Applicability of Modern Analytical Techniques to Detection of Changes in Roofing Membrane Materials Brought About By Heat Aging.
Applicability of Modern Analytical Techniques to
Detection of Changes in Roofing Membrane Materials
Brought About By Heat Aging.
Rossiter, W. J., Jr.; Byrd, W. E.; Roberts, W. E.;
Bailey, D. M.
International Waterproofing Association. International
Congress, 9th. April 26-28, 1995, Amsterdam,
Netherlands, International Waterproofing Association,
244-242 pp, 1995.
building technology; roofs; heat; aging; membranes
The U.S. Army Construction Engineering Research (CERL)
has been investigating the development of a test
methodology for evaluating the service life of roofing
membrane materials. As part of this effort, CERL
conducted a study to investigate the applicability of
strain energy (a mechanical test) and Fourier transform
infrared (FTIR) spectroscopy (a chemical analysis) as
methods for characterizing changes that roofing membrane
materials may undergo upon exposure to elevated
temperatures. In the case of FTIR, the intent was to
evaluate whether changes in the carbonyl index as a
function of thermal exposure could be used as an
indicator of the stability of the membrane materials.
The carbonyl index is the ratio of the intensity of the
carbonyl absorption band (i.e., C=O) to that of another
band (such as C-H stretching or bending) in the
spectrum. Increases in a material's carbonyl index
after exposure may be an indication that oxidation
occurred during the exposure. Measurements of both
strain energy and carbonyl index have been used for
specific types of membrane materials. Neither has been
applied universally to the variety of membrane materials