Лако-красочные материалы — производство

Steel structures in the building and construction industry are currently those with the greatest degree of prefabrication. The established joining technologies in structural steelwork find limitations in the joining of high-strength steel grades and lightweight constructions in terms ofconsistent load distribution, destruction

of the basic material by boreholes and the durability of welded joints under dynamic load conditions. At present, bonding (as an alternative to welding and screwing) finds only a limited range of application for structural joining in steel constructions.

The first attempts to introduce bonding technology into structural steel engineer­ing date back to 1953, when two pipeline bridges were built using a hybrid bonding technique (high-strength friction-grip HSFGbolts + bonding) across the Lippe-Ems — Kanal, a canal in Marl/Germany, and in the bonding ofcorrugated steel to supporting girders in roofing applications.

In cladding and glazing, adhesive bonding and sealing today meets an increasing number of successful and impressive applications. Due to the low specific weight (ca.

2.8 g cm3, close to that of aluminum) and brittleness of glass, adhesively bonded glass structures show a superior mechanical performance compared to mechanical fastening of glass by means of bolting and clamping.

The European Technical Approval Guideline ETAG 002 for Structural Sealant Glazing Systems (SSGS) regulates the use of building elements made from adhe­sively bonded glass panels as facades and roofs, or parts thereof, with glazing at any angle between vertical and 7° above horizontal. The guideline covers the general requirements for system assessment and the specific requirements for mechanically supported and unsupported systems, where the structural seal adhesion surfaces are glass (either uncoated or with an inorganic coating) and anodized aluminum or stainless steel. This guideline specifically addresses the design, manufacture and aging properties of silicone adhesives.

Recently, PSAs have been used successfully in glazing applications to bond glass panels to supporting metal framework. The viscoelastic adhesive fixture avoids stress concentrations in crack-sensitive lightweight glass panels, and also compensates for the difference in thermal expansion between glass and other materials such as an aluminum framework (Figure 8.16).

8.4