AS 1163 C350 hollow section is a type of structural steel that has gained significant popularity in the construction industry due to its unique properties and versatile applications. This Australian Standard (AS) specification defines the requirements for cold-formed structural steel hollow sections, with C350 indicating a minimum yield strength of 350 MPa. These hollow sections offer numerous advantages in terms of strength, durability, and design flexibility, making them an excellent choice for various structural applications.
What are the key features of AS 1163 C350 hollow sections?
AS 1163 C350 hollow sections are characterized by their high strength-to-weight ratio, making them an ideal choice for structural applications where weight is a critical factor. These sections are manufactured through a cold-forming process, which involves shaping steel at room temperature to create the desired hollow profile. This process results in improved mechanical properties compared to hot-formed sections.
The C350 grade designation indicates that the steel has a minimum yield strength of 350 MPa, providing excellent load-bearing capacity. This high strength allows for the use of smaller sections, reducing overall material consumption and project costs. Additionally, the hollow nature of these sections offers superior torsional rigidity compared to solid sections of similar weight.
AS 1163 C350 hollow sections are available in various shapes, including circular (CHS), rectangular (RHS), and square (SHS) profiles. This variety allows engineers and architects to choose the most suitable shape for their specific design requirements. The sections are typically manufactured from hot-rolled steel coils, ensuring consistent quality and dimensional accuracy.
One of the key features of AS 1163 C350 hollow sections is their excellent weldability. The steel composition and manufacturing process result in a material that can be easily welded using common welding techniques, facilitating efficient fabrication and assembly of structural components.
These hollow sections also offer superior corrosion resistance compared to many other structural steel products. The smooth surface finish and absence of sharp corners or crevices reduce the likelihood of corrosion initiation and progression. However, for enhanced protection in corrosive environments, additional surface treatments or coatings may be applied.
The versatility of AS 1163 C350 hollow sections extends to their aesthetic appeal. The clean lines and modern appearance of these sections make them popular choices for exposed structural elements in architectural designs. They can be easily integrated into various architectural styles, from industrial to contemporary.
In terms of fire resistance, AS 1163 C350 hollow sections perform well due to their closed profile. The hollow nature of these sections allows for the incorporation of fire-resistant materials within the cavity, further enhancing their fire performance without compromising the external appearance or structural integrity.
How does AS 1163 C350 hollow section compare to other structural steel options?
When comparing AS 1163 C350 hollow sections to other structural steel options, several key factors come into play. One of the primary advantages of these hollow sections is their exceptional strength-to-weight ratio. This characteristic sets them apart from traditional solid steel sections, such as I-beams or channels.
The high strength-to-weight ratio of AS 1163 C350 hollow sections allows for the use of lighter members without compromising structural integrity. This reduction in weight can lead to significant cost savings in several areas of a construction project. For instance, lighter structural members require less substantial foundations, reducing excavation and concrete costs. Additionally, the reduced weight of the overall structure can lead to savings in transportation and handling expenses.
Compared to solid sections, AS 1163 C350 hollow sections offer superior torsional rigidity. This property is particularly beneficial in applications where twisting forces are a concern, such as in long-span structures or members subjected to eccentric loading. The closed profile of hollow sections provides inherent resistance to torsional deformation, often eliminating the need for additional stiffening elements that might be required with open sections.
In terms of buckling resistance, AS 1163 C350 hollow sections generally outperform open sections of similar weight. The symmetrical nature of hollow sections, particularly in the case of circular hollow sections (CHS), provides uniform resistance to buckling in all directions. This characteristic can be especially advantageous in compression members or columns.
When it comes to wind and seismic loading, AS 1163 C350 hollow sections offer advantages due to their aerodynamic properties and high strength-to-weight ratio. Circular hollow sections, in particular, present less wind resistance compared to flat-sided sections, making them ideal for structures in high-wind areas. The lightweight nature of these sections also contributes to reduced seismic forces, as the overall mass of the structure is decreased.
In terms of fabrication and construction, AS 1163 C350 hollow sections often provide advantages over other steel options. The smooth, continuous surface of hollow sections simplifies connection design and execution. Welded connections can be made around the entire perimeter of the section, distributing stresses more evenly and potentially reducing the need for additional connection plates or stiffeners.
The closed profile of AS 1163 C350 hollow sections also offers practical benefits in terms of maintenance and durability. Unlike open sections that can accumulate dirt, debris, or moisture in flanges or web-flange intersections, hollow sections present a clean, easy-to-maintain surface. This characteristic can lead to reduced long-term maintenance costs and improved durability of the structure.
From an architectural perspective, AS 1163 C350 hollow sections often provide a more aesthetically pleasing appearance compared to traditional steel sections. The clean lines and modern look of hollow sections make them popular choices for exposed structural elements in contemporary architecture. This can eliminate the need for additional cladding or concealment of structural members, potentially reducing costs and simplifying the construction process.
However, it's important to note that the choice between AS 1163 C350 hollow sections and other structural steel options depends on the specific requirements of each project. Factors such as loading conditions, span lengths, architectural considerations, and local availability of materials all play a role in determining the most suitable structural solution. In some cases, a combination of different section types may provide the optimal solution for a given structure.
