NEW APPROACH TO SAFETY ESTIMATION OF HEAT SOAK TESTED THERMALLY TOUGHENED SAFETY GLASS

摘要

At revision of EN 14179-1 describing the Heat Soak Test (HST) for Thermally Toughened Building Glass, a holding temperature decrease from 290°C to 260°C and a limitation of the heating-up ramp speed to three degrees Celsius per minute are comprised. Temperature decrease was necessary because previous R&D had shown a principal incompleteness of the NiS a to β transformation at too high temperature. On the other hand, a discussion on the holding time started because, following Arrhenius' law, temperature decrease should be compensated by longer time. At this occasion, in order to help to clarify the situation, we publish new data from seldom breakages on buildings, collected over the past 30 years, and compare the results with a dataset from breakages in Heat Soak Test.