Impedance spectroscopy as a tool for moisture uptake monitoring in construction composites during service
Artikel i vetenskaplig tidskrift, 2018

This is a first study comparing dielectric spectroscopy and gravimetric measurements of moisture uptake in pultruded glass fibre reinforced polymers (FRPs). Specimens were subjected to sub-Tg hygrothermal aging for 224 days. Impedance spectra in the frequency range 0.1 Hz to 10 MHz were captured during exposure and compared with gravimetric measurements. Moisture concentration was found to increase the FRP's dielectric permittivity monotonically and decrease bulk resistance. High quality dielectric data was obtained as moisture uptake is independent of inherent changes suggested by mass loss which compromise gravimetry. Dielectric measurements remained sensitive to moisture despite significant mass loss, which typically distorts the weight gain process complicating the commonly adopted gravimetric methodology. Real-time dielectric measurements were obtained from FRP specimens continuously immersed in water and without making use of any additional sensing elements. The novel approach adopted is of high commercial impact as moisture uptake control is recognized as a significant problem by industry.

Författare

Sotirios Grammatikos

Chalmers, Arkitektur och samhällsbyggnadsteknik, Byggnadsteknologi

R. J. Ball

University of Bath

M. Evernden

University of Bath

R.G. Jones

Mott MacDonald Group Limited

Composites Part A: Applied Science and Manufacturing

1359-835X (ISSN)

Vol. 105 108-117

Ämneskategorier

Medicinsk laboratorie- och mätteknik

Pappers-, massa- och fiberteknik

Kompositmaterial och -teknik

DOI

10.1016/j.compositesa.2017.11.006