Precast Concrete
Content
Precast concrete
A precast concrete walled house in construction 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 lifted into place. In contrast, standard concrete is poured into site-specific forms and cured on site. Precast stone is distinguished from precast concrete by using a fine aggregate in the mixture, so the final product approaches the appearance of naturally occurring rock or stone. By producing precast concrete in a controlled environment (typically referred to as a precast plant), the precast concrete is afforded the opportunity to properly cure and be closely monitored by plant employees. Utilizing a Precast Concrete system offers many potential advantages over site casting of concrete. The production process for Precast Concrete is performed on ground level, which helps with safety throughout a project. There is a greater control of the quality of materials and workmanship in a precast plant rather than on a construction site. Financially, the forms used in a precast plant may be reused hundreds to thousands of times before they have to be replaced, which allows cost of formwork per unit to be lower than for site-cast production. Many states across the United States require a precast plant to be certified by either the Architectural Precast Association (APA), National Precast Concrete Association (NPCA) or Precast Prestressed Concrete Institute (PCI) for a precast producer to supply their product to a construction site sponsored by State and Federal DOTs. There are many different types of precast concrete forming systems for architectural applications, differing in size, function, and cost. Precast architectural panels are also used to clad all or part of a building facade free-standing walls used for landscaping, soundproofing, and security walls, and some can be Prestressed concrete structural elements. Stormwater drainage, water and sewage pipes, and tunnels make use of precast concrete units. The New South Wales Government Railways made extensive use of precast concrete construction for its stations and similar buildings. Between 1917 and 1932, they erected 145 such buildings.
Brief history Ancient Roman builders made use of concrete and soon poured the material into moulds to build their complex network of aqueducts, culverts, and tunnels. Modern uses for pre-cast technology include a variety of architectural and structural applications featuring parts of or an entire building system. In the modern world, pre-cast panelled buildings were pioneered in Liverpool, England in 1905. A process was invented by city engineer John Alexander Brodie, whose inventive genius also had him inventing the football goal net. The tram stables at Walton in Liverpool followed in 1906. The idea was not taken up extensively in Britain. However, it was adopted all over the world, particularly in Eastern Europe and Scandinavia. Precast Concrete Products The following is a sampling of the numerous products that utilize precast/prestressed concrete. While this is not a complete list, the majority of precast/prestressed products can fall under one or more of the following categories: Agricultural Products Precast concrete products can withstand the most extreme weather conditions and will hold up for many decades of constant usage. Products include bunker silos, cattle feed bunks, cattle grid, agricultural fencing, H-bunks, J-bunks, livestock slats, livestock watering trough, feed troughs, concrete panels, slurry channels, and more. Prestressed concrete panels are widely used in the UK for a variety of applications including agricultural buildings, grain stores, silage clamps, slurry stores, livestock walling, and general retaining walls. Panels can either be used horizontally and placed either inside the webbings of RSJs (I-beam) or in front of them. Alternatively panels can be cast into a concrete foundation and used as a cantilever retaining wall. Building and Site Amenities Precast concrete building components and site amenities are used architecturally as fireplace mantels, cladding, trim products, accessories, and curtain walls. Structural applications of precast concrete include foundations, beams, floors, walls, and other structural components. It is essential that each structural component be designed and tested to withstand both the tensile and compressive loads that the member will be subjected to over its lifespan.
Precast concrete wall veneer formed to replicate brick. Retaining Walls
An example of a precast concrete retaining wall. Precast concrete provides the manufacturers with the ability to produce a wide range of engineered earth retaining systems. Products include: commercial retaining wall, residential retaining walls, sea walls, mechanically stabilized earth (MSE) panels, modular block systems, segmental retaining walls, etc. Retaining walls have 5 different types which include: gravity retaining wall, semigravity retaining wall, cantilever retaining wall, counterfort retaining wall, and buttress retaining wall. Sanitary and Stormwater Sanitary and Stormwater management products are structures designed for underground installation that have been specifically engineered for the treatment and removal of pollutants from sanitary and stormwater run-off. These precast concrete products include stormwater detention vaults, catch basins, and manholes. Transportation and Traffic Related Products Precast concrete transportation products are used in the construction, safety and site protection of road, airport and railroad transportation systems. Products include: box culverts, 3-sided culverts, bridge systems, railroad crossings, railroad ties, sound walls/barriers, Jersey barriers, tunnel segments, precast concrete barriers, TVCBs, central reservation barriers and other transportation products. These are used to make underpasses, surface-passes and pedestrian subways, so that traffic in cities is disturbed for less amount of time and for other purposes. Precast concrete is also used for the roll ways of some rubber tired metros.
