Abstract
To find out the most suitable creep function of aging concrete, authors at first began with the studies of creep for very old concrete (the hydration of cement is complete and we defined it as the basic condition of concrete, and the creep curve is regarded to depend only on the loading time). The results of the present study are summarized as follows : (1) The incremental creep poisson's ratio [numerical formula], which is defined as the ratio of incremental lateral strain △ε_2 and incremental longtudinal one △ε_1 at a given time, approaches to the values of 0.5 after the loading for 70-100 days. (2) Since both experimental results and proposed creep mechanisms, the longitudinal specific creep strain C_B(t) can be separated two components : one is recoverable and the other is irrecoverable. (3) The lateral, volumetric and deviatoric specific creep strain are calculated with C_B(t) and one parameter α. These calculataed values are agree well with the experimental results.
