The debate over whether steel or concrete is the better building material from a cost and safety factor is still continuing. Before modern engineering and the technological advances in concrete and steel construction the building systems favored were wood and brick. The materials that head the list of construction development today, however, are steel and concrete. Both materials provide numerous benefits.
Start with the factor of safety as accords concrete construction. The development of concrete for use in the new World Trade Center project in New York City makes a strong argument for the safety of concrete. There will be two foot thick concrete for protection of the inner core of the building against terrorist attack or fire. Reinforced concrete is very resistant to explosion and impact. Concrete can also endure high temperatures from fire for a long time without the loss of structural integrity. Concrete’s inherent mass and strength can also resist extreme hurricane force winds. The proper design and construction of concrete is also very resistant to seismic activity.
The addition of passive fire protection, such as spray-on fireproofing, can help buildings made of structural steel to sustain greater fire temperatures and provide additional safety to the building. Safety is taken into account with very effective designing and implementation of steel. Steel’s strength and ductility, combined with proper engineering and design and precise fabrication processes, make it a good choice for areas with seismic activity. Steel framing also performs very well under high wind conditions because of its propensity to bend but not to break.
The costs of these two superior building materials can also be compared. The price of concrete has become relatively stable. This is despite the spike seen in the costs of other building materials. Cast-in-place concrete can be pricier on the front end of a building project but the return on investment on the back end of the project can lessen the cost differential. Insurance costs can also be lower because insurance companies favor cast-in-place reinforced concrete which offers increased safety and structural integrity, thus reducing insurance premiums, in many cases. Some cast in place reinforced concrete structures can save over 20% annually on property insurance.
Structural steel has seen increases in prices over the last few years. But structural steel still only represents less than 20% of all the steel used in building construction. Looking at the overall impact on building project costs, the project costs have gone up by 10% as a result of increases in all types of construction materials-not just steel. The increase in cost of the steel structural framing system represents less than 2% of the 10% increase in project costs. Costs are almost a wash. The costs for a concrete framing system have gone up to equivalence to the costs of a steel framing system.