摘要
During 1970s, the residential remains of the Yangshao Period were discovered at the Dadiwan site in Qin＇an County, Gansu Province, China. With carbon-14 dating, scanning electron microscope （SEM）, thermal expansion analyzer, polarizing microscope （PLM）, and X ray diffraction （XRD）, the microstructures and chemical compositions of the pottery shard, floor materials of the housing site, kunkur, calcined kunkur, ginger nut （calcium concretion） from the Dadiwan site were analyzed and re- searched. Analysis and simulation tests were also carried out to study the hydratability of calcined ginger nut and calcined kunkur, and the manufacturing process of the residential floors. The research shows that the floor was made of a light concrete formed by the mixture of aggregate of calcinated ginger nut （locally deposited）, red clay and kunkur. The dicalcium silicate （C2S） from the floor material of the housing site is one of the main constituents of modem cement, and the floor is also similar to modem concrete in nature. Therefore, the floor material of the housing site at the Dadiwan site was the earliest man-made concrete in the world ever discovered.
