High Strength Steel Applications

Engineering , Construction
March 15, 2024

Table Of Contents

Introduction

In modern infrastructure development, ultra-high-strength structural steel (HSS) has become a key factor in driving new quality productive forces. This article aims to explore its innovative applications in Hong Kong’s construction industry and its contributions to sustainable development.

A New Transformation in Hong Kong’s Construction Industry

The construction industry in the Hong Kong Special Administrative Region faces multiple challenges, including high construction costs, conservative design standards, an aging workforce, labor shortages, unstable material supply, and high labor demands in construction processes. To overcome these bottlenecks, the Hong Kong SAR government is actively promoting the industry’s adoption of efficient construction technologies, aiming for lightweight design and making good use of prefabrication methods to enhance the economic benefits of public works and reduce construction costs.

Characteristics of Ultra-High-Strength Structural Steel

Ultra-high-strength structural steel is increasingly used in building and bridge steel structures due to its green, low-carbon, and safe attributes:

Strength and Lightweight: Ultra-high-strength steel with strengths ranging from 690MPa to 960MPa can withstand higher stresses than ordinary steel, reducing material usage and enabling lightweight structural design.
Corrosion Resistance: Excellent corrosion resistance extends the service life of steel structures, reducing the need for maintenance and replacement, thus lowering lifecycle costs.
Safety: High-strength steel provides better seismic resistance, enhancing the safety of structures.

The world's first S960 ultra-high-strength pedestrian bridge over a river successfully completed its closure on the 75th anniversary of the founding of the People's Republic of China

Innovative Application Examples

The Tseung Kwan O Cross Bay Link in Hong Kong efficiently utilized S690 high-strength steel, employing advanced welding techniques and non-destructive testing to ensure construction quality, reduce structural weight, and lower construction and maintenance costs. The Macau Bridge successfully applied Q690 high-strength steel, achieving on-site assembly, improving work efficiency, reducing carbon emissions, and promoting sustainable development.

Breakthroughs and Challenges of S960 Steel

In 2024, the Fanling Bypass East section of the Northern Metropolis in Hong Kong adopted domestically produced S960-grade steel for the first time to construct two pedestrian steel bridges, designed according to EU steel structure technical standards, significantly reducing bridge weight and transportation costs. However, due to the European standards used in Hong Kong’s bridge design only covering steel up to S700, local engineers lack theoretical and technical guidance for the higher-grade S960 steel. Therefore, the Hong Kong SAR government, through an integrated collaboration mechanism involving government, industry, academia, research, and application, has worked with CNERC Hong Kong Division, local design, and construction companies to jointly develop design schemes and welding techniques for S960 steel, breaking barriers to the application of new materials and technologies.

Future Outlook

The promotion and application of ultra-high-strength structural steel are significant for developing new quality productive forces, driving progress in materials science and production technology, and promoting industry upgrade and green construction. Large-scale infrastructure projects in Hong Kong and Macau have set a shining example for domestically produced ultra-high-strength steel structures and technologies to “go global” and support the “Belt and Road” initiative. With technological breakthroughs and expanded applications, ultra-high-strength structural steel will play an increasingly important role in the development of new quality productive forces.

Image Captions

Figure 1: The world’s first S960 ultra-high-strength pedestrian bridge over a river successfully closed on the 75th anniversary of the founding of the People’s Republic of China.

Figure 2: Prefabricated semi-circular pedestrian bridge for the Fanling Bypass East project in Hong Kong.