Research On Ring Driving Of Shape Memory Alloy In The Concrete

According to the principle of axial compressive strength of concrete increases with the increase of other biaxial stresses, and on the basis of the shape memory effect, a new kind of structure-concrete ring driving structure was researched in this paper, i.e. SMA smart concrete. And a new way of pre-stressed - ring pre-stress was put forward,which can make the structure reach the ideal working condition of triaxial compression before being damaged. It is also pointed out in the paper that some problems should be solved before the ring pre-stress concrete structure of shape memory alloy is popularized and applied, as well as the research direction concerned.This text, in order to study the ring pre-stress concrete structure of shape memory alloy, on the basis of theoretical analysis, by studying the domestic and international relevant SMA documents and materials, various kinds of characteristics about SMA, project meaning and domestic and international research present status of SMA have been known. We had a shape memory effect of phase transition point, recovery stress and the determination of the size, then we compare to cold drawn and drawing of alloy. After heating the concrete structure at 100℃, we conducted study of axial compression, which the concrete columns, no pre-strain and pre-strain alloy wire concrete columns. By analyzing and testing, the law of the bearing capacity variation and the deformation of the concrete column have been obtained in 3 kinds of condition, SMA having pre-strain, having no pre-stain and having no ring to restrain.The load-strain curves of three different kinds of concrete structure have been analyzed by testing the compressive strength of the concrete samples. It is shown that the ring driving of the shape memory alloy in the concrete can not only restrain the cracking, but also enhance the compressive strength of concrete indirectly, which is basically consistent with the theoretical analysis.