Research on the building materials of adobe house in the Neolithic period at the Qingtai site, China

Abstract

AbstractAs one of the earthwork building methods, the adobe masonry has a long history around the world. In 2015, the Zhengzhou Institute of Cultural Relics and Archaeology discovered the earliest adobe house in Prehistoric China at the Qingtai Site. In this work, physical properties, material composition, and microstructure of the adobe brick and other earth samples gathered in this adobe house were studied. The results showed that the density and surface hardness of the adobe brick reached 2.12 g/cm and 91 HA, which was second only to the rammed house floor sample. The adobe brick contained about 13.2% of plant fiber, and in its inorganic composition, the clay cement with particle size less than 0.075 mm accounted for 90%. The results of XRD analysis showed that the content of kaolinite in adobe brick was 2–5 times that of other samples. The structure analysis displayed that the adobe brick was much more compact, and its porosity was about 28.6%. These research results demonstrated that the adobe brick was formed under a certain pressure and its raw materials were different from those of other samples in this adobe house.