nuclear magnetic resonance instrument operable at 20?MHz proton resonance frequency. A slowing down of the hydration kinetics is demonstrated for the samples kept in closed atmosphere conditions. The results contribute to the understanding of cement–lime mortar hydration, carbonation and setting under closed atmosphere conditions.     

Physico-chemical characterization of mortars as a tool in studying specific hydraulic components: application to the study of ancient Naxos aqueduct

Mortars and plasters from the ancient aqueduct on the island of Naxos, Greece, were studied with regard to mineralogical and chemical composition, grain size distribution, raw materials and hydraulic properties, in order to assess their characteristics and design compatible repair mortars. The authentic materials contained lime, crushed-brick, siliceous and calcitic aggregates, in different proportions according to mortar type. Crushed-bricks fired at low temperatures and lightweight volcanic aggregates contained amorphous phases, which upon reaction with lime yielded hydraulic components capable of protecting the construction from the continuous presence of water. Hydraulic calcium silicate/aluminate hydrates, the proportions and the perfect packing of the raw materials, along with the diligent application justify the longevity and durability of the studied samples. The hydraulic properties of samples were pointed out through (a) the well-established CO₂/H₂O ratio derived from the thermogravimetric analysis and (b) by introducing two powerful indices issued from the chemical analysis, namely CaO_hydr and soluble SiO_2 hydr. These indices improved the clustering of hydraulic mortars and provided better correlation between mortars, plasters and their binders. By comparing grain size distribution and hydraulicity indices it was possible to distinguish among the construction phases. Based on this study, repair mortars were formulated by hydraulic lime, siliceous sand, calcareous and crushed-brick aggregates, with the optimal water content, ensuring optimum workability and compatible appearance with the authentic ones.     

The application of electrical resistance measurements to water transport in lime–masonry systems

The paper describes an experimental determination of impedance spectroscopy derived resistance measurements to record water transport in lime–masonry systems. It strongly supports the use of Sharp Front theory and Boltzmann’s distribution law of statistical thermodynamics to corroborate the data obtained. A novel approach is presented for the application of impedance measurements to the water transport between freshly mixed mortars and clay brick substrates. Once placed, fresh mortar is dewatered by brick and during this time the volume fraction water content of the mortar is reduced. An equation is derived relating this change in water content to the bulk resistance of the mortar. Experimental measurements on hydraulic lime mortars placed in contact with brick prisms confirm the theoretical predictions. Further, the results indicate the time at which dewatering of a mortar bed of given depth is completed. The technique has then potential to be applied for in situ monitoring of dewatering as a means of giving insight into the associated changes in mechanical and chemical properties.     

Applied geology in analytical characterization of stone materials from historical building

Investigations of the provenance and technology of ancient materials are an important part of archaeological research. Studies of the geology of a region combined with petrographic research and chemical analysis may allow one to establish a possible source of raw-materials used. They also enable selection of the materials from currently accessible sources in the process of renovation or reconstruction of buildings [1–3]. Until now, the authors have carried out the studies in order to determine provenance of the raw-materials, the detailed analysis of composition (for the stone materials from Romanesque buildings in South Wielkopolska – Poland, and from ancient ruins in northern Israel and northern Egypt. Petrographic analysis (macro- and microscopic observations), cathodoluminescence (CL), X-raydiffraction (XRD) and stable isotopes analysis have been applied. In the next step, the detailed composition analysis enables, in the case of mortars, selection of suitable samples for dating [4, 9] and to determine the age of a given object, either directly by absolute dating (e.g. ¹⁴C of lime mortars) or indirectly, by relative age estimation on the basis of finds and artifacts (their components and characteristic style for a specific period). PACS 07.60 Pb; 78.60 Hk; 91.65 Dt; 91.60.-x; 07.85.Nc     

陶寺、殷墟白灰面的红外光谱研究

采用傅里叶变换红外光谱(FTIR)对天然石灰石、模拟白灰面以及采自陶寺遗址和殷墟遗址的白灰面进行了分析检测,以探明陶寺和殷墟遗址白灰面所用原料。结果显示,人工烧制石灰碳化后所形成的方解石,其ν₂/ν₄比值高达6.31,明显高于天然石灰石中的方解石,从而表明人工烧制石灰碳化所形成的方解石较之天然石灰石中的方解石具有较高的晶体无序度;随着研磨程度的增加,天然石灰石中的方解石和人工烧制石灰碳化形成的方解石,其ν₂和ν₄值逐渐减小,人工烧制石灰碳化形成方解石的ν₂-ν₄特征趋势线斜率较高,从而为考古出土人工烧制石灰的判定提供了一种简便、有效的方法。根据此判别方法,陶寺和殷墟遗址的白灰面很可能是采用人工烧制石灰所制备的,表明中国古代先民在距今4300多年的新石器时代晚期已掌握了石灰烧制技术。     

