In modern architecture, glass is increasingly being used as a structural material. For example, glass fins, roof beams, facade supports and even entire glass bridges are being made from laminated safety glass. In the past, however, this was much restricted by the achievable dimensions. Glas Trosch took up the challenge, presenting for the first time a 21 metre long laminated glass beam at Glasstec 2010 in Dusseldorf. This world-first met with considerable interest from architects and builders. That prompted the company to conduct a scientific investigation on the load-bearing behaviour of large beams of this type. Various testing and analytical investigations have been done within the last year to learn more about the load carriage behaviour of the laminated beams. The test program is based on small scale beams with total length of 3.2m loaded in a 4 point bending configuration. The first test series was performed with different types of joint layouts and different glass types (annealed, heat strengthened and fully tempered). The specimens were continuously loaded until breakage within a time period of around 3-5 minutes. Besides the various short term tests, testing on in plane loaded single glass sheets has been done to compare the breaking loads with the laminated beams. Additional testing on long term behaviour of the beams under increased temperatures is currently conducted. Finally, there is planned to execute a long term test in large scale to verify the conclusions from the above described test program. This paper shoes the latest findings regarding the short and long-term carriage characteristics.
