Evolution of China’s Steel Reinforcing Standards
The use of reinforced steel in building structures has long been a practice, with steel bars or mesh embedded into a concrete structure in order to increase its strength and resist the forces of applied loads. This technology was developed in China as early as 3000 BC; however, the exact methods and techniques used back then have been lost in the pages of time. Since then, the use of reinforced steel has become a necessity in building structures and the standards in which they are manufactured have evolved in order to meet the varying demands of construction projects. In this paper, the evolution of China’s steel reinforcing standards will be examined and discussed.
From the beginning of its use in China, the quality and strength of steel reinforcing bars was determined by the source of the raw material and the manufacturing process. As such, there were no set standards for production of steel reinforcing bars until the advent of modern steelworks. The first steelworks to appear in China were built in 1910, relying heavily on imported technology from European countries. These steelworks followed the European standards of production, resulting in a consistent quality and strength of steel reinforcing bars.
With the development of the steel industry in China, more steel plants began to appear around the country, each producing their own type of reinforcing bar. Unfortunately, this lack of production standards led to inconsistent quality between the different steel products. In 1951, the Chinese government introduced the Steel Reinforcing Bar Standard, which was designed to create a consistent production process across the country. This standard was based on the existing European standards but also introduced a number of additional standards such as the requirements for rust-proofing, strength testing, and size.
In 2002, the Chinese government introduced the GB 1499.2-2007 Steel Reinforcement Standard. This was the first revision of the original 1951 standard and incorporated a significant number of changes. These changes included the introduction of new mechanical properties for reinforcing steel, additional requirements for hardness testing, and additions to the requirements for deformation and strength. This revision also established standardised tests for the mechanical properties of steel bars, allowing them to be more easily compared between manufacturers.
In the years since the 2007 revision, there have been two additional revisions to the standard. The 2010 revision improved the toughness requirements for steel rebars and also introduced stricter requirements for the surface treatment of steel. The 2013 revision of the standard significantly reduced the tolerance for deformations and deviations in steel bars, leading to an overall improvement in the quality and strength of the steel.
As the demands of the construction industry continue to evolve, so too will the standard of steel reinforcing bars. Through continual revisions, the Chinese government is ensuring that the steel reinforcing bars used in construction meet the highest of safety and quality standards. Through the continual evolution of the standard, China’s steel reinforcing bars have been able to meet the demands of an ever changing construction industry and ensure the safety and reliability of structures built with them.
