Title:
Ten-Year Study on Steel Fiber-Reinforced Concrete Beams Under Sustained Loads
Author(s):
Kiang Hwee Tan and Mithun Kumar Saha
Publication:
Structural Journal
Volume:
102
Issue:
3
Appears on pages(s):
472-480
Keywords:
beam; cracking; deflection; stiffness; strength
DOI:
10.14359/14419
Date:
5/1/2005
Abstract:
Nine reinforced concrete beams with discrete steel fiber contents ranging from 0 to 2% were subjected to sustained flexural loading between 0.35 to 0.8 times the flexural capacity over a period of 10 years. The long-term deflections and maximum crack widths were found to decrease with increasing steel fiber content, with a reduction of 34 and 58%, respectively, at the end of the 10-year period in the case of the 2% fiber content. The deflections and crack widths were smaller for lower sustained loads. The modified ACI approach and effective modulus method predict the long-term deflections very well, while the adjusted effective modulus method slightly underestimates the same. Under four-point loading, the beams showed a reduced stiffness in the initial stage. After the previously sustained load level was attained, however, the beams exhibited essentially the same load-deflection characteristics as the corresponding ones that were not subjected to sustained loadings.