Experimental study on mechanical performance of precast composite primary and secondary beam joints connected by steel groove
In order to study mechanical performance of precast composite primary and secondary beam joints connected by steel groove,a precast composite primary and secondary beam joint specimen connected by steel groove and a cast-in-place primary and secondary beam joint specimen were designed.Static loading tests were conducted to investigate the failure mode,bearing capacity,deformation capacity,load-cantilever end deflection relationship,steel bar strain and steel groove stud strain,etc.The research results indicate that the cracks of precast composite secondary beam connected by steel groove are mainly concentrated in the interface between the primary and secondary beam,within the range from the fixed end of secondary beam to the steel groove,and the bottom of the secondary beam,which is manifested as the bending failure of the fixed end of secondary beam.The cracking load and yield load of precast composite secondary beam connected by steel groove can be basically equivalent to the cast-in-place beam,and the flexural bearing capacity of normal section is about 10.0%higher than that of cast-in-place beam.When the load at beam end is less than 80kN,the proximal studs of the steel groove are compressed,while the distal studs are pulled.When the load at beam end is greater than 80kN,the stress of each studs of the steel groove increases sharply.The ratio of the measured value of the flexural capacity of the normal section of the precast composite secondary beam connected by the steel groove to the calculated value of the Code for design of concrete structures(GB 50010-2010)(2015 Edition)is 1.09.The flexural bearing capacity of the normal section can be predicted according to the calculated value of the specification.The strut-and-tie model calculates that the failure mode of prefabricated composite secondary beam connected by steel groove is failure of the tension bar(flexural failure).
steel grooveprecast composite primary and secondary beammechanical performancestatic loading teststrut-and-tie model
NETL
NSTL
万方数据
