Study On The Axial Compression Behavior Of Reinforced Concrete Circular Short Columns Strengthened By Outsourcing CFRP And UHPC

Carbon fiber cloth(CFRP)and ultra-high performance concrete(UHPC)have superior mechanical properties,and gradually developed into a very promising building material in the civil engineering construction industry.If the combination of the two will complement each other,it is expected to form a new type of concrete structure with good mechanical properties and applied to practical engineering.CFRP is composed of high tensile carbon fiber bundles,which is lightweight and high-strength.UHPC is the researcher using the maximum density accumulation theory,by determining the effective particle size of the different particle sizes of the constituent materials,the ultra-high performance cement-based engineering materials are developed to produce tight packing with better specific gravity,the emergence of UHPC breaks the cement-based material material function and use of the scope of the scope of action,with ultra-high compressive functional strength,ultra-high stability and other characteristics,at the same time has good wear resistance,corrosion resistance and other good properties.With the rapid development of infrastructure projects in China,the requirements for concrete are getting higher and higher,so the application prospects of CFRP combined UHPC reinforcement will be very impressive.However,at present,CFRP wrapping methods need to be further studied,so different wrapping methods of CFRP are studied and compared to find a better wrapping method to better play the effect of CFRP constraints.In this thesis,the axial compression test of CFRP constrained column was carried out to study the influence of CFRP on the axial compressive performance of UHPC reinforced column in different forms.Using YAW-5000 KN servo pressure testing machine to carry out axial pressure test at room temperature,the results show that CFRP and UHPC reinforcement to improve the bearing capacity is large,CFRP ring-wrapped UHPC reinforced column has the best effect of improving bearing capacity and ductility,CFRP all-inclusive UHPC reinforcement column effect is second,followed by CFRP internal outsourcing.Through the empirical formula specified in the specification and the research results of predecessors,the theoretical calculation of CFRP-constrained UHPC reinforcement short column is carried out.On the basis of previous research,the CFRP-constrained UHPC reinforcement Column considers the radial confinement effect of CFRP on the inner and outer sides,and refers to the material utilization coefficient,and equivalents the CFRP structure on the inner and outer sides as a one-layer structure,and the calculated value is in good agreement with the experimental value.In order to verify the accuracy of the theoretical calculation method,finite element analysis simulation and theoretical operation of bearing capacity were carried out for three different CFRP-constrained UHPC reinforcement columns,and the theoretical operation results were in good agreement with the test experimental results and the simulation simulation results.The research content of this thesis provides a reference for CFRP to improve the confinement effect of concrete in the core area,overcomes the shortcomings of existing reinforced concrete columns,and provides a research basis for the practical application of CFRP constraining columns in different ways,which has good use prospects and research value.