Study On Reinforcement Mechanism Of Smart Prestressed Concrete Column Of SMA

Shape memory alloy is a kind of new functional material, it has the functions of shape memory effect and super elasticity. At present, in the field of civil engineering, shape memory alloy is little application in the aspect of structure reinforcement. This paper is based on the shape memory effect of shape memory alloy, and according to the basis of the tri-axial compression of concrete, that is the axial compressive strength increases with the increases of other biaxial stresses, we proposed a method which reinforced concrete cylindrical by SMA ring pre-stress, analyze the reinforcement mechanism of this reinforcement way, prove its reliability by experiment and calculation.In order to study the intelligent pre-stress reinforcement mechanism of shape memory alloy on concrete cylinders, First, physical properties of transformation temperature and tensile test on SMA have be done. In this paper, we carry out the axial compression tests of the plain concrete columns, the concrete cylindrical wrapped with no pre-stressed shape memory alloy and the concrete cylindrical wrapped with pre-stressed shape memory alloy, obtained the strain and normal use ultimate bearing capacity values of concrete columns in three states. The results show that, the compressive strength of concrete cylinder wrapped with pre-stressed shape memory alloy has been improved 36% obviously compared with the plain concrete columns and has been improved 14% obviously compared withno pre-stressed concrete columns, that is the crack resistance of concrete column has been improved obviously.We build the model of concrete column in three stats by using finite element software ANSYS, and get the normal use ultimate bearing capacity values by static analysis, then compare with the test results, the results is they are consistent, show that normal use ultimate bearing capacity values of concrete cylinder wrapped with pre-stressed shape memory alloy is improved 34% obviously compared with plain concrete column, that is its compressive strength is improved obviously.