Influence of mechanical strength on the characteristics of aluminium profiled glazed fire door

This study examined the impact of mechanical fatigue-caused by repeated opening and closing-on the fire resistance and airtightness of single-leaf glazed aluminium-profiled fire doors with EI 30 and EI 60 ratings. Twelve door specimens were tested, with ten undergoing mechanical cycling ranging from 50,000 to 1,000,000 cycles prior to fire resistance evaluation. The research included air permeability measurements, gap assessments, self-closing performance, and full-scale fire resistance tests based on integrity and insulation criteria. While fire resistance was not significantly affected by mechanical fatigue-even after one million cycles-a substantial increase in air permeability was observed. This occurred despite only minor changes in rebate gap dimensions, suggesting that frequent use could notably impair smoke control performance. Additionally, the greatest structural deformations were recorded within the first five minutes of fire exposure, highlighting a discrepancy with current European testing methodology. The findings indicated that while fire resistance remains stable under extensive use, smoke tightness may degrade considerably, warranting further investigation.