In its simplest form, concrete is a mixture of paste and aggregates (sand and rock). The paste, composed of Portland cement and water, coats the surface of the fine (sand) and coarse (rock) aggregates. Through a chemical reaction called hydration, the cement paste hardens and binds the aggregates together into a rock-like mass that is known as concrete.
Concrete is one of the most versatile building materials known to man. It can be used for roads, foundations, high rise skyscrapers, bridges, sidewalks, parking lots, residential housing, and a myriad of other applications. Fresh concrete can be molded or formed into any shape allowing decorative or architectural expression. It can be colored or stained, stamped or imprinted, and even used for beautiful kitchen countertops. Concrete is cost-effective, durable, and is made from abundant natural resources, which are completely recyclable.
Unlike many other building products, recycling is present from the beginning with concrete. Many wastes and industrial byproducts like ash and furnace slag that would otherwise clog landfills, can be added to concrete mixes. These byproducts also reduce reliance on raw materials. For example, in 2001, the concrete industry used 121,499,000 metric tons of fly ash -a byproduct of coal combustion at electric power utility plants. When concrete's lengthy service life is over, it can be recycled for a number of different uses.
A pothole is typically caused by either improper sub-grade preparation during the construction phase or by water penetrating through or under the concrete and eroding the sub-grade.
Concrete has been used as a building material for thousands of years. The Parthenon and other ancient buildings (still standing) in Greece were built with concrete. The Romans' use of concrete was also extensive. They built some 5,300 miles of roads for the use of their armies and traders using a primitive concrete mix. As well as utilizing concrete in the construction of their aqua duct system, bringing fresh water to many villages. Closer to home, roads built over 100 years ago in the United States are still in service.
Cement, aggregates (stone and sand) and water, and if needed admixtures are mixed together and loaded into concrete mixer trucks for jobsite delivery.
Absolutely! Concrete producers follow stringent guidelines set by the Environmental Protection Agency (EPA) and the Michigan Department of Environment, Great Lakes, and Energy (EGLE) to ensure that no air, water, or other environmental pollution occurs. They are subject to both voluntary and regulatory inspections to verify that they meet or exceed all current regulations.
Fresh concrete is a perishable product, having a relatively short time frame between when the water is added to the mix and delivery on the jobsite before hardening. As one of the most widely used building products, concrete plants must be located close to work sites.
In either a pliable or hardened state, concrete can easily be removed if an accidental spill occurs. Concrete quickly becomes inert and will not travel or penetrate the ground or cause the need for any soil remediation. However, due to the chemical reaction with the natural cement and aggregate products during the hardening process, care should be taken not to touch workable concrete without proper rubber gloves or boots as chemical burns may occur. If a concrete spill should occur, there is no environmental hazard that would affect water or other natural resources.
Since concrete is formulated from primarily natural products, there are little or no environmental hazards from the raw materials. Fuel and admixture storage are regulated by the EPA and the EGLE and must be contained by berms or other methods that would catch the contents in the event of an accidental spill.