The Research On Analysis And Reinforcement Measures Of Crack Of Reinforce Concrete Bridges

Our country’s major part construction of the service simple beam bridges were built from the beginning of the60’s to the end of the90’s. Bridge which constructed in this period of time was fouced on designment, the construction and over seeing gradually on consummate. These bridge shad various prominent problem after the construction and the operation10-20years, the flooring dehiscence, bridge plate the crack, abutment are vertically and horizontally damaged the settlement, the awlslope cave in, the bridge head jump off seriously and so on, nearly has covered the bridge complete structure.Nowadays the vehicles overload over speeds seriously has the very emerged. these questions gradually appear eriously has affected the vehicles security operation, has the enormous hidden danger. In particular center of the small bridge is the most prominent in the country provincial road and on the county town ship road, the majority of bridges are in3kind of bridges,even some4kind of bridges. Statistics have indicated, our country is opened to the traffic in the road network, up to2008year’s end, existing bridge278809, amounts to the length is10311794million meters,98.76%is the permanent bridge,0.67%is the semipermanent bridge,0.57%for temporary bridge. The smal1span bridge approximately composes the bridge total94.53%, but their middle majority is located the technical standard to be low, on the travelling capability difference county township road, the design load standard mostly for the steam-13, tows-60or the steam-15, hangs-80, also has quite Part of bridges load standards only is steam-10, the caterpillar band-50, even is lower than the automobile-10levels.As a result of the transportation enterprise development, the volume of traffic grows day by day, the vehicles carrying capacity remarkable enhancement, add sartificial or factor the and soon nature influence, has caused these bridges to beat one kind in spite of one’s illness, the excess load active status.The practice indicated that, concrete structure any damage and the destruction, generally all is first appears the crack in the concrete, the crack is reflects the concrete structure plant disease the barometer. Therefore, to the concrete structure damage diagnosis, first should from to the structure crack investigation, the examination and the analysis obtains.The reinforced concrete structural cracks origin complexly, even many kinds of factors mutual influence, but all of cracks have one kind of or several kinds of reasons. The reinforced concrete bridge beam crack type, it produces the reason which approximately may induce is two big kinds:First kind:crack causes which by the outside load, is called the constitutive crack (to be called stress crack), its distribution of the crack and the width concern with the outside load. This kind of crack appearances indicates the structure supporting capacity possible in sufficiency or has other serious problems.Second kind:crack causes which by the distortion, is called the non-constitutive crack, like factor and so on temperature change, concrete shrinkage causes when the structure distortion is restricted, can produce in the structure interior from the stress, when from the stress achieved when concrete tensile strength limit value, can cause the concrete crack.Once the crack appears, the distortion obtains the release, also vanished from the stress. Two kinds of cracks have the obvious difference, the harm effect are not the same.The investigation material indicated that, distorts the crack in two kinds of cracks which causes to occupy the leadership to approximately compose80%, the load causes the crack to occupy the leadership to be approximately compose20%. sometimes two kinds of cracks fuse in together which is the crack hazardous nature evaluates, crack patching and the einforcement basis to the crack reason analysis, if on blindly does not carry on processing to the crack after the analysis research, not only cannot achieve the anticipated effect, but also possibly is hiding the burst characteristics accident danger.In view of the center area bridge reinforcement application case, key for through for used the carbon fiber and glues the steel plate in forcemeats to carry on the analysis computation, because simple lank bridge highly smaller, relative reinforcement was bigger, uses which is eceiving pulls the area directly to additionally build makes up the strong material, still could not satisfy the design load the request, there fore simultaneous used the union flooring service quickly, took the effective structure measure, strengthened the flooring level and the center board whole connection,guaranteed the flooring level concrete participation king post affected together, reduces the reinforcement to make up the strong work load.