Study on Effective Stress Estimation Method for Concrete Members
By Kyoji Niitani, Hiroshi Watase, Kenji Sakata and Toshiki Ayano
Concrete Research and Technology
Vol.20, No.2, May. 2009 (Issue 50)
- Synopsis:
- Numbers of concrete structures have been constructed and they contribute to creation of infrastructures. It is important to know the stress of concrete acting on existing structures in order to maintain structures appropriately. However, it is difficult to know the actual stress for several reasons. The major reason is differences between the design stress conditions and the actual stress conditions. The causes are internal restrictions due to creep and shrinkage of concrete. In this study, the mechanisms of internal restrictions are investigated through various experiments on creep and shrinkage of concrete, and a new effective stress estimetion method is proposed. The method is based on stress release technique. It can separate stresses caused by internal restriction from the total stress. Also the accuracy of estimated stress has been improved by providing a specified measuring method. From verification tests using test specimens and actual structures, it was confirmed that the method is useful for setting maintenance level of structures.
- Keywords:
- effective stress, internal restrained stress, shrinkage, creep, prestress
