The Structural Potential Of Self-stressing Concrete In The Continuous Bridge Deck Pavement

Bridge deck pavement is the protective co ating of bridge structural system. And as a forced layer at the s ame time, the deck pave ment is directly impacted by the external loads and other natu ral environment factors. Quality and health of the bridge deck pavement directly affect the comfortable degr ee of road and the durability of the bridge structure. For the S teel Fiber Reinforced Self-stressing Concrete(SFRSSC), th e expansion of self-stressing concrete is restricted by steel fibers from all directions, w hich produces a certain pre-compressed stress. Concrete matrix becomes more densified. The crack resistance and du rability have been gr eatly improved. It is an ideal m aterial for bridge deck. Meanwhile, when the Steel Fiber Reinforced Self-stressing Concrete is used as bridge deck pavem ent, the inside self-s tress has a favorable im pact on the bridge structural system and this part of structur al potential cannot been ignored in the bridge structural design and construction process. Based on this issue, relying on the National Natural Science Foundation of China(41430642), the National Natural Science Foundation of Y outh Foundation of China(51108207), China Pos tdoctoral Science Foundation(2015M581403) and the State Key Laboratory of Frozen Soil Engineering Foundation(SKLFSE201514), the following researches have been down:(1) The single-span composite T-shaped beams test is taken to simulate and analysis the influence of SFRSSC deck pavement on the flexural properties of bridge system. The crack resistance of composite beam s is subs tantial increased. The growth rate a nd the extending height of cracks is inhibited.(2) Nonlinear numerical analysis is taken for the single-sp an composite T-shaped beams test by finite element analysis software. The influence of different pre-compressed stress on the flexural propertie s of tes t beams is research ed. A reasonable values of pre-compressed stress is obtained as 1.5Mpa ~ 2.5Mpa.(3) By two-span continuous composite T-shaped beam test, the working performance of the bridge structure with SFRSSC deck pavement is investigate. The result shows that the SFRSSC laminated layer obviously increased the cracking load of the test beam but has no impact on the cracking load and yielding load of the mid-span section. At the same time, during the loading process, the SFRSSC laminated layer delayed the appearance of cracks and restrained the development of cracks.(4) The simulation analysis for two-span continuous composite T-shaped beams is taken to study the af fection of length of SFRSSC la minated layer on the bending performance of test beam s. the reasonable length of SFRSSC la minated layer(the L shown in Fig.6.10) is 1/3~1/2 of the beam span.(5) The th eoretical analysis of single- span composite T-shaped beams build a calculation model for the cracking load. Th e theoretical cracki ng load is in good agreement with the experimental and simulation values.(6) A continuous bridge model with SFRSSC deck pavement is established to explore its working performance. The resu lts showed that steel fib er reinforced self-stressing concrete is a is the idea l material for bridge deck pavement. The inside pre-com pressed stress can reduce the negative moment at the middle support caused by loads and weight. The SFRSSC deck pavement can also suppress the development of the concrete cracking at the m iddle support. Meanwhile, the infl uence of SFRSSC deck pavem ent on the mid-span section is little enough to be ignored.