Utility Structures For communications, electrical, gas or steam systems, precast concrete utility structures protect the vital connections and controls for utility distribution. Precast concrete is nontoxic and environmentally safe. Products include: hand holes, hollowcore products, light pole bases, meter boxes, panel vaults, pull boxes, telecommunications structures, transformer pads, transformer vaults, trenches, utility buildings, utility vaults, utility poles, controlled environment vaults (CEVs,) and other utility structures. Water and Wastewater Products Precast water and wastewater products hold or contain water, oil or other liquids for the purpose of further processing into non-contaminating liquids and soil products. Products include: aeration systems, distribution boxes, dosing tanks, dry wells, grease interceptors, leaching pits, sand-oil/oil-water interceptors, septic tanks, water/sewage storage tanks, wetwells, fire cisterns and other water & wastewater products. Specialized Products Cemetery Products Underground vaults or mausoleums - calls for quality watertight structures that withstand the tests of time and the forces of nature.
A precast concrete hazardous material storage container. Hazardous Materials Containment Storage of hazardous material, whether short-term or long-term, is an increasingly important environmental issue, calling for containers that not only seal in the materials, but are strong enough to stand up to natural disasters or terrorist attacks.
A precast concrete armour unit (ACCROPODE). Marine Products Floating docks, underwater infrastructure, decking, railings and a host of amenities are among the uses of precast along the waterfront. When designed with heavy weight in mind, precast products counteract the buoyant forces of water significantly better than most materials. Modular Paving Modular paving is available in a rainbow of colors, shapes, sizes and textures, these versatile precast concrete pieces can be designed to mimic brick, stone or wood. Prestressed/Structural Products Prestressing is a technique of introducing stresses of a predetermined magnitude into a structural member to improve its behavior. This technique is usually found in concrete beams, spandrels, columns, single and double tees, wall panels, segmental bridge units, bulbtee girders, I-beam girders, and others. "Prestressed member are crack-free under working loads and, as a result, look better and more watertight, providing better corrosion protection for the steel." Many projects find that prestressed concrete provides the lowest overall cost, considering production and lifetime maintenance. Reinforced Concrete Box
A reinforced concrete box being used in a storm drain RCC Magic Box, used to build an underpass at Madiwala at the junction of Hosur Road and Inner Ring Road, Bangalore City.
A reinforced concrete box, referred to as a box culvert in the UK and Hong Kong, is a square or rectangular "pipe" made of concrete with rebar or wire mesh fabric strewn throughout for the addition of extra strength. Multiple such boxes are arranged sideways to make a pipe or tunnel like structure. It is often used for sanitary sewer trunks, storm drain spillways, pedestrian subways, utility tunnels, catch basins, and other similar underground passage ways. Due to the enormous strength of reinforced concrete, it is often used in sewers or tunnels that have little cover above them which means they will be subjected to the stress of the road atop them. In India, pre-cast concrete boxes known as "Magic Boxes" are used for the construction of flyovers and underpasses.[12] Double Wall Precast — Concrete Sandwich Panels The double wall process has been in use in Europe for many years. The walls consist of two wythes of concrete separated by an insulated void. The most commonly specified thickness of the wall panels is 8 inches. The walls can also be built to 10 and 12 inches thick if desired. A typical 8-inch wall panel consists of two wythes (layers) of reinforced concrete (each wythe is 2-3/8 inches thick) sandwiched around 3-1/4 inches of high R-value insulating foam. The two wythes of the interior and exterior concrete layers are held together with steel trusses. Concrete sandwich panels held together with steel trusses are inferior to those held together with composite fibreglass connectors. This is because the steel creates a thermal bridge in the wall, significantly reducing the insulative performance and reducing the ability of the building to utilise its thermal mass for energy efficiency. There is also the risk that because steel does not have the same expansion coefficient as that of concrete, as the wall heats and cools, the steel will expand and contract at a different rate to the concrete, which can cause cracking and spalling (concrete "cancer"). Fibreglass connectors that are specially developed to be compatible with concrete significantly reduce this problem. The insulation is continuous
throughout the wall section. The composite sandwich wall section has an R-value exceeding R-22. The wall panels can be made to any height desired, up to a limit of 12 feet. Many owners prefer a 9-foot clear height for the quality of look and feel it affords a building.
