The Bearing Capacity Research Of Durability Decayed PC Simple Beam

With the rapid development of our economy and overall national strength increasing, the traffic cause is rising steadily. Bridge in the transportation industry, occupies a pivotal position, especially in many big cities such as such as north, traffic is increasing, it is due to the rising number of bridges that got a certain ease traffic jams. As the disease continues to appear, however, we have to pay attention to the durability of the bridge. Although the study of the pre-stressed concrete bridge’s durability research has certain results, the mechanical behavior and bearing capacity of durability decayed structures remain to be further studied.First, this paper introduces the definition of the durability of bridge structure, illustrates the necessity and significance through a series of data, and then points out the main content and significance of this study based on summarizations of the domestic and foreign research on durability of concrete bridge.Second, combining with the characteristics of prestressed concrete bridge structures, the diseases of durability, the causes and the influence factors are analyzed. The experimental studies on the concrete strength after carbonization or freezing and thawing, the corrosion rate of ordinary steel bar, the relationship between initial pre-stress size and corrosion rate of the steel strand, mechanical properties of corroded steel strands and the corrosion rate of anchorages of PC simple beam. Third, based the four parameters which are the different initial pre-stress, the time-varying steel strand, the time-varying strength of concrete and the concrete strength after freezing and thawing, the mechanical behavior of pre-stressed simply supported beam after durability decay, the bearing capacity research of durability decayed PC simple beam are studied by the finite element software ANSYS. The beam mid-span deflection, the concrete stress and strain of the span bottom centre and the stress of the steel strand are analyzed through the single factor of PC simple beam durability. Then, the influence of PC simple beam bearing capacity and the change of strand stress owing to the four single factor durability degradation are obtained.At the end of the paper based on the bearing capacity research of the single factor durability decayed PC simple beam, the bearing capacity research of multi-factor durability decayed PC simple beam are studied by the finite element software ANSYS. The beam mid-span deflection, the concrete stress and strain of the span bottom centre and the stress of the steel strand are analyzed, and some conclusions are obtained, which are the influence of PC simple beam bearing capacity and the change of strand stress because of the multi-factor durability degradation.