~~by

Kyle Karschner1 and Andrew Scanlon2

Long- time multipliers are commonly used in design codes and specifications such as CSA A23.3 and ACI 318 to compute time-dependent deflections of reinforced concrete members. These multipliers are convenient for design due to their simplicity of application. However, as a result of their simplicity they do not account for many factors that influence time-dependent deflections. This paper presents an analytical method based on a time-stepping procedure to trace deformations in cracked and uncracked sections under sustained loads. A parametric study is conducted to assess the sensitivity of the solution to the various parameters involved and implications for design are discussed.

1. SGH, Boston, Massachusetts.

2. Contact author: Penn State University, axs21@psu.edu, 814 867 0151