Determining Slipping Stress of Prestressing Strands in Confined Sections

作者：ElBatanouny Mohamed K^*; Ziehl Paul H

来源：ACI Structural Journal, 2012, 109(6): 767-776.

• confining stress
• development length
• moment capacity
• slipping

Development length and slipping stress of prestressing strands subjected to confining stress is not well-quantified and the appropriateness of the ACI 318-11 equation under such conditions can be questioned. In 1992, a test was performed on nineteen 14 in. (356 mm) square prestressed concrete piles with a clamping force applied during testing under lateral load. The findings indicated that the ACI 318-11 equation for development length of prestressing strands may not be suitable when used for sections subjected to confining stress. In this study, a modified equation that accounts for the effect of concrete confinement is discussed and compared to the published 1992 results and the ACI 318-11 equation. The moment strength of the sections is also compared using moment-curvature analysis by comparing three different slipping values: I) those obtained from experimental results; 2) the ACI 318-11 equation; and 3) the modified equation.

• 出版日期2012-12