Title: Determining Time Dependent Losses Of Prestress with Due Consideration of Aging Coefficient and Percentage of Steel
Author(s): T. K. Bandyopadhyay and B. Sengupta
Publication: Journal Proceedings
Appears on pages(s): 236-243
Keywords: age; creep properties; modulus of elasticity; prestressed concrete; prestressing steels; prestress loss; stiffness.
Aging coefficient has been calculated by a numerical method using a step-by-step approach. The method takes the following into account to attain an unbounded value of creep strain: effect of steel ratio, stiffness coefficient of the member, creep coefficient, concrete aging, and variation of modulus of elasticity of concrete. The calculations are extended to determine the loss in steel stress, showing clearly the accuracy achieved due to the consideration of proper aging coefficient accounting for the reinforcement present which is normally not given due attention. A few steps of the approach are included in the Appendix to show the steps followed for arriving at final values us-ing a Burroughs 6700 computer.