Prestress Loss of Lower Flange Concrete of Preflex Beams during the Storage Period and its Influence on Load Deflection Behavior
By Tetsuo Mochida and Nobuo Nakayama
Concrete Research and Technology
Vol.22, No.2, May 2011 (Issue 56)
- Synopsis:
- Prestress loss of lower flange concrete due to creep and shrinkage during the storage period is regarded as one of the main design loads for long span preflexed beams. Rigorous and approximate solutions for the prestress loss are proposed and the creep coefficient and the shrinkage strain are assessed based on test result of a model specimen. The cracking load and the post cracking behavior of the specimen are accurately estimated using the assessed values in the proposed formula. Furthermore, the cracking load is predicted to decrease by about 15 percent when the storage period is increased from two weeks to two months.
- Keywords:
- preflexed beam, storafe period, creep, shrinkage, prestress loss, cracking load, scaled model test
