Experimental Study On The Mechanical Properties Of The Concrete Beam Reinforced By The Prefabricated Cage System Under The Action Of Pure Torque

Torsion components are widely used in the building structure. A lot of researcheson the torsion properties of the reinforced concrete structures have been done by thedomestic and foreign scholars, but the results showed that the torsion capacity wasnot ideal. Then a new type of concrete reinforcement system—Prefabricated CageSystem was proposed by Mohammad Shams coming from Russia Hai StateUniversity of the USA. Some studies have been done by Mohammad Shams andother foreign scholars, and the results showed that the concrete structure reinforcedby the Prefabricated Cage System has superiorities in terms of the compressionperformance, the construction process and the economic benefits than the reinforcedconcrete structure. In view of the well collaborative capabilities between theprefabricated cage system and the concrete, and almost none of researches have beendone on the torsion behavior of the concrete structure reinforced by the prefabricatedcage system, so it is of great significance to study the torsion behavior of the concretebeam reinforced by prefabricated cage system in state of pure torque.The article studied the torsion properties of rectangular cross section steel cageconcrete beam which was reversed by pure torque from two aspects: the experimentalstudy and the theoretical calculation. In the case of the limited test conditions of theschool, the author designed a set of test devices which almost met the force boundaryconditions to ensure that the research work could be proceed smoothly. First, six testbeams which were reversed by pure torque (including two ordinary reinforcedconcrete beams and four concrete beams reinforced by the prefabricated cage system)were experimental investigated, the article compared the pros and cons of concretebeams reinforced by the prefabricated cage system and the reinforced concrete beamsin failure modes, anti-crack performance, torsion bearing capacity. The effects of thevertical slats, the horizontal slats, as well as the opening way on the torsion capacityof the steel plate concrete beams were analyzed; Second, in the foundation of analysisthe calculation model and the calculation formula of the cracking torque and theultimate torque of the ordinary reinforced concrete beam, the article proposed the calculation formula of the cracking torque and the ultimate torque of the concretebeam reinforced by the prefabricated cage system which subjects to pure torsion.The experimental study showed that:(1) the prefabricated cage system and theconcrete of the beam has better anti-slip capabilities and collaborative capabilities;(2)the failure process of concrete beams reinforced by the prefabricated cage systemwhich were reversed pure torsion stress was broadly divided into four stages: thenon-crack stage, the stable development of the cracks stage, the rapidly developmentof the cracks stage, the bearing capacity falling stage;(3) the amount of reinforcingsteel had little influence on the cracking torque of the concrete beams reinforced bythe prefabricated cage system; and the formula of the cracking torque of thereinforced concrete beams also applied to the concrete beams reinforced by theprefabricated cage system;(4) the concrete beams reinforced by the prefabricatedcage system had greater ultimate bearing capacity of pure torsion than the ordinaryreinforced concrete beams with the same section size and reinforcement ratio (equalto the longitudinal reinforcement and stirrup reinforcement rate);(5) the openingmode (including the opening number and the opening size) and the processingaccuracy of the prefabricated cage system had large impacts on the torsion capacity ofconcrete beams reinforced by the prefabricated cage system.