Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement that hardens (cures) 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 aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is being done to try to reduce the emissions or make concrete a source of carbon sequestration, and increase recycled and secondary raw materials content into the mix to achieve a circular economy. Concrete is expected to be a key material for structures resilient to climate disasters, as well as a solution to mitigate the pollution of other industries, capturing wastes such as coal fly ash or bauxite tailings and residue.
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, building stone such as marble, granite, and limestone, cast stone, concrete block, glass block, and adobe. Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern in which the units are assembled can substantially affect the durability of the overall masonry construction. A person who constructs masonry is called a mason or bricklayer. These are both classified as construction trades.
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion.
A floor is the bottom surface of a room or vehicle. Floors vary from simple dirt in a cave to many-layered surfaces made with modern technology. Floors may be stone, wood, bamboo, metal or any other material that can support the expected load.
Prestressed concrete is a form of concrete used in construction. It is substantially "prestressed" (compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service.
A concrete slab is a common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete. Steel-reinforced slabs, typically between 100 and 500 mm thick, are most often used to construct floors and ceilings, while thinner mud slabs may be used for exterior paving (see below).
Steel frame is a building technique with a "skeleton frame" of vertical steel columns and horizontal I-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame. The development of this technique made the construction of the skyscraper possible.
Formwork is molds into which concrete or similar materials are either precast or cast-in-place. In the context of concrete construction, the falsework supports the shuttering molds. In specialty applications formwork may be permanently incorporated into the final structure, adding insulation or helping reinforce the finished structure.
Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a profile of a specific cross section. Structural steel shapes, sizes, chemical composition, mechanical properties such as strengths, storage practices, etc., are regulated by standards in most industrialized countries.
A countertop, also counter top, counter, benchtop, worktop or kitchen bench, Bunker (Scottish) is a raised, firm, flat, and horizontal surface. They are built for work in kitchens or other food preparation areas, bathrooms or lavatories, and workrooms in general. The surface is frequently installed upon and supported by cabinets, positioned at an ergonomic height for the user and the particular task for which it is designed. A countertop may be constructed of various materials with different attributes of functionality, durability and aesthetics, and may have built-in appliances, or accessory items relative to the intended application.
Hollow-core is a type of precast, prestressed concrete floor slab. It is often used in construction of multi-storey buildings. The advantages it has over cast-in-place concrete floor are that it is lighter in weight and often cheaper. Also, wet concrete needs to be pumped or carried up to higher floors. The slabs which are manufactured off site are simply lifted with a crane and set in place. Disadvantages are an increased overall floor thickness, the cost of a steel frame over the cost of concrete columns and increased cranage requirements.
Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site and maneuvered into place; examples include precast beams, and wall panels for tilt up construction. In contrast, cast-in-place concrete is poured into site-specific forms and cured on site.
A shallow foundation is a type of building foundation that transfers structural load to the earth very near to the surface, rather than to a subsurface layer or a range of depths, as does a deep foundation. Customarily, a shallow foundation is considered as such when the width of the entire foundation is greater than its depth. In comparison to deep foundations, shallow foundations are less technical, thus making them more economical and the most widely used for relatively light structures.
Voided biaxial slabs, sometimes called biaxial slabs or voided slabs, are a type of reinforced concrete slab which incorporates air-filled voids to reduce the volume of concrete required. These voids enable cheaper construction and less environmental impact. Another major benefit of the system is its reduction in slab weight compared with regular solid decks. Up to 50% of the slab volume may be removed in voids, resulting in less load on structural members. This also allows increased weight and/or span, since the self-weight of the slab contributes less to the overall load.
Spancrete is an American manufacturer of precast concrete products and machinery. Spancrete produces precast, prestressed concrete products that are used in commercial, industrial, institutional, residential and multifamily construction projects in the Midwest and Southeast. The company also manufactures and sells hollowcore extrusion machines that are used to produce precast concrete internationally.
The Filigree Wideslab method is a process for construction of concrete floor decks from two interconnected concrete placements, one precast in a factory, and the other done in the field. The method was developed during the late 1960s by Harry H. Wise as a more efficient and economic construction process than conventional cast-in-place technologies.
Structural clay tile describes a category of burned-clay building materials used to construct roofing, walls, and flooring for structural and non-structural purposes, especially in fireproofing applications. Also called building tile, structural terra cotta, hollow tile, and clay block, the material is an extruded clay shape with substantial depth that allows it to be laid in the same manner as other clay or concrete masonry. In North America it was chiefly used during the late 19th and early 20th centuries, reaching peak popularity at the turn of the century and declining around the 1950s. Structural clay tile grew in popularity in the end of the nineteenth-century because it could be constructed faster, was lighter, and required simpler flat falsework than earlier brick vaulting construction. Each unit is generally made of clay or terra-cotta with hollow cavities, or cells, inside it. The material is commonly used in floor arches, fireproofing, partition walls, and furring. It continues to be used in Europe to build fire-resistant walls and partitions. In North America the material has largely been replaced by concrete masonry units.
A double tee or double-T beam is a load-bearing structure that resembles two T-beams connected to each other side by side. The strong bond of the flange and the two webs creates a structure that is capable of withstanding high loads while having a long span. The typical sizes of double tees are up to 15 feet (4.6 m) for flange width, up to 5 feet (1.5 m) for web depth, and up to 80 feet (24 m) or more for span length. Double tees are pre-manufactured from prestressed concrete which allows construction time to be shortened.
A waffle slab or two-way joist slab is a concrete slab made of reinforced concrete with concrete ribs running in two directions on its underside. The name waffle comes from the grid pattern created by the reinforcing ribs. Waffle slabs are preferred for spans greater than 40 feet (12 m), as they are much stronger than flat slabs, flat slabs with drop panels, two-way slabs, one-way slabs, and one-way joist slabs.