A single-family detached home being built up from precast concrete parts The walls can be produced with smooth surfaces on both sides because of the unique manufacturing process, which form finishes both sides. The walls are simply painted or stained on the exterior surface to achieve the desired color or textured surface. When desired, the exterior surface can be manufactured to have a wide variety of brick, stone, wood, or other formed and patterned appearances through the use of reusable, removable formliners. Interior surfaces of the double-wall panels are drywall quality in appearance right out of the plant, requiring only the same prime and paint procedure as is common when completing conventional interior walls made of drywall and studs. Window and door openings are cast into the walls at the manufacturing plant as part of the fabrication process. Electrical and telecommunications conduit and boxes are flush-mounted and cast directly in the panels in the specified locations. The carpenters, electricians, and plumbers do need to make some slight adjustments when first becoming familiar with some of the unique aspects of the wall panels. However, they still perform most of their job duties in the manner to which they are accustomed. Double-wall precast concrete sandwich panels can be used on most every type of building including but not limited to: multi-family, townhouses, condominiums, apartments, hotels and motels, dormitories and schools, and single-family homes. Depending upon building function and layout, the double-wall panels can be easily designed to handle both the structural requirements for strength and safety, as well as the aesthetic and sound attenuation qualities the owner desires. Speed of construction, durability of finished structure, and energy-efficiency are all hallmarks of a building that utilizes the double-wall system. CarbonCast From Wikipedia, the free encyclopedia
(Redirected from Carboncast) Jump to: navigation, search CarbonCast is a precast concrete technology that uses carbon-fibre grid as secondary reinforcing or as a shear truss. It was introduced by AltusGroup, Inc., a North American partnership of 14 precast concrete manufacturers and seven industry suppliers founded to expedite the research and national commercialization of concrete innovations.
Contents
1 Products 2 Properties 3 Applications 4 Examples 5 See also 6 References 7 External links
Products The CarbonCast line of commercial products includes:
CarbonCast High Performance Insulated Wall Panels are composed of two concrete wythes separated by continuous insulation and connected by C-GRID carbon fibre shear trusses CarbonCast Insulated Architectural Cladding feature inner and outer wythes 13⁄4″thick or more for a total concrete thickness of 3-1⁄2″. The wythes sandwich a layer of insulation of usually 2″ or more depending on R-value requirements CarbonCast Architectural Cladding employs a steel reinforced Vierendeel-like truss frame attached to a thin, C-GRID reinforced diaphragm face. Insulating foam forms around patented V-ribs, designed to create a thermal break with the face of the panel, and displaces concrete to provide insulation while C-GRID carbon fibre shear trusses mechanically link the face and truss ribs CarbonCast Double Tees replace conventional steel mesh reinforcing in the flange with C-GRID carbon fibre grid
Properties The use of carbon fibre grid over conventional reinforcement yields a number of unique properties to CarbonCast components:
Lower weight - When carbon fibre grid replaces steel mesh in the face of concrete products, manufacturers can use less concrete cover to protect the mesh from corrosive elements. Non-corrosive carbon fibre eliminates the need for extra concrete. Improved thermal performance - The relatively low thermal conductivity of carbon fibre permits CarbonCast components to provide higher R-values than conventional precast concrete. Improved strength - Carbon fibre is four times stronger than steel by weight providing better surface crack control when used as secondary reinforcing and 100% composite action when used as a truss in insulated wall panels. Comparable cost - Many applications receive savings in foundation and super structure (reduced weight), energy costs (insulation) and maintenance (reduced corrosion).
