Research On The Mechanical Behavior Of Expansive Concrete-filled Steel Tube With Large Diameter Tower Column

Concrete filled steel tube structure has been widely used because the characteristics of good mechanical performance and construction simple. Commonly found in industrial plants, high-rise buildings, large-span arched bridges, fewer applications in suspension bridge. Application of the concrete filled steel tube on the suspension bridge tower is an innovation. Tower section is usually larger, for large size steel tube concrete tower, because of the shrinkage and creep of concrete and other factors, will cause the defects of the concrete and the steel tube wall cavity causing confining stress appears too late. Using expansive cement or adding expansive agent, concrete generated in the process of condensation sclerosis ettringite in under the action of expansion can be packed into wool stoma, cement stone structure is more compact, material mechanics performance has been improved to a certain. For large diameter steel tube from stress and bearing capacity of expansive concrete condition of study is less, this article main researches can be summarized as follows:(1)According to the outer diameter1500mm, wall thickness50mm of four groups of specimens filled with C40expansive concrete, expansive agent content is10%,12%respectively. Through the acquisition of steel tube surface and core concrete strain and temperature change. Adopt cylinder under internal pressure and temperature of the lame formula and the formula of strain energy. Steel pipe are analyzed and calculated by stress and self-stressing concrete, determines the construction of the bridge tower of expansion agent content.3000mm outside diameter of the bridge tower construction segment were monitored to obtain expansive content of10%strain and temperature parameters.(2)Using ABAQUS software, the temperature of concrete constitutive model is used for heating expansion simulation. Heating value of the core concrete needs through software trial to determine the pipe to reach the same test to make stress-strain values. By temperature loading, get the stress distribution and core concrete pipe.(3)Design the diameter of0.8m,0.8m,1.2m,2m,2.4m five group of concrete filled steel tube long column, a total of40artifacts, by raising the temperature of ABAQUS0℃,10℃,20℃and40℃extraction operation load and deformation as a result, by considering the expansion under the action of each component bearing capacity and deformation curve, compared the different expansion effect of bearing capacity.(4)ABAQUS software is adopted to establish the model of the bridge tower.In accordance with the relevant experimental results carried out on the pillar in the concrete equivalent to heat up inflation. On the basis of bridge tower related design load parameters to the upper load. Running components get the stress distribution and deformation condition, the results meet the design requirements...