Experimental Study on Smart Anchor Head

Since prestressed concrete members rely on the tensile strength of the prestressing strands to resist loads, loss of even few them could result catastrophic. Therefore, it is important to measure present residual prestress force. Although there are some techniques for obtaining present prestress force, some problems still remain. One method is to install load cell in front of anchor head but this may increase cost. Load cell is a transducer using the elastic material property. Anchor head is also an elastic material and this might result in monitoring monitor present prestress force. Features of fiber optic sensor such as small size, great sensitivity, high durability can assign sensing function to anchor head. This paper presents the concept of smart anchor head which acts as load cell and experiment for the applicability of it. Test results showed the smart anchor head worked good and strong linear relationship between load and response.

Authors:

• Young-Jun You
• Ki-Tae Park
• Kyu-Wan Lee

Keywords:

• SHM
• prestress force
• anchor head
• fiber optic sensor

References:

[1] E. Proverbio and L. M. Bonaccorsi, "Failure Of Prestressing Steel
Induced By Crevice Corrosion In Prestressed Concrete Structures," 9th
International Conference on the Durability of Building Materials and
Components, Brisbane, Australia, 2002.
[2] H. Scheel and B. Hillemeir, "Location of prestressing steel fractures in
concrete," Journal of Materials in Civil Engineering, vol. 15, no. 5, pp.
228-234, 2003.
[3] A. T. Bashir, A. Jalil, and A. R. Rosly, "The Functionality of Fiber Bragg
Grating Sensor Compared to that of Foil Gauge," American Journal of
Applied Sciences, vol. 2, no. 12, pp. 1600-1605, 2005.
[4] G. Bahareh and N. Hooman, "Fiber Optic Sensors," World Academy of
Science, Engineering and Technology, vol. 42, pp. 297-307, 2008.
[5] M. G. Xu, H. Geiger, J. L. Archambault, L. Reekie, and J. P. Dakin,
"Novel interrogating system for fiber Bragg grating sensors using an
acoustic-optic tunable filter," Electronics Letters, vol. 29, no. 17, pp.
1510-1511, 1993.
[6] K.-T. Lau, "Fibre-optic sensors and smart composites for concrete
applications," Magazine of Concrete Research, vol. 55, no. 1, pp. 19-34,
2003.