Study On The Properties Of Reinforced Recycled Aggregate Concrete Column With Central Spiral Stirrups Core Column

In order to improve the bearing capacity and seismic behavior of concrete column, the general method is increasing the section size of column or using composite structures like steel reinforced concrete and concrete filled steel tube in structural elements. Increasing the section size of column not only increased the weight of structure, but limited the use of architectural space. Steel reinforced concrete and concrete filled steel tube have a series of problems such as lager steel consumption, poor fire-resistant, complicated joint connection and construction. Reinforced recycled aggregate concrete column with central spiral stirrups core column set spiral stirrups in the center of reinforced recycled aggregate concrete columns. This kind of column can improve the load-bearing capacity and ductility performance while saving natural resource and making waste concrete recycling due to the combination of recycled concrete. That is an effective way to realize green and high performance requirements of structural elements. Through experimental study and calculating analysis, this paper researched the basic mechanics performance of reinforced recycled aggregate concrete column with central spiral stirrups core column for providing certain theoretical references for its popularization and application.Through axial compression test and eccentric compression test on twelve reinforced recycled aggregate concrete column with central spiral stirrups core column, expounded the main experimental phenomenon and failure mode. Detailed researched and analyzed the bearing capacity, load-strain curves, load-displacement curves, load-deflection curves of each specimen and discussed the working mechanism of spiral stirrups core column. The test results show as follows.(1) Recycled aggregate can formulate C60 high strength concrete that conform to the specification requirements. Properties of test specimen perform well.(2) The results of reinforced recycled aggregate concrete column with central spiral stirrups core column axial compression test and secondary loading test show that the central spiral stirrups core column concrete can still bearing load in spite of the peripheral concrete has been destroyed and destructed columns are still have a certain bearing capacity. Seismic and collapse resistant capacity of columns can be improved effectively by the central spiral stirrups reinforcement.(3) Contrast with recycled steel reinforced concrete filled with steel tube columns and combine with working mechanism, confinement effect of spiral stirrup act on concrete is inferior to steel tube. Confinement effect conduct by steel tube is much better. But in respect of the assurance of columns bearing and deformation capacity after column destroyed, spiral stirrups core column perform very well.(4) Contrast with the bearing capacity calculation value of general eccentric compression columns, reinforced recycled aggregate concrete column with central spiral stirrups core column eccentric compression bearing capacity has been greatly increased. The percentage of bearing capacity improvement is generally higher than 50% and the highest is 80%. In addition, eccentricity is the main affecting factors that impact bearing and deformation capacity of eccentric compression columns.