I-beam

As the name implies, I-beam is a kind of "I"-shaped cross-section steel. Its processing method can be hot rolling or cold drawing. It is one of the common building materials. The inner surface of the upper and lower flanges has a slope, generally 1:6, making The flange is thin on the outside and thick on the inside. Therefore, the cross-sectional properties of the I-beam on the two main planes are greatly different, making it difficult to exert the strength properties of the steel in application. Although thickened I-beams have also appeared on the I-beam market, the structure of the I-beam has determined its shortcomings in torsional performance.

I-beams are mainly divided into ordinary I-beams, light I-beams and wide-flange I-beams. According to the height ratio of flange to web, it is divided into wide, medium and narrow wide flange I-beams. The first two are produced in sizes 10 to 60, which means the corresponding height is 10 to 60cm. At the same height, lightweight I-beams have narrow flanges, thin webs, and light weight. Wide-flange I-beam is also called H-shaped steel. The cross-section feature is that the legs are parallel and there is no slope on the inside of the legs.

Installation steps of I-beam

1. Measurement

Before installing the I-beam, it is necessary to measure and accurately measure the length, width, height, etc. of the I-beam to avoid errors during the installation process. In particular, steel girders need to be installed with a flat bottom to avoid wobbling or instability.

2. Cushion

Before installing the I-beam, the bottom of the steel beam needs to be cushioned to increase its stability. The material of the cushion can be wood board or other hard materials. Make sure that the thickness of the cushion is the same and the bottom is flat to avoid deformation of the steel beam.

3. Fixed

After the I-beam is placed in the predetermined position, it needs to be fixed. The most commonly used method is to use bolts and nuts for fastening, and the bolts and nuts should be evenly distributed on the surface of the I-beam so that the force is relatively balanced. After the fixation is completed, mechanical calculations are required to ensure that it can withstand the predetermined weight and pressure.

4. Auxiliary equipment

In addition to the above operations, the use of some auxiliary equipment also needs to be considered. For example, shock pads, rubber pads, or other cushioning materials can be used to relieve the pressure between the building and the steel beams. In addition, it is also possible to add a closed design to the steel beam to increase its safety and service life.

Advantages of I-beam installation

1. Good stability

After installation, the I-beam can provide better stability and load-bearing capacity. Its shape and structure can effectively reduce the internal compression and displacement of the building and maintain the stability of the building.

2. Low maintenance cost

Due to the high stability and durability of I-beams, maintenance costs are relatively low. In long-term use, it is not prone to deformation or damage, saving the cost of later maintenance and replacement.

3. Convenient construction

During the construction process, I-beams can usually be prefabricated, making their installation relatively convenient. Its flexibility and plasticity are relatively high, and it can be processed and installed according to different shapes of buildings.

4. Wide range of application

I-beams have a wide range of applications, not only for load-bearing and support of buildings, but also for the construction of large-scale projects such as bridges and tunnels. In industrial manufacturing, it can also be used to bear the weight of heavy equipment and machines.

The installation of I-beams is a complex process that requires consideration of various factors to ensure its stability and load-bearing capacity. During the installation process, you need to pay attention to selecting appropriate materials, using correct fixing methods, and processing and installing I-beams quickly and reliably to prevent potential safety hazards. I-beams provide a wider range of applications and better properties, becoming one of the important building materials in construction engineering and industrial manufacturing.

In China, the standards for I-beams and other structural steel sections are established by the Chinese National Standards (GB) or the Chinese National Building Codes (GB/T). The most commonly used I-beam in China is known as the "I-shaped cross-section hot-rolled steel" or simply "I-beam."

The specifications and designations for I-beams in China are covered under various GB standards, depending on the specific requirements and applications. The primary standard that outlines the dimensions, technical requirements, and tolerances for I-beams is GB/T 706-2016.

The designation of I-beams in China follows a standard format that includes the height (web height), flange width, flange thickness, and web thickness. For example, an I-beam with the designation "I 200 x 100 x 5.6 x 8" would have a height of 200 mm, a flange width of 100 mm, a flange thickness of 5.6 mm, and a web thickness of 8 mm.

