Title: Flexural Fatigue Behaviour of Prestressed Concrete Beams Using Aramid-Fiber Tendons

Author(s): K. Iwamoto, Y. Uchita, N. Takagi, and T. Kojima

Publication: Symposium Paper

Volume: 138

Issue:

Appears on pages(s): 509-524

Keywords: beams (supports); fatigue (materials); fatigue tests; fibers; flexural strength; prestressed concrete; prestressing; prestressing steels; pretensioning; strength; wires; Structural Research

DOI: 10.14359/3937

Date: 9/1/1993

Abstract:
Fatigue tests of pretensioned concrete beams with aramid fiber rods as prestressing tendons were carried out to investigate the effects of upper load ratio and initial tendon tension on the beam fatigue strength and deformation. The beams were 15 x 15 x 210 cm. Three levels of initial tendon tension were chosen in the lower beam tendons, approximately 40, 60, and 70 percent of the rod tensile strength. Symmetrical two-point loading was applied to the beam. The upper load in cyclic loading was varied from 45 to 80 percent of the static ultimate load, and the lower load was constant at 4.9 kN. Sinusoidal loading of 4 Hz was applied. The beams with aramid fiber tendons behaved well in fatigue performance, comparable to beams with prestressing wires. The effect of initial tendon tension on beam fatigue life was not observed; fatigue life was determined by the upper load. The fatigue strength at 2 million cycles of loading was more than 65 percent of the static ultimate beam strength.