The Expeirment Of Monolithic Reinforcement For Hollow Slab Of Reinforced Concrete

Reinforced concrete hollow slab girder bridge is the most widely used bridge typein the highway and urban road building in our country and it’s also a major bridge typewith small spans. The cracking of the hinge joint, the uneven load-carrying of thesupport and the longitudinal cracking in the slab bottom are three common “defects” ofthe reinforced concrete hollow slab girder bridge to which increasing attention are beingpaid. Therefore, to to find a simple and effective way to reinforce the reinforcedconcrete hollow slab girder bridge is of far-ranging practical use. Given the background,this papar provides two ways of reinforceing the reinforced concrete hollow slab girderbridge, which are horizontal pre-stress and addition of rigid beams. These two methodsare proved reliable and serving as a theoretical foundation of the reinforced concretehollow slab girder bridge.On the basis of mechanical theory analysis in hinge joints of hollow slab bridgewhich is made of reinforced concrete, the thesis summarized the failure mechanism ofhinge joints in hollow slab bridge by investigating common diseases andcharacteristics of hinge joints.We conceived strengthening scheme concludingtransverse prestress and building cross beam in addition; put forward layout principleof transverse prestress and the calculation methods of control on tentioning press;provided the designing calculation fashion and layout principle. All theconclusions were aiming at not interrupting the transportation and the diseasescharacteristics of hinge joints in girder bridge made of reinforced concrete hollow plate.In the meantime,we build up finite element models in correspondence to deal withnumerical computation through MIDAS FEA.And then analyze lateral distributionfeatures of deflection under each slab located in L/2section after reinforcement,results showed the validity of reinforced scheme proposed in this paper. Furthermore,it provides supports to analyze trials in hollow slab bridge models.Finally, by the experimental research of adopting transverse prestress, adding therigid beam and reinforcing method with both of them to reinforce the model, analyzecontrastively the load transverse distribution characteristic in the L/2section of hollowslab beams before and after reinforcement and get the effectiveness of differentstrengthening methods. Experimental results show that the load transverse distributionof hollow slab beams has different degrees of improvement after using three methods of strengthening them and the bearing capacity of the structure was improved. Bycomprehensive comparison, especially, the strengthening method of pasting andanchoring the rigid beam is the most obvious in improving the structure’s loadtransverse distribution and the method of reinforcement is more reasonable. The modeltest and numerical simulation verify that the integration strengthening of the reinforcedconcrete hollow slab has good reinforcement effect.The integration strengthening combining transverse prestress with adding the rigidbeam for the reinforced concrete hollow slab bridge proposed by this paper has theadvantages of convenience and no traffic interruption and has the broad market prospectand application value, which will produce great economic and social benefits.