부산대학교 도서관

Thirteen commercially available construction sealants were evaluated according to variations of ASTM C 1248 fluid migration tests. All sealant specimens were compressed by 50% during the exposure period. A first set of sealants was subjected in the compressed state to the exposure conditions described in ASTM C-1248, namely (a- and a-2) 14 days and 28 days at ambient laboratory conditions, (b-1 and b-2) 14 days and 28 days at 70 C in a forced draft oven, and (c-1 and c-2) 14 days and 28 days in an ultraviolet fluorescent test chamber (Q-U-V Weather-o-meter) with UVA 340 type bulbs. The same set of sealants was also subjected in the compressed state to exposure condition (d) 104 day storage at 70 C in a forced draft oven. After completion of exposures (b) and (c), the uncompressed specimens were stored at ambient laboratory conditions for another 18 months (exposure condition (e) and (f)). A second set of sealants were subjected only to exposure conditions (b) and (d). The sealants were evaluated on the following substrates: concrete, granite, limestone, and marble. The width of the stain (degree of staining) was measured on the substrate surface and across the cross-section of the substrate. Results were compared to previously documented outdoor weathering tests for a correlation. It is suggested that ASTM C 1248 with a 28 day exposure in heat and QUV gives the best correlation.