Beyond ETAG 002: U-type Bonding Geometries for Structural Glazing

Consecrated in the year 2000, the Herz-Jesu Church in Munich features a glass façade with advanced, bonded loadbearing structures, Ref. [1]. The exterior of the church was built almost completely in glass, creating the timeless shape of a parallelepiped as shown in Figure 1. The structural framework to the glass façade consists of loadbearing glass beam elements with lengths of up to 6.72m bonded to stainless steel channels by silicone adhesives. This design - leading to a U-type bonding geometry by joining the glass beams to the steel stringers of parallel-flange channel-type cross-sections, see Figure 2 - required comprehensive experimental and theoretical investigations. Existing regulations such as the European guideline ETAG 002, Ref. [2], were not applicable due to their limited scope. Whereas ETAG 002 covers only simple two-sided bonding geometries (explicitly excluding three-sided bonding designs), the bonding used here is more complex geometrically, leading to significantly different mechanical characteristics.