Comparison on Shrinkage Effects at Concrete Interfaces in Long Span Girder Bridges between Chinese and American Codes
LI Xiao xiang,SHI Xue fei,RUAN Xin and FENG Dian shi
DOI:10.11835/j.issn.1674-4764.2009.05.016
Received May 15, 2009,Revised , Accepted , Available online July 01, 2015
Volume ,2009,Pages 86-89
- Abstract
Stress, due to shrinkage characteristic difference resulting from different concrete age at typical interface parts in long span rigid frame bridges, was analyzed based on Chinese and American codes. Reasons for large discrepancy between results under the two codes were also discussed. It was shown that shrinkage stress level calculated under AASHTO was more reasonable than that under Chinese code (JTGD 622004) for concrete members with large thickness. Concrete at interface parts was easy to crack when casting time interval was long. According to JTGD 622004, stress at interfaces was always small under different casting time intervals, while stress at position with mutation section was more significant. It was necessary to set an upper limit to theoretical thickness in JTGD 622004, and 300 mm was recommended. Finally, some design and construction approaches were put forward.