Brick

Brick
Andrewlister · Public domain · source
Name	Brick
Caption	Fired clay bricks in a stack
Type	Construction unit
Invented	Neolithic period
Inventor	Unknown
Materials	Clay, shale, concrete
Density	1600–2000 kg/m³
Standard sizes	See section

Brick is a small rectangular unit used in built structures and paved surfaces, formed from materials such as clay, shale, or concrete and hardened by drying, firing, or chemical curing. Bricks have been produced and employed across civilizations including Mesopotamia, Indus Valley civilization, Ancient Egypt, and Roman Empire, and remain fundamental to practices in contemporary architecture, civil engineering, and urban planning. Their standardized form supports repetitive modular construction methods used by firms, municipalities, and institutions worldwide.

History

Bricks appear in archaeological records from Jericho and Çatalhöyük in the Neolithic era, evolving through innovations credited to builders in Sumer and the Indus Valley civilization who used sun-dried and fired units in temples and fortifications. The Roman Empire advanced brickmaking with mass production, stamped standards, and integration into infrastructures like aqueducts and the Colosseum, influencing medieval techniques in Byzantium and Venice. During the Industrial Revolution, mechanization led by entrepreneurs in Britain and industrialists associated with Bessemer-era firms intensified production, aligning with the expansion of railways by companies such as the Great Western Railway and urbanization in cities like London and Manchester. Twentieth-century developments in the United States, Germany, and Japan introduced concrete block competition, while postwar reconstruction in Berlin and Warsaw relied heavily on brickwork for rapid rebuilding under municipal programs and international agencies like the United Nations Relief and Rehabilitation Administration.

Materials and Manufacturing

Traditional bricks are formed from clay or shale mined near sites like the Loess Plateau or the Rhone Valley, blended with water, shaped in molds, and dried. Firing in chambers evolved from primitive clamp kilns to continuous tunnel kilns and Hoffman kilns developed in Germany, reaching controlled temperatures for vitrification. Alternative materials include Portland cement mixtures used in concrete bricks produced in plants operated by companies such as Lafarge and Cemex, and calcium-silicate bricks by manufacturers tracing processes to innovations from institutions like the Royal Society of Arts. Additives and glazes incorporate minerals sourced from regions such as Cornwall and Upper Silesia. Quality control relies on standards promulgated by organizations including British Standards Institution and American Society of Civil Engineers.

Types and Properties

Brick types encompass common burned clay, facing brick, engineering brick, hollow brick, perforated brick, and sand-lime brick, each meeting performance criteria established in codes like those from the International Organization for Standardization and national bodies such as the American Concrete Institute. Properties include compressive strength, water absorption, thermal conductivity, and frost resistance, with data referenced in manuals from ASTM International and testing protocols used by laboratories at universities such as Massachusetts Institute of Technology and Imperial College London. Engineering bricks used in infrastructures commissioned by agencies like Network Rail are specified for high strength and low permeability; facing bricks selected for facades meet color and texture preferences driven by architects influenced by movements from Gothic Revival to Modernism.

Uses and Applications

Bricks serve in load-bearing walls, veneers, paving, chimneys, and ornamental features in projects overseen by entities including municipal authorities of New York City and preservation groups like English Heritage. In infrastructure, bricks are used in culverts, sewer linings, and bridge abutments managed historically by contractors for schemes such as the Panama Canal adjacent works and Victorian-era urban drainage in Manchester. Contemporary architects from firms like Foster + Partners and Herzog & de Meuron exploit brick for aesthetic cladding and thermal mass in residential developments commissioned by developers such as Habitat and governmental housing authorities.

Structural Design and Construction

Structural design with brick integrates bonding patterns—English bond, Flemish bond, stretcher bond—documented in textbooks used by students at University of Cambridge and practices adopted in projects by firms such as Skanska. Mortars composed of lime, cement, or polymer-modified binders are specified per standards by organizations including Building Research Establishment and applied by tradespeople trained in unions such as those affiliated with the International Union of Bricklayers. Lateral load resistance, shear transfer, and seismic detailing reference guidance from codes like those of the Eurocode and American Institute of Architects, while masonry engineers consult research from institutions including ETH Zurich for retrofitting strategies.

Conservation and Preservation

Conservation of historic brickwork involves analysis by conservationists associated with museums such as the Victoria and Albert Museum and agencies including ICOMOS and Historic England. Techniques include matching original clay sources, employing traditional lime mortars used in restorations of monuments like St Paul's Cathedral and Hagia Sophia, and addressing salt crystallization and spalling documented in conservation reports prepared by laboratories at English Heritage and university centers like Delft University of Technology. Interventions balance authenticity principles set out by the Venice Charter and modern requirements for thermal upgrading pursued in retrofit projects supported by programs from the European Commission.

Category:Building materials Category:Masonry