Steel and concrete are two of the most dominant building construction materials. Concrete can provide a solid foundation for the weight of the building and steel can hold taller structures up. Steel can help builders create structures with more complex designs. However, advances in technology have reduced a lot of the differences between these building materials.
Reinforced concrete is safer than steel and can resist explosions and high impact. Concrete can also handle high temperatures for a longer time than steel. Steel needs fireproofing to protect it from fires, or else the fire can weaken the steel structure and cause it to collapse. Because of this, some building codes do not let owners build steel structures without adequate concrete support, especially in densely populated areas. The weight of concrete allows it to resist high winds better than steel. However, concrete buildings are only as sturdy as their designs allow. A steel building can be sturdier than a concrete building if designed correctly. Steel structures designed with redundancy -- more support beams than required -- can remain standing if a portion of the building's support has weakened. Steel also can resist high winds because the material can bend.
While cast-in-place concrete can be very expensive, owners will often save money because insurance companies lower premiums, knowing that this kind of concrete offers greater safety. Insurance premiums for steel structures are higher because steel resists fire less effectively. Structural steel prices have remained stable because of low demand for steel in both the EU and the US (as of February 2011), though raw-material prices might drive the steel prices up, according to Steel On the Net. If the Chinese economic bubble bursts, steel prices could drop more. However, regular steel and concrete support systems cost roughly the same.
Steel structures can take longer to build than concrete structures. However, construction contractors save time by fabricating steel structures off-site. Also, advances in steel fabrication have hastened the steel construction process.
Steel buildings offer greater design flexibility than concrete buildings because the weight and strength of the steel allow the contractors to form different shapes, while the concrete has little flexibility and a lot of weight. However, concrete and steel are often used together to make the structure more sturdy. Builders can also create steel with longer spans than with concrete, which expands the construction possibilities.