Effective Use of High Strength S690 Steel in Construction

Lead  Prof. CHUNG Kwok Fai

Department of Civil and Environmental Engineering | Chinese National Engineering Research Centre for Steel Construction (Hong Kong Branch)

High strength S690 steel has been used in established products for the last two decades. For examples, in thin steel strips in vehicles and thick plates used in large machinery and heavy lifting equipment. Yet, its application in construction has been limited as welding, which is required to assemble thick plates into large structural members for buildings and bridges, is technically demanding and leads to reductions in mechanical properties.

Prof. Chung Kwok Fai and his team have overcome these long-standing barriers to the adoption of S690 steel in construction. The team brought together multi-disciplinary expertise and developed a series of effective welding procedures that, for the first time, do not deteriorate the steel’s mechanical properties.

Prof. Chung’s research has reshaped the professional practice. It has been incorporated into the Code of Practice for the Structural Use of Steel of the Buildings Department of the HKSAR Government, and influenced the development of national and international construction standards.

The adoption of S690 steel enables lighter, greener, more economical construction. In the construction of the Cross Bay Link in Hong Kong, which consists of a 214-metre double arch steel bridge, the use of S690 steel has saved HK$100million and reduced carbon emissions by 25%. The proven advantages support the wider adoption of S690 steel in public works projects.