Experimental Study On Pull-out Capacity Of Rebar Anchored In Embedded Corrugated Sleeve In The Concrete-filled Steel Tubular

In recent years,with the rapid growth o f China’s econo my,the construct ion industry is also boo ming.The tradit ional cast-in-place system,which emerged in the1980s,has made remarkable contributions to China’s urban and rural construct ion,but it also has many problems,such as environmental po llut ion,serious material loss and co mmo n construct ion qualit y problems.Under this background,the construct io n industrializat ion led by pre fabricated building is gradually promoted and becomes prevailing trend o f future construct ion industry.At present,reinforced concrete structure system and light steel system are most widely used in building industry,while introducing concrete-filled steel tube composite structure system into the field of prefabricated building can give full play to the advantages of excellent mechanical propert ies,plasticit y and toughness,and simple construct ion techno logy o f concrete-filled steel tubular structure.Therefore,this paper puts forward a kind o f connect ion mode,embedded metal corrugated sleeve with high strength grout ing material after rebar inserted,which is to be applied to the concrete-filled steel tubular co lumn to steel beam or co lumn to co lumn,for the purpose o f realizing the prefabricated assembly connect ion of the c oncrete-filled steel tubular co lumn,and carries out experimental research and result analysis on the mechanical propert ies o f this t ype o f jo int.The research content of this paper mainly includes the fo llowing aspects:(1)A research focusing on the anchoring performance o f rebar anchored in embedded corrugated sleeve in CFST is conducted in this paper.The pull out test was carried out with 48 fastenings,considering metal corrugated sleeve diameter D,rebar diameter d,anchorage length l_a and space c between rebar axis and the outer wall o f steel tube on the anchorage performance,in order to verify the reliabilit y o f this connect ion.(2)Pull-out test rebar anchoring length calculated values according to the standard in China,America,and European are co mpared wit h the actual anchor length,which is required by the steel yield strength and tensile strength in this paper,suggest ions are given for the anchorage length o f the rebar inserted in CFST embedded metal corrugated sleeve.(3)Co mparison and analysis of tests in this paper and pull out tests of plain concrete corrugated sleeve grout ing anchor bar was carried out,including failure mode,F-s curve,yield load and ult imate load,According to the plastic hinge line theory,this paper establish a simple mechanical model o f deformed steel cube in order to determine the failure mechanism o f the CFST specimens in the process o f pull out test and the influence o f steel cubes on the CFST rebar anchorage in embedded corrugated sleeve.