Study On Compressive Mechanical Properties Of FRP Steel Reinforced Concrete Composite Columns

FRP steel reinforced concrete composite structure is a new type of fiber,steel bone and concrete composite structure.Compared with the traditional reinforced concrete,the self-weight of the structure is smaller,and the section size is smaller,the span and the toughness are higher than those of the traditional reinforced concrete in the same bearing range.Compared with steel structure,this new composite structure can obtain higher structural stiffness and stability under the condition of small steel content,and improve the integrity of the structure at the same time.Due to the existence of FRP material,the new composite structure not only has good external transverse constraints to ensure the bearing capacity of the structure,but also can be used as a good protective layer to improve the composite structure.Durability and structural fire resistance.In this paper,GFRP and CFRP steel reinforced concrete composite structures are described respectively,and the main contents of the study are as follows:In order to study the mechanical properties of GFRP steel reinforced concrete composite columns under different compression conditions,the theoretical research and finite element analysis of 5 composite columns subjected to axial compression and 8 composite columns subjected to eccentric compression are carried out in this paper.At the same time,the calculation formula of bearing capacity of composite columns is deduced.Through the finite element analysis of the composite column,the influence parameters of the composite column under axial compression and eccentric compression are analyzed,and the stress-strain relationship curves of the composite column at different stress stages are analyzed.For the eccentric compression member,the lateral deflection of the composite column in the stress process is analyzed.In order to study the mechanical properties of CFRP steel reinforced concrete composite columns during compression,the finite element simulation of 12 composite columns is carried out in this paper,and the improvement of bearing capacity of composite columns under different outsourcing conditions is more intuitively analyzed,so as to reduce the waste of resources in the manufacture of composite columns.At the same time,the effect of freeze-thaw conditions on the mechanical properties of the composite column is studied,and the area reduction of concrete during freeze-thaw process,the stress concentration caused by corrosion of section steel during freeze-thaw process and the damage of CFRP cloth in freeze-thaw process are studied respectively.the section steel and mixing are given by theoretical derivation.At the same time,the calculation formula of bearing capacity of composite columns after freeze-thaw is determined,and the calculated results are more close to the engineering practice.