What are the common applications of AS 1163 C350 hollow sections in construction?
AS 1163 C350 hollow sections find widespread use in various construction applications due to their versatility, strength, and aesthetic appeal. These sections are employed in a diverse range of structures, from small-scale residential projects to large industrial and commercial developments.
One of the most common applications of AS 1163 C350 hollow sections is in the construction of steel-framed buildings. In this context, they are frequently used as columns, beams, and bracing members. The high strength-to-weight ratio of these sections allows for efficient structural designs, particularly in multi-story buildings where weight reduction is crucial. Circular hollow sections (CHS) are often preferred for columns due to their uniform buckling resistance in all directions, while rectangular (RHS) or square (SHS) hollow sections are commonly used for beams and bracing elements.
In industrial construction, AS 1163 C350 hollow sections play a vital role in the design and fabrication of equipment support structures, pipe racks, and conveyor systems. The closed profile of these sections provides excellent resistance to torsional loads, making them ideal for supporting rotating machinery or conveyor belts. Additionally, their smooth surface and lack of sharp corners facilitate easier cleaning and maintenance, which is particularly important in food processing or pharmaceutical facilities where hygiene is paramount.
The transportation infrastructure sector is another area where AS 1163 C350 hollow sections find extensive application. They are commonly used in the construction of bridges, particularly in pedestrian and cycle bridges where lightweight design is crucial. The sections are employed as main structural members, handrails, and balustrades. In larger bridge structures, hollow sections may be used for arch ribs, truss members, or as part of composite deck systems.
Sports and recreational facilities often incorporate AS 1163 C350 hollow sections in their design. These sections are frequently used in the construction of stadium roofs, grandstands, and supporting structures for large video screens or scoreboards. The high strength and good fatigue resistance of these sections make them suitable for structures subject to dynamic loads, such as those experienced in sports arenas.
In the energy sector, AS 1163 C350 hollow sections play a crucial role in the construction of transmission towers and wind turbine support structures. The high strength-to-weight ratio and excellent buckling resistance of these sections make them ideal for tall, slender structures subjected to wind and ice loads. Circular hollow sections, in particular, are often used in wind turbine towers due to their aerodynamic properties and uniform strength characteristics.
The agricultural industry also benefits from the use of AS 1163 C350 hollow sections. These sections are commonly employed in the construction of large-span structures such as barns, storage sheds, and greenhouses. The ability to create long-span structures with minimal intermediate supports makes hollow sections an attractive option for these applications, maximizing usable floor space and improving operational efficiency.
In urban environments, AS 1163 C350 hollow sections are increasingly being used in the design of street furniture and public art installations. Their clean lines and modern appearance make them popular choices for bus shelters, bicycle racks, and decorative structures. The durability and corrosion resistance of these sections ensure long-term performance in exposed outdoor conditions.
The marine and offshore industries also utilize AS 1163 C350 hollow sections in various applications. These sections are used in the construction of jetties, wharves, and offshore platforms. The excellent corrosion resistance of hollow sections, particularly when combined with appropriate protective coatings, makes them suitable for harsh marine environments.
In residential construction, while not as common as in commercial or industrial applications, AS 1163 C350 hollow sections are gaining popularity for specific uses. They are often employed in the design of modern, open-plan homes where long spans and minimal visual obstruction are desired. Hollow sections can be used as exposed structural elements, combining functionality with aesthetic appeal.
Lastly, AS 1163 C350 hollow sections find application in temporary structures and scaffolding systems. Their high strength-to-weight ratio and ease of assembly make them ideal for creating robust yet easily dismantled temporary structures for events, construction sites, or emergency response situations.
In conclusion, the advantages of AS 1163 C350 hollow sections, including their high strength, excellent torsional rigidity, and versatile profiles, make them a preferred choice for a wide range of construction applications. From towering skyscrapers to intricate architectural features, these hollow sections continue to play a crucial role in shaping the built environment, offering engineers and architects a powerful tool for creating efficient, durable, and aesthetically pleasing structures.
References
1. Standards Australia. (2016). AS 1163-2016: Structural steel hollow sections.
2. American Institute of Steel Construction. (2022). Steel Construction Manual, 15th Edition.
3. Wardenier, J., et al. (2010). Hollow Sections in Structural Applications. CIDECT.
4. Packer, J.A., et al. (2009). Design Guide for Rectangular Hollow Section (RHS) Joints Under Predominantly Static Loading. CIDECT.
5. European Committee for Standardization. (2005). Eurocode 3: Design of steel structures.
6. Zhao, X.L., et al. (2016). Cold-Formed Circular Steel Tubes and Pipes. CRC Press.
7. Kurobane, Y., et al. (2004). Design Guide for Structural Hollow Section Column Connections. CIDECT.
8. Tata Steel. (2021). Structural Hollow Sections Design Manual.
9. OneSteel. (2019). Structural Steel Hollow Sections: Product Guide.
10. Uy, B., et al. (2011). Composite Steel-Concrete Structures. Elsevier.
