The selection of structural steel for a building’s framing system brings numerous benefits to a project. All other materials are measured against the standard of structural steel and structural steel is still the material of choice. These benefits include:
Speed of Construction
Other materials may be able to start field work sooner, but the rapid design, fabrication and erection cycle with structural steel will allow the framing system to finish sooner and be available earlier to other trades.
Structural steel enhances construction productivity because of its shop fabrication while maintaining tight construction tolerances. Field placed material will always lag behind the productivity curve. Productivity enhancements for construction will occur not in labor based field activities, but in shop based technology enhancements.
Technology exists today in the form of 3-D interoperability and Building Information Modeling to allow the close cooperation between designers and steel specialty contractors in the design, fabrication and erection of building structures. This technology allows designs to save both time and dollars in the construction process by integrating fabricating and erection efficiencies in the design and passing design models between analysis, detailing and fabricating operations. This is full integration is process unique to structural steel generating significant cost savings.
Rapid erection in all seasons with close tolerances being maintained for integration with other building systems and minimal construction site waste is achievable only with structural steel.
Other materials may be able to start field work sooner, but the rapid design, fabrication and erection cycle with structural steel will allow the framing system to finish sooner and be available earlier to other trades.
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Lower Project Costs
Today, when competing framing systems are evaluated for projects using comparable, current cost data, structural steel remains the cost leader for the majority of construction projects. Comparative studies indicate that a structural steel framing system including decking and fire protection will typically cost 5% to 7% less than a concrete framing system on a national basis.
And that is not surprising; structural steel has remained the cost leader for construction materials over the past 30+ years. According to the Bureau of Labor Statistics the price for fabricated structural steel prices for commercial buildings increased 62% from their base date of 1980. In contrast, ready-mix concrete prices have escalated 114% during that same period. Why the difference? In 1980, 10 man-hours were required to produce a single ton of steel. Today that same ton of structural steel requires substantially less than a single man-hour. While not as dramatic, similar productivity enhancements have impacted the cost of detailing and fabrication. The end result is that the structural steel component of the construction industry is one of the few segments where significant productivity increases have occurred.
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Aesthetic Appeal
Architects praise the natural beauty of steel and are excited about exposing it in the design of their structures to emphasize grace, slenderness, strength and transparency of frame.
Structural steel allows the project architect a greater degree of expression and creativity in their design than any other construction material as they address both the functional demands of the building and unique identity of their client. Architects praise the natural beauty of steel and are excited about exposing it in the design of their structures to emphasize grace, slenderness, strength and transparency of frame. Column-free clear spans, the use of colored coatings and the opportunity for natural lighting highlight the elegant simplicity of using structural steel.
Structural steel sections can be bent and rolled to create non-linear members to further enhance the aesthetic appeal of the structure.
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Design Flexibility
From the simplest, functional structure to the complex, signature design structural steel can be readily used to accomplish the design intent of the architect and structural engineer. No other framing material comes close to structural steel in the ability to encourage freedom of expression and design creativity.
AISC annually sponsors the IDEAS2 (Innovative Design in Engineering and Architecture with Structural Steel) competition drawing entries from throughout the United States of recently completed structural steel projects. The range of submissions highlight the innovation and creative of project architects and structural engineers in their use of structural steel.
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High Strength
All other materials talk about high strength, but their strength is still less than that of structural steel even when enhanced by steel reinforcing. In fact, the increase in the standard strength of steel used in buildings today compared to 10 years ago is greater than the total strength of competing “high strength” materials. Structural steel is typically 50 ksi material indicating that the steel has a yield stress of 50,000 pounds per square inch in both compression and tension. By comparison, a normal concrete mix has a yield stress of 3 to 5 ksi in compression only and “high strength” concrete may have a compressive yield stress of 12 to 15 ksi. Not only is structural steel a stronger material, it also has a much higher strength to weight ratio than other materials. This results in the building being lighter and lighter buildings require less extensive and costly foundations.