Numerical Study Of Meso-structure About Concrete Column Wrapped With Tube Of Different Form

Compared with concrete under uniaxial compression loading condition, Concrete under triaxial compression loading condition can obviously improve bearing capacity. Therefore, tube made of different material can be filled with concrete to work as column. For example, steel tube filled with concrete have been widely used and called steel concrete filled tubular column. At present, most studies of the concrete filled tubular column are based on experiment.Concrete filled tubular column restrain the development of the interior tiny crack and improve bearing capacity by the restriction of the tube. Research of the meso-mechanics of the concrete filled tubular column can help us study the failure of this kind of column profoundly.In this paper, we study the meso-mechanics of the concrete filled tubular column including tubes of variable form by three-dimensional meso-structure numerical simulation method wich take the concrete as a type of three-phase composite material composed of mortar matrix , aggregates and bonds connecting the matrix and aggregates. The numerical simulation models are randomly generated with Monte Carlo method and consider the nonlinear constitutive relation of the materials. Concrete filled tubular columns including tubes of variable form in this paper are divided into 3 groups. In group 1, there are PE, HDPE, PVC, steel concrete filled tubular columns; In group2, there are PE, HDPE, PVC, steel concrete filled tubular columns wrapped with a layer of GFRP; In groups3, there are PVC concrete filled tubular columns wrapped with multilayer GFRP.By the results, we try to discuss the relationship between the failure of the concrete column wrapped with different form and the meso-mechanics of the different interior material(mortar matrix , aggregates and bonds connecting the matrix and aggregates).