Title: Effect of Heat Exposure Duration of the Thermoluminescence of Concrete

Author(s): Michael Y. L. Chew

Publication: Materials Journal

Volume: 90

Issue: 4

Appears on pages(s): 319-322

Keywords: concretes; exposure; fires; Materials Research

DOI: 10.14359/3882

Date: 7/1/1993

Abstract:
The use of a self-normalizing technique for the interpretation of thermoluminescence (TL) test results, for the assessment of the maximum temperature attained during a fire in a heated concrete, has been previously reported. This paper describes further study of the effect of the heating duration on the residual TL of a heated concrete. The study has shown that the reduction of TL reduces with exposure time, so that the greatest reduction in TL for any given temperature occurs during the initial stages of heating. The difference in the reduction of TL between exposure times of 3, 4, and 5 hr was found difficult to detect. This is a drawback of TL in assessing the thermal history of a heated concrete accurately if the exposure time is long, although such long durations are rare in actual cases. Methods were developed to estimate the upper bound thermal exposure experienced by a concrete with aggregates not previously heated. A curve relating TL estimates with the lower bound compressive strength f' c of concrete is suggested.