FEATURE NEWS:
A comprehensive range of bridge related products and services
Formed in 1999 through the merger of British Steel, UK, and Koninklijke Hoogovens, the Netherlands, Corus is a leading international metal company with manufacturing operations in many countries, and major plants in the UK, the Netherlands, Germany, France, Norway and the USA. To encourage faster, more precise construction and to facilitate an integrated approach to construction design, Corus has created a new centre of excellence, made-up of experts in the fields of civil engineering and structural design together with architects and a construction economist. The company can provide expert advice and design assistance on all aspects of bridges, from abutments and wing walls, through bearing design and integral connections to bridge beams, deck and parapets.
Corus supplies high-carbon wire rods, which are drawn and processed into hot dipped galvanised high-tensile wires for use in a range of cable supported bridges. The company’s product range includes high-carbon wire rods in diameters ranging from 5.0 to 13.5mm, in plain and micro-alloyed compositions to a range of tensile strengths, to EN 10016: 1995. The wire rods supplied by Corus are drawn into 5mm Ø bridge wire for use in suspension bridge cables and hangers, or 7mm Ø wire for cable-stayed applications. The bridge wire can be site spun into strand using aerial spinning equipment, or delivered to site in prefabricated bundles or strands. There are four types of strand used to form the main cables of bridges:
- Spiral Strands consisting of large diameter galvanised round wires helically spun together. The wires are stranded in one or more layers, mainly in opposite directions, to achieve the required diameter. This is the most versatile structural cable, with high breaking strength and a good strength to weight ratio;
- Locked coil strands consisting of a centre of one or more layers of large diameter galvanised round wires helically spun together. Stranded on top of this centre are one or more layers of large diameter galvanised shaped wires, mainly in opposite directions, to achieve the required diameter;
- Structural ropes that are usually of 6 strand construction helically spun around a steel core, and comprising smaller diameter galvanised wires giving a high degree of flexibility. Structural ropes offer an economic solution for temporary structures, and where greater flexibility is required;
- Parallel wire strands consisting of galvanised round wires laid-up in a hexagonal form, with a long helix. The product is then encased in a tight fitting high-density polyethylene tube. Parallel wire bundles are ideal for cable-stayed bridges, offering high-axial stiffness and an especially high modulus.
Suspension main cables are stranded from galvanised round wires with a minimum tensile strength of 1,770N/mm2. In recent years, Corus has contributed to the significant increases seen in wire tensile strength, giving rise to improved strength to weight ratios and longer span bridges. Research is continuing to develop wires with high-tensile strengths in excess of 2,000N/mm2 for the next generation of bridges. Furthermore, the corrosion protection system for bridge cables may consist of many layers. The individual wires are galvanised, various proprietary compounds can be applied to both the interior and exterior of cables, or a high-density polyethylene coating can be vacuum/pressure exuded onto the cable at the factory.
Photo: Clockwise: Tatara bridge (Japan), Kap Shui Mun (Hong Kong), Gateshead Millennium bridge (UK), Humber bridge (UK), are some examples of bridges using Corus wires and cables
Company: |
Corus |
Country: |
UK |
Fax: |
+44 20 7717 4455 |
Email: |
|
Website: |
www.corusgroup.com |