Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined.
A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Concrete is the most widely used material in existence and is behind only water as the planet's most-consumed resource.
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentary and erosive geological processes; it is also produced in large quantities commercially as crushed stone.
A road surface or pavement is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, hoggin, cobblestone and granite setts were extensively used, but these have mostly been replaced by asphalt or concrete laid on a compacted base course. Asphalt mixtures have been used in pavement construction since the beginning of the 20th century and are of two types: metalled (hard-surfaced) and unmetalled roads. Metalled roadways are made to sustain vehicular load and so are usually made on frequently used roads. Unmetalled roads, also known as gravel roads or dirt roads, are rough and can sustain less weight. Road surfaces are frequently marked to guide traffic.
The general term slag may be a by-product or co-product of smelting (pyrometallurgical) ores and recycled metals depending on the type of material being produced. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be classified as ferrous, ferroalloy or non-ferrous/base metals. Within these general categories, slags can be further categorized by their precursor and processing conditions. Slag generated from the EAF process can contain toxic metals, which can be hazardous to human and environmental health.
Asphalt concrete is a composite material commonly used to surface roads, parking lots, airports, and the core of embankment dams. Asphalt mixtures have been used in pavement construction since the beginning of the twentieth century. It consists of mineral aggregate bound together with bitumen, laid in layers, and compacted.
Vulcan Materials Company is an American company based in Birmingham, Alabama. It is principally engaged in the production, distribution and sale of construction materials. Vulcan is the largest producer of construction materials, primarily gravel, crushed stone, and sand, and employs approximately 12,000 people at over 400 facilities. Vulcan serves 22 states, the District of Columbia, Mexico, Canada, Bahamas and the U.S. Virgin Islands. Vulcan's innovative Crescent Market project led to construction of a large quarry and deep water seaport on the Yucatán Peninsula of Mexico, just south of Cancun. This quarry supplies Tampa, New Orleans, Houston, and Brownsville, Texas, as well as other Gulf coast seaports, with crushed limestone via large 62,000-ton self-discharging ships.
Glass recycling is the processing of waste glass into usable products. Glass that is crushed or imploded and ready to be remelted is called cullet. There are two types of cullet: internal and external. Internal cullet is composed of defective products detected and rejected by a quality control process during the industrial process of glass manufacturing, transition phases of product changes and production offcuts. External cullet is waste glass that has been collected or reprocessed with the purpose of recycling. External cullet is classified as waste. The word "cullet", when used in the context of end-of-waste, will always refer to external cullet.
Concrete recycling is the use of rubble from demolished concrete structures. Recycling is cheaper and more ecological than trucking rubble to a landfill. Crushed rubble can be used for road gravel, revetments, retaining walls, landscaping gravel, or raw material for new concrete. Large pieces can be used as bricks or slabs, or incorporated with new concrete into structures, a material called urbanite.
Cement clinker is a solid material produced in the manufacture of portland cement as an intermediary product. Clinker occurs as lumps or nodules, usually 3 millimetres (0.12 in) to 25 millimetres (0.98 in) in diameter. It is produced by sintering limestone and aluminosilicate materials such as clay during the cement kiln stage.
Graniterock is an American corporation, founded in 1900 as "Granite Rock", and based in Watsonville, California. It operates in the construction industry providing crushed gravel, sand, concrete, asphalt and paving services.
Crushed stone or angular rock is a form of construction aggregate, typically produced by mining a suitable rock deposit and breaking the removed rock down to the desired size using crushers. It is distinct from naturally occurring gravel, which is produced by natural processes of weathering and erosion and typically has a more rounded shape.
A concrete plant, also known as a batch plant or batching plant or a concrete batching plant, is equipment that combines various ingredients to form concrete. Some of these inputs include water, air, admixtures, sand, aggregate, fly ash, silica fume, slag, and cement. A concrete plant can have a variety of parts and accessories, including: mixers, cement batchers, aggregate batchers, conveyors, radial stackers, aggregate bins, cement bins, heaters, chillers, cement silos, batch plant controls, and dust collectors.
Copper slag is a by-product of copper extraction by smelting. During smelting, impurities become slag which floats on the molten metal. Slag that is quenched in water produces angular granules which are disposed of as waste or utilized as discussed below.
The Mineral Products Association (MPA) is the United Kingdom trade association for the aggregates, asphalt, cement, concrete, dimension stone, lime, mortar, and silica sand industries.
Recycling can be carried out on various raw materials. Recycling is an important part of creating more sustainable economies, reducing the cost and environmental impact of raw materials. Not all materials are easily recycled, and processing recyclable into the correct waste stream requires considerable energy. Some particular manufactured goods are not easily separated, unless specially process therefore have unique product-based recycling processes.
Breedon Group plc is a British construction materials company which has its headquarters at Breedon on the Hill, Leicestershire, England. It is listed on the London Stock Exchange and is a constituent of the FTSE 250 Index.
Oldcastle Materials Inc. is a supplier of asphalt, concrete, and other building materials, and also offers construction and paving services. The Atlanta-based company is a subsidiary of CRH plc, a publicly traded international group of diversified building materials businesses, and has approximately 18,000 employees at 1,200 locations, as of March 2018.
In 2017, the aggregate industry in the United States mined and sold 2.12 billion metric tons of crushed rock, sand and gravel valued at US$20.9 billion. There are thousands of aggregate-producing companies in the US, operating in each of the 50 states, and employing 105,000 people. Most aggregate is used by the construction industry, where it is an essential raw material and the main ingredient in concrete and asphalt concrete.
The Antoing cement kiln is in the Belgian province of Hainaut. The facility is next to the Scheldt River in the Tournai region. It was built in 1929 under CBR which was later taken over by Heidelberg Materials.
