Study on mechanical properties of fully assembled composite beams with bond-tooth glued joint bridge decks in negative moment region
Under the most unfavorable loading conditions in the negative moment region of a typical continuous beam,this study investigates the mechanical performance differences between an integral bridge deck and a key-tooth glued joint bridge deck.To analyze the load-bearing behavior and flexural capacity of key-tooth glued joint composite beams under various influencing factors,an expression for flexural capacity is proposed that incorporates the steel beam,epoxy resin adhesive,prestressed rein-forcement,and key-tooth geometry.To validate this expression,two steel-concrete composite beams with detachable high-strength bolt shear keys and bridge decks are designed and fabricated,including one with an integral bridge deck(N1 composite beam)and one with a segmental precast key-tooth glued joint bridge deck(N2 composite beam).Static load tests are conducted on a test platform,and fi-nite element modeling is performed in Abaqus to study the crack development,load-displacement and load-strain relationships,and failure modes of both composite beams.Results indicate that,in the post-failure loading phase,the N1 composite beam exhibits bending failure,while the N2 composite beam shows bending-shear failure,with respective bearing capacities of 675 kN and 605 kN.The ulti-mate bearing capacity of the N2 composite beam in the negative moment region decreases by approxi-mately 11%.The N1 composite beam demonstrates a curvature of 20.5,ductility deflection coefficient of 5.57,and section curvature of 42.46×10-6,while the N2 composite beam has a curvature of 30.7,ductility deflection coefficient of 6.20,and section curvature of 98.42×10-6,showing an approximate 10%increase in ductility and a 130%increase in rotational capacity compared to the N1 composite beam.The cracking load of the N1 composite beam is 33%lower than that of the N2 composite beam,with cracks in the N1 beam distributed widely,closely spaced,and numerous,whereas the N2 beam has cracks concentrated near the key teeth,with wider spacing and fewer occurrences.Compar-ing the calculated values of the proposed flexural capacity expression with test and finite element val-ues,differences are found to be within 5%,demonstrating the expression's feasibility.
steel-concrete composite beambearing capacityglued jointkey-toothfinite element modeling analysis
万方数据
维普
