Composite Modes And Experimental Study On Basic Performance Of GluBam-Concrete Composite Beams

GluBa m is the basic materia l o f modern bamboo structures, with broad prospectsof deve lopment in the fie ld of b uild ing structures and bridges structures,GluBa m-concrete composite beam came into be ing in these areas due to its goodmecha nical properties, workability a nd energy saving features. Compared withconventio nal re inforced concrete beam, the key characteristic of GluBa m-concretecompos ite beam is the replace ment of the lower part of the fragile re inforced tensileconcrete with GluBa m whic h has good tens ile capacity. As the research is still in theinitia l stage currently, the study of basic mechanica l properties of GluBa m-concretecompos ite beam, and the se lection of several appropriate connectors which can beused in GluBa m-concrete composite beams is of great theoretical significance andpractica l va lues. This artic le mainly worked on the pull-out test of GluBa m glued-inrods, designed several GluBa m-concrete composite beam connectors, testing theconnectors with s hear s lip tests, the ma in research contents are as follows:Firstly, with the pull-out test of GluBa m glued-in rods.A series o f tests had beenperformed, inc luded different adhesives, two ways of superpositio n methods and threedifferent depth of the pull-out performance. Test results ind icates that the uplift loadof liquid adhesive (A) is1.3times that of the slurry adhes ive (B); the fa ilure load oflateral o verlap specimen is1.17time that of the horizonta l overlap ones; the fa ilureload of the specimen is related to the imp lantatio n depth of the reinforced bars, inwhich the fa ilure load increased according to the depth increasing.On this basis, shear slip tests were conducted on concrete composite bea mswhich ha ve different connecting forms, in the tests we measured the bearing capa cityand relative slip of the compos ite beams were measured under different connectingmethods. The test results showed that the specime ns with continuous stee l mesh hasthe best bearing capacity and shear stiffness followed with the groove and boltconnecting form through all the specime ns with different connectio ns. When us ingthese two kinds of connecting methods, the load-relative slip curve has a strict linearelastic regio n and better plastic region, whic h is the most ideal one; w he n us ing boltand fo lded plate with sma ll shearing section as a connector, it tends to split theGluBa m and concrete slab; whether setting the waterproof layer has a great effect onthe composite beam, as the bearing capacity and the shear stiffness will dropremarkably when the waterproof la yer was set; the slot a ngle has little influence on it when us ing the groove type of s hear connector; nail the GluBa m could has littlecontribution to the growth of bearing capac ity, but can improve the anti-slide stiffnessremarkably; the specimen groove which has pretighte ning load couldn’t keep theconcrete and bolt working together, and the pretighte ning load could not be controlledaccurately in actua l operatio n, therefore the mecha nical properties of this type ofcompos ite style is decreased obvio us ly.The result of this stud y provide the GluBa m-concrete compos ite beam withimportant data in the design and calc ulation of the shearing connectio n, and lays thefoundatio n for the further research on this new comb ined structure.