He also discussed some of the changes since GPD 2011, which include, for example, larger glass units, improvements in stair Stringer Beams, the availability of large unit processing as well as the experience in fabrication and installation and “jumbo size glass.” Bostick said each played significant roles as the industry overcame the challenges of overcoming brittleness in connecting glass to glass while having the connections disappear within the transparency of the glass. Likewise, he said initial point fittings laminated into structural glass units were tested in the year 2002 with one side of the fitting laminated and one side done as a more traditional through the glass bolted connections. In the past two years the choices have been expanded, he said.
As an example, he cited a new glass cube structure (think Apple Store) that is fully laminated with fittings where both sides of the fitting are laminated within the two glass units to be joined.
This connection concept also was used in the stair stringer in the glass stair in Hamburg, where the 100 or so tread connectors were buried as a 57-mm round “nut” with threaded hole in the five layers of glass. The only connector not laminated within was the stair stringer to upper slab connection where the loads did not allow laminated fittings.
Bostick also said inquiries regarding large size glazing have been on the rise.
Interesting to note is that the fabrication tolerances for extra-large size glazing tend to be tighter than on more normal size glass units. Bostick said this is logical;the tolerances of the surrounding structure tend to remain and the same tolerance over the greater unit length or width means tighter tolerance requirements. He added that more exact fabrication processes and the machines to achieve this should be expected in the future.
Curved glass is also appearing in more projects than ever, he said. This is due, in part, to CAD programs that make it easier to draw curved forms, and a desire by the architects to design something different, not yet done . He also said it is partially due to manufacturers showing that curved glass is technically possible, though often with many limits. The biggest hurdle yet, he noted, is cost as such curved units can be expensive depending on a lot of different factors. The fact is, Bostick explained, that there is a trend towards more curved glazing.