釉灰制备原料和工艺对其组成的影响

釉灰是我国古代独特的传统釉用核心原料,其中以景德镇生产的釉灰最具代表性和影响力,正所谓“无灰不成釉”。它不仅成就了景德镇宋元明清的制瓷盛况,而且拥有复杂、严谨且带有一丝“神秘”色彩的制备工艺,其原料选择、工艺原理、釉用机理长期以来一直是中外研究者探究我国古代制瓷“秘诀”的一个重要课题。实验采集了狼萁草等四种典型柴草和两种石灰石,分别进行了煅烧实验,并借助EDXRF和X射线衍射仪(XRD),对各原料灰化后的化学组成及不同煨烧次数所制得釉灰的化学组成和物相组成进行科学表征和对比研究,初步剖析了釉灰制备采用独特的三次煨烧工艺的科学意义。结果表明,狼萁草化学组成中Fe₂O₃和MnO含量分别高达1.41%和1.52%,而P₂O₅含量则为四者中最低的0.54% ,不仅有利于景德镇传统灰釉呈现 “白中泛青”的效果,还有利于提高釉层的透明度,促进景德镇传统釉下青花等彩绘瓷的发色。灰色石灰石不仅CaO含量低于黝黑色石灰石,且MgO含量更是高达35.79%,这正是古代制灰匠偏爱选择黝黑色石灰石的主要原因。此外,研究还发现,随着煨烧次数的增加,不仅釉灰化学组成中的K₂O,P₂O₅,MnO,Fe₂O₃的含量均呈明显递增趋势,且其物相组成中的CaCO₃含量呈递增趋势,而Ca(OH)₂含量则刚好相反,呈下降趋势,这不仅有利于景德镇瓷器呈现“颜如玉”的外观特质,也有利于克服配釉过程中釉浆因含一定量的Ca(OH)₂而引起的“作浓”现象。可见,釉灰制备选用独特的原料及其煨烧工艺,是景德镇古代灰釉独具特色并得以长期发展的技术保障之一。     

Protective performances of two anti-graffiti treatments towards sulfite and sulfate formation in SO2 polluted model environment

Specific strategies for protection are being developed to counter both the staining and corrosive effects of polluted air in cities, as well as to allow for efficient removal of unwanted graffiti paintings. These protection strategies employ molecules with tailored functionalities, e.g. being hydrophobic, while maintaining porosity for molecular water vapour permeation.The present study employs SO₂ and water to probe the behaviors of two anti-graffiti treatments, a water-base fluoroalkylsiloxane (“Protectosil Antigraffiti” marketed by Degussa) and an organically modified silicate (Ormosil) synthesized from a polymer chain (polydimethyl siloxane, PDMS) and two network forming alkoxides (Zr propoxide and methyl triethoxy silane, MTES) dissolved in n-propanol, on five building materials, comprising limestone, aged lime mortar, hydrated cement mortar, granite, and brick material.The materials were exposed to a synthetic atmosphere for 20 h in a climate chamber, 0.78 ± 0.03 ppm of SO₂ and 95% RH. Diffuse reflectance Fourier transform infrared (DR-FTIR) spectra were registered before and after exposure in the climate chamber in the cases of both treated and untreated samples. DR-FTIR, scanning electron microscope (SEM) images and energy dispersive X-ray (EDX) analyses, suggest the anti-graffiti Ormosil to suppress formation of calcium sulfite hemihydrate (the primary initial product of the reaction of calcium compounds with SO₂ and water) on carbonate materials (limestone and lime mortar).In case of the granite, brick and cement mortar, Ormosil has a negligible influence on the SO₂ capture. While no sulfite formation was detected by DR-FTIR, gypsum is inferred to form due to metal oxides and minority compounds catalysed oxidation of sulfite to sulfate. In case of brick, this understanding finds support from SEM images as well as EDX. A priori presence of gypsum in hydrated cement mortars prevents positive identification by SEM. However, support for sulfur accumulation in hydrated cement mortar is provided by means of EDX.In case of a second anti-graffiti considered, Protectosil, no influence of the anti-graffiti treatment on the SO₂ uptake of any of the building materials was observed.     

Study of ancient mortars from the Roman Villa of Pollio Felice in Sorrento (Naples)

The study of ancient mortars is an important aspect of building conservation: the choice of the materials has varied according to historical period, regional habits, and their specific function in the structure. Ancient mortars are composites, comprising hydraulic or aerial binding materials, and aggregates, passive or active, which may react with binding material. Moreover, they were modified during setting, hardening, and aging, according to processes not yet well known. In this paper, we present a study of ancient mortars from the Villa of Pollio Felice of Sorrento (Naples). The analysis has been performed by conventional techniques (grain-size distribution, lime-percentage analysis, optical and electron microscopy, and X-ray diffraction) and by means of a laboratory X-ray microdiffractometer equipped with an image plate detector. This system, applied for the first time to archaeological studies, can reach a spatial resolution of a few tenths of microns and it allows us to obtain separate phase identification of binder and filler particles. PACS 07.85.Nc; 61.10.Nz