Title:
Ultimate Stress of Large-Diameter Strands in Simple Unbonded Post-Tensioned Beams
Author(s):
Wei Zhou and Yahui Hu
Publication:
Structural Journal
Volume:
115
Issue:
5
Appears on pages(s):
1379-1391
Keywords:
flexural; large-diameter strand; post-tensioned; prestressed concrete; strength; stress increase; ultimate stress; unbonded
DOI:
10.14359/51702249
Date:
9/1/2018
Abstract:
It is necessary to use large-diameter (0.7 and 0.85 in. [17.8 and 21.6 mm]) strands in unbonded post-tensioned structures to address the question on flexural response, particularly regarding its strength. A series of experiments were conducted to investigate the ultimate stress of the large-diameter strands as unbonded tendons in simply supported members. Two crucial factors—prestressing reinforcement index and global reinforcement index—are obtained from the cross-sectional equilibrium equation and test data of the present and already-existing experiments. Both crucial factors are used to derive equations to predict the increase in stress and ultimate stress of large and normal diameter strands. Evidences support the behavior and demonstrate the feasibility of large diameter strands for PT structure in terms of static loading.