Interest in the use of high strength steels (HSS) is growing rapidly in the global construction sector. That’s because high strength steels offer promising weight reductions, increased spans, and improved load-bearing capacity compared to alternative materials.
Cold-formed profiles made from HSS are used for many applications including roofs and facade structures, light steel framing, prefabricated modules, storage and racking systems, and silos. With new construction steel grades up to S550GD+Z, HSS offer profilers, installers and end users great potential for structural improvements. If the same thickness of steel is used, design stresses can be increased or longer spans can be achieved. Alternatively, the thickness of profiles can be reduced, resulting in significant weight savings which also reduce production and transportation costs.
European building codes and standards are being developed to include these new HSS grades. The following standards have already been revised:
Early in 2017, Hilti and ArcelorMittal initiated a technical collaboration to improve the performance of self-drilling screws for HSS. The screws are typically used to fasten sandwich panels to the cold-formed profiles of building structures.
The collaboration between Hilti and ArcelorMittal has resulted in the development of the first worldwide portfolio of fastening elements to connect sandwich panels and HSS profiles (up to S450GD). The new screws are backed by a European Technical Approval (ETA-13/0179).
The technology combines a hardened carbon-steel drill tip and stainless steel shaft. The result is improved installation speed and long-term endurance in corrosive environments.
Other applications for the screws are being tested including long-span decking and racking. Once approved, they will enlarge the applications for these screws and enable one-step fastening of HSS profiles.
This image shows:
1. Complete fixing with jumper (all waves)
2. Reduced fixing with jumper (3 waves out of 4) possible only on intermediate support (multiple supports according to technical file)
3. Fastening seam
Founded in 1941 as a family company, Hilti now designs and manufactures leading-edge technology, software, and services to power the professional construction industry.
Hilti is a global organisation employing more than 25,000 people across 120 countries. The company offers a complete service package for your projects including design software, products and tools for onsite work, repairs, testing, and consultancy. Hilti is a one-stop shop for building, worldwide.
Detail of the self-drilling screw
Copyright images: Thanate Rooprasert, Zsolt Balog / Shutterstock.com, ArcelorMittal Construction France