Hollow Centrifugal Concrete Filled Steel Tubular Members in Industrial Structure Application

Centrifugal concrete has been quickly developed in prefabricated concrete members, since it was invented by W.R.Hume in 1915. It was reported that hollow centrifugal concrete (HCC in short) filled steel tubular pile was developed in Japan in 1972. In 1994, it was manufactured in Shanghai China. Recently over 6,000 HCC filled steel tubular piles (400,000m in total) have been installed successfully for industry equipment foundation in Shanghai, and it also can be used as frame members in industrial structures. HCC filled steel tubular members can be manufactured in plant and can be transported and installed like other prefabricated steel and concrete members. They have the advantages of cost saving and internal resistance to corrosion. HCC filled square steel tubular members are developed which joints and connections are more convenient than that of HCC filled circular steel tubular members. Load capacity in compression and bending of HCC filled steel tubular member is studied by theoretical analysis and experiments. It is proved that load capacity in compression is influenced by the strength and section area of concrete as well as steel, constraining coefficient, concrete hollow coefficient. As the filled HCC is of C80 strength grade, in order to decrease the thickness of steel tube and improve the constraining coefficient, HCC filled high strength steel tubular member is developed in industrial structure application. In this paper, two important problems of HCC filled steel tubular member used as pile are discussed. The first problem is the reliability degree of axial load capacity, the other is dynamic interaction between HCC and steel tube caused by pile driving pulse and bond strength.