Applications There are more than 300 projects totaling more than 17,000,000 square feet (1,600,000 m2) of surface area of CarbonCast technology in these markets:
Education Industrial / Warehouse Commercial Office Parking Structure Multi-Family Residential Retail
Examples Prominent structures that have used CarbonCast technology include:
Proximity Hotel, Greensboro, NC Lucas Oil Stadium, Indianapolis, IN University Commons at Georgia State University, Atlanta, GA
RETAIL B U I L D I N G S Design Challenges Precast Concrete Solutions Create tall, open interiors to allow for flexible merchandising space. Architectural precast concrete panels can be designed to provide high ceilings. Design a durable envelope that can withstand impact from forklifts. Precast concrete’s high strength and density provide durability that will withstand impacts. Provide easily accessed delivery docking space. Precast concrete panels’ capability to be cast in 12 ft widths or wider allows docking doors to be built into a single panel, providing inherent stability and fast erection. Provide for future expansion of the facility. Expansion can be accomplished by removing end panels and adding new panels onto the sides. Original mixtures and aggregates can be replicated in added panels to match the existing structure. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during construction. Expedite construction to provide faster return on investment. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single-source responsibility from the precaster. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared. Year-round, allweather construction ensures that schedules are met. Meet the area’s seismic requirements. Precast concrete systems, using proven connection technology, allow precast concrete components to be used in all seismic zones. Fit the structure into surroundings while meeting corporate-identity needs. Architectural precast concrete panels use colors, textures, reveals, finishes, form liners, or thin-brick insets to match any needed design style. These looks can be used for ware house type
stadiums& A R E N A S
Design Challenges Precast Concrete Solutions Design economical rows of seating that can withstand heavy loading. Seating risers, especially economical double and triple risers, are the dominant choice for seating sections in outdoor stadiums and many indoor arenas. Shapes can vary to create needed sight lines, and vibrations can be controlled so that motion during use gives a sense of strength and security. Create an interior structure with smooth traffic flow in and out as well as easy access to all sections. Raker beams, columns, vomitory walls, and other structural components offer cost and time savings with close tolerances, while meeting the configuration requirements of any pedestrian flow requirement. Ensure all materials can withstand year-round weather for many years with minimal maintenance required. Precast concrete mixtures ensure a long life cycle with the capability to withstand use by large capacity crowds. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during construction. Meet the area’s seismic requirements. Precast concrete systems, using proven connection technology, allow precast concrete components to be used in all seismic zones. Create a fast construction pace to ensure that scheduled events occur on time or that new events can be scheduled quickly, providing faster revenue generation. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single source responsibility from the precaster. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared. Year-round, all-weather construction ensures that schedules are met. Create an aesthetic design that fits the owner’s need, whether it is a contemporary look or an old-fashioned stadium design with modern amenities. Architectural precast concrete panels use colors, textures, reveals, finishes, form liners, or thin brick insets to match any needed design style.
Design Challenges Precast Concrete Solutions Meet strict budgeting needs based on tax revenues. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single source responsibility from the precaster, saving costs throughout the construction process. Ensure that the building is ready for the school year in the fall or to meet other deadlines. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared.
Year-round, all-weather construction ensures that schedules are met. Maximize interior floor space. Insulated sandwich wall panels offer an efficient, thin cross-section that maximizes interior floor space while minimizing the footprint. Create needed long-span areas, such as gymnasiums and pools. Hollow-core slabs and double tees can span long spaces to minimize or eliminate columns where needed. Provide for future addition or expansion of classroom spaces. Expansion can be accomplished by removing end panels and adding new panels onto sides. Original mixtures and aggregates can be replicated in added panels. Create a highly fire-resistant structure. Inherently non combustible composition, along with compartmentalization designs, contains fire to specific areas and allows for detection, evacuation, and suppression. Minimize operating costs throughout the life of the building. Minimized joints, compared with brick or block construction, require less maintenance throughout the building’s life. Insulated sandwich wall panels provide high levels of energy efficiency, reducing HVAC costs. Project an image of environmental friendliness by using low-impact products. Precast concrete meets many of the rating criteria used by the LEED standards. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during construction. Meet the area’s seismic requirements. Panelized wall systems and proven connection technology allow precast concrete components to be used in all seismic zones. Provide a strong, institutional look that conveys an educational image. Architectural precast concrete panels use colors, textures, reveals, finishes, formliners, or thinbrick
single- FA M I LY H O M E S DESIGNING WITH PRECAST & PRESTRESSED CONDesign Challenges Precast Concrete Solutions Create an attractive, comfortable appearance that fits with the surrounding neighborhood, whether historic or contemporary. Architectural precast concrete panels use colors, textures, reveals, finishes, form liners, or thin brick insets to match any needed design style. Provide a high-quality, easily maintained façade. Durable concrete and few joints help ensure minimal maintenance of the exterior, even when using thin-brick insets to match nearby brick homes. Ensure fire resistance to reduce insurance costs. Inherently non combustible composition helps contain fire, providing more time for detection, evacuation, and suppression. Concrete roofs and façade help ensure that fires in nearby homes do not spread. Minimize energy use. Insulated sandwich wall panels offer an energy-efficient façade that aids in controlling heating and cooling costs. Maximize lower-level space and eliminate columns for more flexibility. Hollow-core flooring can span long spaces, especially on sloped elevations, to add and open up below-grade spaces. Control acoustics to provide privacy from neighbors. Precast concrete wall panels minimize noise between units. Design a foundation that minimizes chances for moisture penetration. Precast concrete panels used as foundation walls minimize joints and maintenance to control moisture penetration. Construct the home
quickly to expedite occupancy. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single source responsibility from the precaster. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared. Year-round, all-weather construction ensures that schedules are met. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during the construction. Meet the area’s seismic requirements. Precast concrete systems, using proven connection technology, allow precast concrete components to be used in all seismic zones.
