With the variety of finishes available, including stains and integral color, various textures, such as acid-wash or aggregate, and different stamped patterns, concrete is one of the most versatile materials available today. Concrete is used outdoors for patios, driveways, walkways, freestanding walls and retaining walls, as well as outdoor kitchen countertops. Pre-cast concrete products are also abundant from concrete block to concrete pavers. Indoors, concrete is used for floors, countertops, even sinks. Depending on the type of finish or use of color, concrete can be a more cost effective material than others on the market thus the popularity of concrete in the building community.
Concrete is composed of cement, and other cementitious materials like fly ash and slag cement along with a course aggregate and sand, a fine aggregate. Today, concrete is the most widely used man-made construction material. The use of concrete in building dates back to the Roman era and showcases concrete’s strength and durability as many Roman structures have survived relatively intact through present time.
Beyond the components listed above, concrete can contain other ingredients such as admixtures or increased percentages of the original components to improve its properties for certain building applications. The addition of other ingredients was popular even during Roman times. Romans added different materials such as horsehair to reduce cracking while drying and blood to make concrete more frost-resistant. Today, there are different additives, or chemical admixtures, added to the concrete mix depending on the application. These additions improve the concrete’s properties, such as increasing the strength or electrical conductivity of the concrete. Additionally, you might hear concrete contractors talk about a five sack mix or six sack mix which refers to the amount of cement in a concrete mix. A different mix of concrete will be used to pour a driveway versus pour a water surrounded footing for a bridge.
Due to more stringent environmental regulations, concrete is becoming a more green building material through the use of recycled products. Mentioned above, fly ash, a by-product of coal fired power plants, acts like cement thus reducing the amount of quarrying and landfill space required as well as the amount of carbon dioxide emissions. Cement production produces a large amount of carbon dioxide so the use of fly ash and other similar materials will help cut emissions.