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The argument over what material to use in new building construction usually centers around the choice of either concrete or steel. Which is the better material? The answer is usually dependant on the type of building and its intended use. Both provide for many advantages and benefits.
The first consideration is one of safety. The building core of a concrete building is very safe. Cast-in-place concrete offers outstanding protection against any impact. It can also endure fire for a long time without any loss to its structural integrity. There is no need for additional fireproofing of concrete to meet fire codes. The mass and strength of concrete also provides for high wind protection, The proper design of a concrete building can also help with any seismic concerns. Steel design and construction now can include spray-on fireproofing which enhances the natural non-combustibility of steel. Steel’s strength, along with professional engineering and design, also make it a material of choice for active seismic zones. Steel framed buildings also perform well under high wind conditions. Steel can bend without breaking in the most adverse of wind conditions and absorb the energy without any negative effects.
The second consideration in the choice of materials is the cost. The price of ready-mix concrete remains relatively stable. However, the cost of cast-in-place concrete construction can be pricey on the front end. This is offset by possible reduced building insurance premiums because of concrete’s increased safety and structural integrity. Although steel, in recent years, has seen increased prices, structural steel still only represents only 20 percent of all of the steel used in building construction. Project costs in the most recent years have gone up about 10%, but that is in large part due to the increase in costs in every construction material, not just steel. Sturdy I-Beam construction represents less than 2% of this 10% increase in costs. Compared to steel, concrete costs have gone up pretty much equivalently.
The availability of materials is another factor. Shortages of cement, the primary binding element for concrete, have been reported across the United States, especially in the aftermath of recent hurricanes. Shipping rates and a limited number of transportation ships have also contributed to shortages. This has resulted in higher costs and unreliable supplies of concrete. The availability of steel has been questioned in recent years, primarily due to the explosive growth of the Chinese economy. Shortages now, however, are lessening. There is now adequate capacity to meet any growth in structural steel needs in the near future.
The final consideration is the design possibilities of both materials. Concrete can, basically, take on any shape or form. Cast-in-place concrete for use in a high rise office building can yield more rental space because of lower floor-to-floor heights. Steel, on the other hand, has the highest strength-to-weight ratio of any construction material. Clear span steel construction is available to provide wide areas of space without the need for interior load-bearing columns.
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