明清临清贡砖生产及其社会影响

明清两代修建北京皇宫各大殿和紫禁城城墙,以及皇家陵寝所用大青砖,绝大部分是山东临清州烧造。从明初到清末的四五百年中,临清因京杭大运河的贯通而成为北方重要的工商业城市和漕运咽喉,又因其便利的交通和适宜的土质等特殊优势成为明清两朝的贡砖烧造基地。临清的贡砖生产虽间有停废,但一直受到朝廷的严格掌控,形成了一套系统的管理制度和生产方式。大规模的贡砖烧造一方面促进了临清工商业的繁荣和生产结构的改变,同时也加重了民众和漕运官军负担,对明清时期的临清社会带来了巨大的影响。     

The Making of Fired Clay Bricks in China Some 5000 Years Ago

Fired bricks are a hard and durable masonry material that has played a major role in the emergence of early human urban civilization. In China, fired clay bricks have been widely used as a building and flooring material since the Qin Dynasty (476?206 bc ), although a few lines of evidence show that fired clay bricks might have been invented as early as 5500 years ago in eastern central China. However, these burnt clumps of clay appear not to be bricks in the strict sense, and our knowledge about the origin of fired clay bricks in China still remains fragmentary. Archaeological excavations at a Middle Neolithic cultural site in northwestern China reveal that the making of fired clay bricks began some 5000 years ago. Our findings also open a window into the process of prehistoric brickmaking in East Asia.     

Field Methods for the Analysis of Mud Brick Architecture

Recent research into mud brick architecture have established that the simple mud brick is a potential source of cultural information and can provide information about chronology, technology, identity, labor, resources, and environmental conditions. Some analytical techniques for the analysis of sun-dried mud bricks are dependent on the exportation of archaeological samples to foreign laboratories. Some countries severely restrict (or prohibit) the export or removal of archaeological materials making it essential to conduct analysis while in the field. This paper demonstrates the successful use of in-field procedures using a range of portable equipment to quantify basic mud brick characteristics, including particle size distribution through wet sieving, RGB color, magnetic susceptibility, and acid digestion to quantify calcium carbonate. Field and laboratory methods were compared on a single data set, specifically the assemblage from the Neolithic Anatolian site of Çatalhöyük. The results confirmed the accuracy of these methods and provide effective field techniques for mud brick analysis. This article provides an overview of recent research highlighting the importance of mud brick studies and provides procedures for in-field analysis of materials.     

Mineralogical and Mechanical Properties of Masonry and Mortars of the Lucknow Monuments Circa the 18th Century

The Lucknow monuments of the 18th century are large masonry structures built using thin burnt-clay bricks (Lakhauri) and lime-crushed brick aggregate (surkhi) mortars. Investigations were carried out to characterize the engineering properties of old masonry materials and new mortars being used for renovation work. Mechanical properties of reclaimed Lakhauri bricks were found comparable to good quality contemporary bricks of the region. Moreover, X-ray diffraction (XRD) and scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS) analyses indicated that mineralogical composition is not too different, except for few minerals. The lime-surkhi mortar used in old masonry work was found to be lime-rich with binder to aggregate ratio of approximately 1:2 to 3 by volume. The renovation mortar had poor hydraulic property as compared to old mortars indicated by thermal gravimetric analysis–differential thermal analysis (TGA-DTA) analyses. The compressive behavior of multi-wythe recreated Lakhauri masonry prisms was characterized with low compressive strength, low modulus, and significant deformability which result in lower stress demands imposed on the structural assemblages by various environmental forces.