GB/T 714-2000 Structural Steel for Bridges —Mechanical and Technological Properties
This standard mainly applies to hot-rolled structural steel plates, bars and shapes used in bridges. The general requirements and technical conditions of delivery for steel structural products are stipulated in GB/T 700.
This standard stipulates the mechanical properties and technological requirements of hot-rolled structural steel plates and bars used in bridges. In this standard, the steels are qualified according to different types and grades.
This standard stipulates that the steel should be of guaranteed quality, meeting the requirements of GB/T 700-1988. All steel should be provided by a quality guarantee agency approved by the state.
The types and grades of the steel stipulated in this standard are as follows:
1. Type I: high strength steel:
Q420, Q460, Q500, Q550, Q690 and other grades;
2. Type II: medium plate steel:
Q235, Q275 and other grades.
The mechanical properties of the steel should meet the requirements specified in table 1.
Table 1 Mechanical Properties of Structural Steel
Steel Type | Tensile Strength Re, MPa | Yield Strength Rp0.2, MPa | Elongation
Type I ≥440 ≥335 ≥18
Type II ≥375 ≥235 ≥21
This standard also stipulates the technological requirements of the steel products.
The surface quality of the steel should meet the requirements specified in table 2.
Table 2 Surface Quality Characteristics of Structural Steel
Defect | Quality
Slight corrosion and rust | Clean
Depression orifice | Clear
Surface delamination | Non-existent
Surface burrs | Non-existent
White rust | Non-existent
Welding slag | Non-existent
The thickness measurement of structural steel should meet the requirements specified in GB/T 228 and table 3.
Table 3 Thickness Measurement of Structural Steel
Thickness Range, mm | Tolerance Divergence
4 and below | 0%
Above 4 | 3%
The length of structural steel should be greater than 500mm and the length tolerance should be ±20mm.
The width of structural steel should be greater than 200mm and the width tolerance should be ±20mm.
The shape of structural steel should meet the requirements specified in GB/T 709-1988.
The steel bending performance and bending shape should meet the requirements of GB/T 2101-1989.
The steel heat treatment should meet the requirements specified in GB/T 4335-1991.
The steel surface protection should meet the requirements of GB/T 17107-1997.
The marking requirements and type characters of structural steel should meet the requirements of GB/T 709-1988.
In conclusion, GB/T 714-2000 Structural Steel for Bridges —Mechanical and Technological Properties specifies the different types of steel and their grades, mechanical properties, and technological requirements employed to construct steel bridges. This standard plays an important role in ensuring that the bridges built using these steels are safe and reliable structures under different loading and environmental conditions.
