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What problems have concrete encountered in history and development?
Concrete was used in the ancient west. The Romans used natural concrete made of volcanic ash mixed with lime and sand in some ancient buildings. Natural concrete has the characteristics of strong coagulation, durability and impermeability, which makes it widely used in Rome, greatly promotes the development of Roman architectural structure, and constantly makes breakthroughs in the span of arches and domes, creating a large number of existing public buildings that are still talked about by people. In BC 1 century, natural buildings almost completely rejected the stones in the arch structure.

Portland cement appeared from 19 in the 1920s, and was widely used because of its good strength and durability, easily available raw materials, low cost, especially low energy consumption (see inorganic cementing materials).

At the beginning of the 20th century, the theory of water-cement ratio initially laid the theoretical foundation of concrete strength. Later, lightweight aggregate concrete, aerated concrete and other concrete appeared one after another, and various concrete additives began to be used.

Since the 1960s, water-reducing agents have been widely used, and high-efficiency water-reducing agents and corresponding fluid concrete have appeared. Polymer materials entered the field of concrete materials, and polymer concrete appeared; A variety of fibers are used to disperse reinforced fiber concrete. Modern testing technology is also increasingly applied to the research of concrete material science.