In addition to GB/T 706-2016, there are other GB standards that cover various aspects of steel sections, including GB/T 1591 for high-strength low-alloy structural steels and GB/T 11263 for hot-rolled H and I sections.

In the United States, the standards for I-beams are governed by the American Society for Testing and Materials (ASTM) and the American Institute of Steel Construction (AISC). These organizations establish specifications and guidelines for the design, manufacturing, and use of structural steel, including I-beams.

The most common type of I-beam used in the US is known as the Wide Flange (WF) or W-beam. The specifications for W-beams are outlined in ASTM A992/A992M, which covers structural shapes produced from steel with a minimum yield strength of 50 ksi (kips per square inch) or 345 MPa (megapascals). ASTM A992/A992M replaced the older ASTM A36 standard, which was a common material for W-beams but has been largely phased out due to the higher strength and more economical A992 steel.

The designations of W-beams follow a standard naming convention based on their dimensions. For example, a W10x22 beam would have a depth of 10 inches and weigh 22 pounds per foot. The first number (in this case, 10) represents the nominal depth, while the second number (22) indicates the weight per linear foot.

Apart from W-beams, there are also S-beams (American Standard Beams or S-shapes) and M-beams (American Standard Junior Beams or M-shapes) that are used less frequently in modern construction. The specifications for these beams can be found in ASTM A6/A6M.

In the United Kingdom, the standards for I-beams, and other structural steel sections, are set by the British Standards Institution (BSI). The commonly used I-beam in the UK is referred to as an "Universal Beam" (UB) or "Rolled Steel Joist" (RSJ). The specifications and designations for these beams are outlined in the British Standard BS EN 10365.

BS EN 10365 covers a wide range of hot-rolled steel sections used in various construction and engineering applications. This standard specifies the dimensions, technical requirements, and tolerances for UBs, which are I-shaped structural steel beams with parallel flanges.

The designation of Universal Beams follows a standard format that includes the beam's depth (in millimeters) and its mass per meter (in kilograms). For example, a UB 305 x 165 x 46 would have a depth of 305 mm, a flange width of 165 mm, and a mass of 46 kg per meter.

In addition to Universal Beams, there are also "Universal Columns" (UC), which are H-shaped sections, and "Parallel Flange Channels" (PFC) that are also covered under BS EN 10365.

BS EN 10365 was introduced to replace the previous British Standard for structural steel sections, BS 4. It aligns with European standards (Eurocodes) and facilitates harmonization across different European countries.

In Japan, the standards for I-beams, as well as other structural steel sections, are established by the Japanese Industrial Standards (JIS). The commonly used I-beam in Japan is known as the "Wide Flange Shape" or "H-Beam."

The specifications and designations for H-beams are outlined in the JIS G 3192 standard, which covers the dimensions, sectional properties, and technical requirements for hot-rolled steel sections used in general structures.

H-beams in Japan are identified by their dimensions, including the height (web height), width (flange width), and flange thickness. The designation format includes four numbers: the first two numbers represent the height in millimeters, the third number indicates the width in millimeters, and the fourth number signifies the flange thickness in millimeters. For example, an H-beam with the designation "H 250 x 125 x 6 x 9" would have a height of 250 mm, a width of 125 mm, a flange thickness of 6 mm, and a web thickness of 9 mm.

The allowable deviation of the average leg thickness of I-beam is ±0.06t.

The bending deflection of the I-beam should not exceed 0.15d.

The outer edge slope of the I-beam legs shall not be greater than 1.5%b for one leg and 2.5% for both legs.

The passivation of I-beam leg ends and shoulders shall not allow round bars with a diameter equal to 0.18t to pass through.

Shape:

1. Curvature. The bending degree of I-beam is not more than 2mm per meter. The total bending degree is not more than 0.2% of the total length.

2. Twist. The I-beam shall not have obvious torsion.