Shear Modulus of Cylindrical CFRP Tendons Exposed to Moisture
Publication: Journal of Composites for Construction
Volume 19, Issue 3
Abstract
Two groups of cylindrical carbon fiber-reinforced polymer (CFRP) tendons were exposed in distilled water at 23°C and 60°C to study the diffusion mechanisms and the effect of moisture uptake on the tendon shear modulus. The two tendon groups had different manufacturing processes, so DMA tests and optical microscopy were used to help characterize the materials. Mass uptake readings of tendon samples were recorded and the uptake generally agreed with Fickian predictions. To study the time-dependent changes in the matrix stiffness due to exposure, torsion tests within the elastic range of loading were conducted. The tendon shear modulus was then derived from the torque versus twist plots. For both groups of tendons the measured shear modulus decreased due to exposure in water. A long-term shear modulus prediction model was developed to relate the tendon torsional shear stiffness and the moisture concentration and the results appeared to agree well with the experimental findings.
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Acknowledgments
We are grateful to SACAC for their technical and financial support. We also appreciate the financial support from the Onassis Foundation.
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Published In
Journal of Composites for Construction
Volume 19 • Issue 3 • June 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Mar 20, 2014
Accepted: Jul 21, 2014
Published online: Sep 2, 2014
Discussion open until: Feb 2, 2015
Published in print: Jun 1, 2015
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