Research On Creep Of High-performance Concrete Taking Account Of Reinforcement Impact

The issue of creep of the concrete has not been completely solved for a long time. Due to the problem that the designers probably have not forecasted the creep of the concrete, the deflection of many beams of bridges are seriously out of control after completion in and abroad. Some tend the alignment of the bridge irregular, others even make the bridges collapse, resulting in serious loss of lives and property. The issue of creep would be a great obstacle that is hard to handle and is to be solved. Although we have made a great achievement on the research of creep and accumulated a great amount of practical experiences, we have not taken much impact of bars into account in the research.Based on Fu river bridge on the 6th contract of Wuhan ring road, this paper has initiated the research of the reinforced impact on the creep of the concrete bridge. After elaborating some basic theory on creep, it has preliminarily explored the mechanism of reinforced impacts on creep. Moreover, referring to present projects, some finite element models, not having taken reinforced impact into account, value of creep and cumulative value of creep could be acquired under different loading duration in the first three months, that have been established in order to make an exploration about the reason of the differences after comparing the result under many different factors such as total deflection of creep, the coefficient of creep and etc. It is found that the reinforcement has little effect on the total deformation of creep-less than 10%. The effect on creep coefficient is around 0.15. If not considering the reinforced impact, the effect on theoretical creep deformation would exceed 15%.Eventually, some virtual ratio of reinforcement has been simulated in this paper. And then the influence on creep under different longitudinal ratio of reinforcement has been analyzed. As a result, with the increasing ratio of reinforcement, the creep is not based on the linear declination. When the ratio of reinforcement is approaching 5%, the creep deformation will be less than half of that without reinforced impact.According to the equivalent elastic modulus method and considering transverse and vertical reinforced impact, With the increasing ratio of transverse and vertical reinforcement, under the condition that ratio of vertical and transverse reinforcement increase in every one percentage point, the creep cumulative deformation under the impact of reinforcement, comparing with that not considering the impact of reinforcement, would be on a declination about 2～3 percentage points. A number of useful conclusions on engineering design and construction have been achieved.