Analysis on Shrinkage Effects of Concrete Interfaces in Long-Span Continuous Rigid Frame Bridges

Based on Jintang Bridge's east navigation channel,a 216-meter continuous rigid frame bridge,effects on shrinkage stress distribution characteristic at interfaces between concrete with different ages were analyzed.Combining spatial finite element method and theoretical way,shrinkage effects at interfaces under various factors were compared such as different casting time intervals,different reinforcement ratios,different average environmental relative humidity and effects under different codes.Results show that effects on shrinkage stress at interfaces caused by section property break are more obvious than that by different ages of concrete,and shrinkage stress increases with a small increment as casting time interval and reinforcement ratios increase,while humidity has the most significant influence on shrinkage effects.Results also show that shrinkage stress level calculated under AASHTO is much more reasonable than that under code JTG D62—2004 in concrete members with large thickness.Establishing a ceiling on theoretical thickness in JTG D62—2004 is advised.