McKeeman, Ian and Fusiek, Gregory and Johnston, Michael and Saafi, Mohamed Ben Salem and Niewczas, Pawel and Walsh, Michael and Khan, S. (2016) First-time demonstration of measuring concrete prestress levels with metal packaged bre optic sensors. Smart Materials and Structures, 25 (9). ISSN 0964-1726
s1_ln558554_1694792204_1939656818Hwf_1746305789IdV_160619943558554PDF_HI0001.pdf - Accepted Version
Available under License Creative Commons Attribution-NonCommercial.
Download (10MB)
Abstract
In this work we present the first large-scale demonstration of metal packaged fibre Bragg grating sensors developed to monitor prestress levels in prestressed concrete. To validate the technology, strain and temperature sensors were mounted on steel prestressing strands in concrete beams and stressed up to 60% of the ultimate tensile strength of the strand. We discuss the methods and calibration procedures used to fabricate and attach the temperature and strain sensors. The use of induction brazing for packaging the fibre Bragg gratings and welding the sensors to prestressing strands eliminates the use of epoxy, making the technique suitable for high-stress monitoring in an irradiated, harsh industrial environment. Initial results based on the first week of data after stressing the beams show the strain sensors are able to monitor prestress levels in ambient conditions.