Research On Box Girder Curing Process Of Large Span Prestressed Continuous Rigid Frame Birdge Of The Cantilever Construction Segments

The large span prestressed concrete continuous rigid frame bridges are widely usedin the construction of mountain highway by the advantages of the big span、the easyconserve and the concretion of pier and beam.But because continuous rigid frame boxgirder cantilever segmental casting on high pier and the working face restrictions afterdemoulding box girder in vitro on the surface of concrete is difficult to maintenancereasonablely,besides,the influence of the wind valley will lead a bridge after the cabinetbottom bottom existing a large number of longitudinal cracks and the cracks in thelateral horizontal more than the inside,which will lead to a serious threat of structuredurability. This causes the extensive concern of the engineering gradually. For boxgirder roof and the curing of concrete can use in the traditional maintenance method, butfor the outside of the bottom plate and web plate curing is not applicable. The shrinkageof concrete are mainly concentrated in the early days, and intensity is low, so strengthenthe early curing box girder plate and web plate is an important link of concrete crackcontrol.This paper combines with the chongqing traffic science and technologyproject——《Long-span prestressed concrete continuous rigid frame bridge in cantileverconstruction process of segment curing process research》,obtains the hydration heatdata base on the experiment,contraposes the shatangba bridge of concrete structure oftemperature field calculation by midas ciliv software. The purpose is to seek the mostsuitable for mountainous area prestressed continuous rigid frame bridge in cantileverconstruction of box girder web plate lateral plate curing method. The main workaccomplished in this paper:①Through access relevant information, review research status of bridgemaintenance at home and the abroad.And demonstrates the long-span prestressedconcrete continuous rigid frame bridge in cantilever segmental constructionmaintenance necessity and overall thinking.②Start from the choice of materials during the construction and analyse theinfluence of cement fineness and composition of the concrete hydration heattemperature drying shrinkage creep strength, etc.③The hydration heat of data obtained through experiments, the box girderconcrete structure temperature field computing research, comparative analysis of theearly concrete box girder temperature field under different curing methods. ④Analysis of automatic water spray mist spraying curing agent curing membranecuring the adaptability of the early concrete curing method and its technical andeconomic rationality.⑤Based on the projec the automatic spray system has achieved good benefits,therefore, in order to promote the text the method of construction was prepared.