Bridges With Reinforced Concrete Hollow Beam Fatigue Performance And Life Prediction

Reinforced concrete bridge occupies a large percentage of the existing bridges in our country. Over the past years, domestic and foreign experts have made a number of valuable academic and practical achievements on concrete structure fatigue, the steel bar corrosion, structural performance degradation and remaining life prediction. Fatigue detection, evaluation and reinforcement technology of bridge structure, and the remaining service life prediction based on above-mentioned have now become international and domestic engineering hotspot. Aiming at fatigue performance and fatigue life prediction of bridge reinforced concrete hollow beam, the main research work in this text was focused on:1) Static loading and fatigue tests were done on 6 reinforced concrete hollow beams with each of them under a different load range.we researched on the concrete strain in the compression zone and the steel strain in the tension zone, mid span deflection and crack development under different fatigue times. We also investigated the service life under different fatigue load ranges.2) We fitted the data obtained under fatigue loading into S—N curves. These provided the basis for the life prediction of bridges that are made by reinforced concrete hollow beams.3) After the reinforced concrete hollow beam's fatigue failure, static tests on some of the fatigued steel bars were carried out to get an overall understanding on the mechanical performance degradation of the steel bars.4) We explored the possibility of establishing the load spectrum and random fatigue test plan. Using the S—N curve and the current cumulative fatigue damage theory, we created a method to predict the fatigue life of reinforced concrete hollow beam under random variation loads. The test data also provided verification on the residual stiffness analysis method on hollow reinforced concrete beam fatigue damage analysis.