A precast concrete walled house in construction 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 lifted into place. In contrast, standard concrete is poured into site-specific forms and cured on site. Precast stone is distinguished from precast concrete by using a fine aggregate in the mixture, so the final product approaches the appearance of naturally occurring rock or stone. By producing precast concrete in a controlled environment (typically referred to as a precast plant), the precast concrete is afforded the opportunity to properly cure and be closely monitored by plant employees. Utilizing a Precast Concrete system offers many potential advantages over site casting of concrete. The production process for Precast Concrete is performed on ground level, which helps with safety throughout a project. There is a greater control of the quality of materials and workmanship in a precast plant rather than on a construction site. Financially, the forms used in a precast plant may be reused hundreds to thousands of times before they have to be replaced, which allows cost of formwork per unit to be lower than for site-cast production. Many states across the United States require a precast plant to be certified by either the Architectural Precast Association (APA), National Precast Concrete Association (NPCA) or Precast Prestressed Concrete Institute (PCI) for a precast producer to supply their product to a construction site sponsored by State and Federal DOTs. There are many different types of precast concrete forming systems for architectural applications, differing in size, function, and cost. Precast architectural panels are also used to clad all or part of a building facade free-standing walls used for landscaping, soundproofing, and security walls, and some can be Prestressed concrete structural elements. Stormwater drainage, water and sewage pipes, and tunnels make use of precast concrete units. The New South Wales Government Railways made extensive use of precast concrete construction for its stations and similar buildings. Between 1917 and 1932, they erected 145 such buildings.
Brief history Ancient Roman builders made use of concrete and soon poured the material into moulds to build their complex network of aqueducts, culverts, and tunnels. Modern uses for pre-cast technology include a variety of architectural and structural applications featuring parts of or an entire building system. In the modern world, pre-cast panelled buildings were pioneered in Liverpool, England in 1905. A process was invented by city engineer John Alexander Brodie, whose inventive genius also had him inventing the football goal net. The tram stables at Walton in Liverpool followed in 1906. The idea was not taken up extensively in Britain. However, it was adopted all over the world, particularly in Eastern Europe and Scandinavia. Precast Concrete Products The following is a sampling of the numerous products that utilize precast/prestressed concrete. While this is not a complete list, the majority of precast/prestressed products can fall under one or more of the following categories: Agricultural Products Precast concrete products can withstand the most extreme weather conditions and will hold up for many decades of constant usage. Products include bunker silos, cattle feed bunks, cattle grid, agricultural fencing, H-bunks, J-bunks, livestock slats, livestock watering trough, feed troughs, concrete panels, slurry channels, and more. Prestressed concrete panels are widely used in the UK for a variety of applications including agricultural buildings, grain stores, silage clamps, slurry stores, livestock walling, and general retaining walls. Panels can either be used horizontally and placed either inside the webbings of RSJs (I-beam) or in front of them. Alternatively panels can be cast into a concrete foundation and used as a cantilever retaining wall. Building and Site Amenities Precast concrete building components and site amenities are used architecturally as fireplace mantels, cladding, trim products, accessories, and curtain walls. Structural applications of precast concrete include foundations, beams, floors, walls, and other structural components. It is essential that each structural component be designed and tested to withstand both the tensile and compressive loads that the member will be subjected to over its lifespan.
