A STUDY OF HEATED SAND WITH THERMOLUMINESCENCE

Abstract

When sand is heated slowly, an emission of light will appear and this luminescence phenomenon is called thermoluminescence (TL). TL can be observed by thermally stimulating sands at various temperatures and exposure times. The amount of TL however, is reduced if the sand is exposed to high temperature as in the case of fire. Although previous study have shown sand extracted from the heated concrete can be used in estimating maximum temperature using self-normalisation technique, this study explored different experimental approach by using solely heated sand so that the result achieved can be used as a guidance in estimating maximum thermal history reached within any building materials or structures that contain sand.There are four objective laid for this particular study. The first is to evaluate the natural TL of prepared heated sand of 100�C and 300�C at various exposure times. Second, is to compare the natural TL of heated sand treated with 10% and 30% of HC1 concentration. Third, is to estimate the maximum thermal history reached within heated sand based on self-normalisation method, and the fourth objective is to evaluate the accuracy of studied result with previous report as a benchmark result. Samples of heated sand were prepared same as that of fine-grained dating method and treated with two different HC1 concentrations of 10% and 30%. Thin layer of samples were mounted on 10mm aluminium disc before TL measurement was performed on them. In order to ensure reproducibility of the TL glow curve, five TL measurements were performed on the samples which of same exposure time, batch or homogeneity, storage and handling. Based on the results, it was found that the natural TL reduced as the exposure times increased. The effect of using higher (30%) HC1 concentration yielded 16.8% improvement and a clear TL glow curve shape. This can be explained by the elimination of impurities contained within the samples and consequently reduced the spurious TL during the TL measurement. The estimation of the maximum thermal history of heated sand using self-normalisation technique is dependent upon the duration of thermal exposure. The studied result shows �15% accuracy when compared with previous published result (100%).