Study on Creep Behavior of Prestressed Concrete Beams for Rail Transportation during Construction Stage

On the principle of equivalent stresses in mid-span sections and similar construction procession,6 large scale models simulated practical prestressed concrete track girders in the proportion of 1∶5.Creep behaviors were tested during the construction stage.The research with an emphasis on the effects of concrete,tensioning methods as well as stress differences between upper and lower fibers on creep deformation of track girders was carried out.Moreover,software SOFiSTiK and the step-by-step FEM analysis program were applied to the time-dependent full-range analysis of the models during the construction stage,and computing values of the program correspond well to the experimental results.The error is less than 10%.In addition,design suggestions take concrete,tensioning methods as well as stress differences between upper and lower fibers into account.The fruits are useful to the design of prestressed concrete beams for rail transportation and effective control of creep deformation.