Precast concrete wall veneer formed to replicate brick. Retaining Walls
An example of a precast concrete retaining wall. Precast concrete provides the manufacturers with the ability to produce a wide range of engineered earth retaining systems. Products include: commercial retaining wall, residential retaining walls, sea walls, mechanically stabilized earth (MSE) panels, modular block systems, segmental retaining walls, etc. Retaining walls have 5 different types which include: gravity retaining wall, semigravity retaining wall, cantilever retaining wall, counterfort retaining wall, and buttress retaining wall. Sanitary and Stormwater Sanitary and Stormwater management products are structures designed for underground installation that have been specifically engineered for the treatment and removal of pollutants from sanitary and stormwater run-off. These precast concrete products include stormwater detention vaults, catch basins, and manholes. Transportation and Traffic Related Products Precast concrete transportation products are used in the construction, safety and site protection of road, airport and railroad transportation systems. Products include: box culverts, 3-sided culverts, bridge systems, railroad crossings, railroad ties, sound walls/barriers, Jersey barriers, tunnel segments, precast concrete barriers, TVCBs, central reservation barriers and other transportation products. These are used to make underpasses, surface-passes and pedestrian subways, so that traffic in cities is disturbed for less amount of time and for other purposes. Precast concrete is also used for the roll ways of some rubber tired metros.
Utility Structures For communications, electrical, gas or steam systems, precast concrete utility structures protect the vital connections and controls for utility distribution. Precast concrete is nontoxic and environmentally safe. Products include: hand holes, hollowcore products, light pole bases, meter boxes, panel vaults, pull boxes, telecommunications structures, transformer pads, transformer vaults, trenches, utility buildings, utility vaults, utility poles, controlled environment vaults (CEVs,) and other utility structures. Water and Wastewater Products Precast water and wastewater products hold or contain water, oil or other liquids for the purpose of further processing into non-contaminating liquids and soil products. Products include: aeration systems, distribution boxes, dosing tanks, dry wells, grease interceptors, leaching pits, sand-oil/oil-water interceptors, septic tanks, water/sewage storage tanks, wetwells, fire cisterns and other water & wastewater products. Specialized Products Cemetery Products Underground vaults or mausoleums - calls for quality watertight structures that withstand the tests of time and the forces of nature.
A precast concrete hazardous material storage container. Hazardous Materials Containment Storage of hazardous material, whether short-term or long-term, is an increasingly important environmental issue, calling for containers that not only seal in the materials, but are strong enough to stand up to natural disasters or terrorist attacks.
A precast concrete armour unit (ACCROPODE). Marine Products Floating docks, underwater infrastructure, decking, railings and a host of amenities are among the uses of precast along the waterfront. When designed with heavy weight in mind, precast products counteract the buoyant forces of water significantly better than most materials. Modular Paving Modular paving is available in a rainbow of colors, shapes, sizes and textures, these versatile precast concrete pieces can be designed to mimic brick, stone or wood. Prestressed/Structural Products Prestressing is a technique of introducing stresses of a predetermined magnitude into a structural member to improve its behavior. This technique is usually found in concrete beams, spandrels, columns, single and double tees, wall panels, segmental bridge units, bulbtee girders, I-beam girders, and others. "Prestressed member are crack-free under working loads and, as a result, look better and more watertight, providing better corrosion protection for the steel." Many projects find that prestressed concrete provides the lowest overall cost, considering production and lifetime maintenance. Reinforced Concrete Box
A reinforced concrete box being used in a storm drain RCC Magic Box, used to build an underpass at Madiwala at the junction of Hosur Road and Inner Ring Road, Bangalore City.
A reinforced concrete box, referred to as a box culvert in the UK and Hong Kong, is a square or rectangular "pipe" made of concrete with rebar or wire mesh fabric strewn throughout for the addition of extra strength. Multiple such boxes are arranged sideways to make a pipe or tunnel like structure. It is often used for sanitary sewer trunks, storm drain spillways, pedestrian subways, utility tunnels, catch basins, and other similar underground passage ways. Due to the enormous strength of reinforced concrete, it is often used in sewers or tunnels that have little cover above them which means they will be subjected to the stress of the road atop them. In India, pre-cast concrete boxes known as "Magic Boxes" are used for the construction of flyovers and underpasses.[12] Double Wall Precast — Concrete Sandwich Panels The double wall process has been in use in Europe for many years. The walls consist of two wythes of concrete separated by an insulated void. The most commonly specified thickness of the wall panels is 8 inches. The walls can also be built to 10 and 12 inches thick if desired. A typical 8-inch wall panel consists of two wythes (layers) of reinforced concrete (each wythe is 2-3/8 inches thick) sandwiched around 3-1/4 inches of high R-value insulating foam. The two wythes of the interior and exterior concrete layers are held together with steel trusses. Concrete sandwich panels held together with steel trusses are inferior to those held together with composite fibreglass connectors. This is because the steel creates a thermal bridge in the wall, significantly reducing the insulative performance and reducing the ability of the building to utilise its thermal mass for energy efficiency. There is also the risk that because steel does not have the same expansion coefficient as that of concrete, as the wall heats and cools, the steel will expand and contract at a different rate to the concrete, which can cause cracking and spalling (concrete "cancer"). Fibreglass connectors that are specially developed to be compatible with concrete significantly reduce this problem. The insulation is continuous
throughout the wall section. The composite sandwich wall section has an R-value exceeding R-22. The wall panels can be made to any height desired, up to a limit of 12 feet. Many owners prefer a 9-foot clear height for the quality of look and feel it affords a building.
