Research On Super High-early-strength Concrete Suitable For Segment-continuous-precast Bridge Slab

Based on the construction project of science and technology of the Ministry of Transportation "Research of the Basic Theory on the Construction of Super Large Span Steel Truss-Concrete Composite Continuous Rigid Frame Bridge"(No.2013319814040),our research group put forward the conception “The precast continuous segment and steel concrete composite beam bridge post incremental launching method and the fast construction”[1],this article explores the preparation and maintenance conditions of segmented-continuous-prefabricated bridge slab concrete.The main research contents are as follows:1、Aimed at the concept of “The precast continuous segment and steel concrete composite beam bridge post incremental launching method and the fast construction”put forward by the tutor,the technical requirements for preparation and maintenance of concrete materials for factory construction of segmented-continuous-prefabricated bridge slab were discussed in this paper.2 、 The Mix Design of Super High-Early-Strength Plain Concrete and Super High-Early-Strength Steel Fiber Concrete were discussed in this paper.In addition,by using the preparation of super early strength agent as the main parameter to carry out experimental research,the suitable mix proportion of super early strength concrete was put forward.Meanwhile,through testing to determine the suitable steel fiber content in steel fiber reinforced concrete and the best ratio of super-strength agent,Super High-Early-Strength Steel Fiber Concrete was prepared in this paper also.3 、 By using the maturity of concrete as the main technical parameter,the mechanical properties of concrete at different temperatures and curing times were studied.And based on literature data,the relationship between the maturity and strength of concrete under normal temperature conservation was studied.Meanwhile,according to the statistical analysis of test data,the correspondence between concrete strength and maturity under high temperature curing was proposed.4、The effects of different heating rates and cooling rates on the concrete structure during high temperature curing were studied in the paper.Meanwhile,the internal cell structure of the concrete at different heating rates and cooling rates was observed with an electron microscope,and the mechanical strength of the concrete was compared,then the appropriate heating rate and cooling rate under high temperature curing were proposed.