Environmental Properties of Concrete
Concrete is in tune with the environment. From homes to office buildings to highways, using concrete as a construction material actually helps protect our natural resources and affords unique benefits to consumers. From an environmental standpoint, concrete has a lot to offer.
Concrete is environmentally friendly in a variety of ways. The ingredients of concrete (water, aggregate, and cement) are abundant in supply and take a lesser toll in their extraction than other construction materials. Quarries, the primary source of raw materials, can be easily reclaimed for recreational, residential, or commercial use. Or they can be restored to their natural state.
As a nearly inert material, concrete is an ideal medium for recycling waste or industrial byproducts. Many materials that would end up in landfills can be used instead to make concrete. Blast furnace slag, recycled polystyrene, and fly ash are among materials that can be included in the recipe for concrete and further enhance its appeal. Waste products such as scrap tires and kiln dust are used to fuel the manufacture of cement. Even old concrete itself can be reborn as aggregate for new concrete mixtures.
Another environmental plus for concrete is energy efficiency. From manufacture to transport to construction, concrete is modest in its energy needs and generous in its payback. The only energy intensive demand is in the manufacture of portland cement, typically a 10-15% component of concrete. Since the materials for concrete are so readily available, concrete products and ready-mixed concrete can be made from local resources and processed near a jobsite. Local shipping minimizes fuel requirements for handling and transportation.
Once in place, concrete offers significant energy savings over the lifetime of a building or pavement. In homes and buildings concrete’s thermal mass, bolstered by insulating materials, affords high R-factors and moderates temperature swings by storing and releasing energy needed for heating and cooling. Rigid concrete pavement design means heavy trucks consume less fuel. And the light reflective nature of concrete makes it less costly to illuminate. Also, pervious concrete pavements can reduce storm water run-off and help recharge our natural ground water.
Further commendable characteristics of concrete are waste minimization and long life. Whether it’s cast-in-place or pre-cast, concrete is used on an as-needed basis. Leftovers are easily reused or recycled. And concrete is a durable material that actually gains strength over time, conserving resources by reducing maintenance and the need for reconstruction.
A reliable and versatile product for centuries, concrete paves the way toward an environmentally secure future for successive generations here on Earth.
Information compliments of Environmental Council of Concrete Organizations