The design of stay cables has continuously evolved since the construction of the first modern cable stayed bridge in Sweden in 1955. Cables are comprised of high-strength steel wires, strands or bars. In most cases, a high-density polyethylene pipe encases the steel elements. In the U.S. practice, cement grout has generally been used to fill the space inside the pipe and between steel elements. This practice however is being abandoned for newly designed bridges.
CTLGroup currently operates the world’s highest capacity and most extensive independent stay cable testing facility. Our experts have tested almost all available stay cable systems from various manufacturers for qualification and development programs. This has given CTLGroup an extensive and in-depth view into advantages and disadvantages of each system in comparison with the others.
In 1991, CTLGroup established a center for full-scale fatigue evaluation of bridge cables, and has since conducted over 140 full-scale fatigue tests on stay cables and anchorage systems. In addition to axial tension tests of straight cables, CTLGroup engineers conducted the first ever full-scale axial-flexural fatigue test of bridge stay cable in the United States for the Clark River Bridge and the C&D Canal Bridge.