A single-family detached home being built up from precast concrete parts The walls can be produced with smooth surfaces on both sides because of the unique manufacturing process, which form finishes both sides. The walls are simply painted or stained on the exterior surface to achieve the desired color or textured surface. When desired, the exterior surface can be manufactured to have a wide variety of brick, stone, wood, or other formed and patterned appearances through the use of reusable, removable formliners. Interior surfaces of the double-wall panels are drywall quality in appearance right out of the plant, requiring only the same prime and paint procedure as is common when completing conventional interior walls made of drywall and studs. Window and door openings are cast into the walls at the manufacturing plant as part of the fabrication process. Electrical and telecommunications conduit and boxes are flush-mounted and cast directly in the panels in the specified locations. The carpenters, electricians, and plumbers do need to make some slight adjustments when first becoming familiar with some of the unique aspects of the wall panels. However, they still perform most of their job duties in the manner to which they are accustomed. Double-wall precast concrete sandwich panels can be used on most every type of building including but not limited to: multi-family, townhouses, condominiums, apartments, hotels and motels, dormitories and schools, and single-family homes. Depending upon building function and layout, the double-wall panels can be easily designed to handle both the structural requirements for strength and safety, as well as the aesthetic and sound attenuation qualities the owner desires. Speed of construction, durability of finished structure, and energy-efficiency are all hallmarks of a building that utilizes the double-wall system. CarbonCast From Wikipedia, the free encyclopedia
(Redirected from Carboncast) Jump to: navigation, search CarbonCast is a precast concrete technology that uses carbon-fibre grid as secondary reinforcing or as a shear truss. It was introduced by AltusGroup, Inc., a North American partnership of 14 precast concrete manufacturers and seven industry suppliers founded to expedite the research and national commercialization of concrete innovations.
Contents
1 Products 2 Properties 3 Applications 4 Examples 5 See also 6 References 7 External links
Products The CarbonCast line of commercial products includes:
CarbonCast High Performance Insulated Wall Panels are composed of two concrete wythes separated by continuous insulation and connected by C-GRID carbon fibre shear trusses CarbonCast Insulated Architectural Cladding feature inner and outer wythes 13⁄4″thick or more for a total concrete thickness of 3-1⁄2″. The wythes sandwich a layer of insulation of usually 2″ or more depending on R-value requirements CarbonCast Architectural Cladding employs a steel reinforced Vierendeel-like truss frame attached to a thin, C-GRID reinforced diaphragm face. Insulating foam forms around patented V-ribs, designed to create a thermal break with the face of the panel, and displaces concrete to provide insulation while C-GRID carbon fibre shear trusses mechanically link the face and truss ribs CarbonCast Double Tees replace conventional steel mesh reinforcing in the flange with C-GRID carbon fibre grid
Properties The use of carbon fibre grid over conventional reinforcement yields a number of unique properties to CarbonCast components:
Lower weight - When carbon fibre grid replaces steel mesh in the face of concrete products, manufacturers can use less concrete cover to protect the mesh from corrosive elements. Non-corrosive carbon fibre eliminates the need for extra concrete. Improved thermal performance - The relatively low thermal conductivity of carbon fibre permits CarbonCast components to provide higher R-values than conventional precast concrete. Improved strength - Carbon fibre is four times stronger than steel by weight providing better surface crack control when used as secondary reinforcing and 100% composite action when used as a truss in insulated wall panels. Comparable cost - Many applications receive savings in foundation and super structure (reduced weight), energy costs (insulation) and maintenance (reduced corrosion).
Applications There are more than 300 projects totaling more than 17,000,000 square feet (1,600,000 m2) of surface area of CarbonCast technology in these markets:
Education Industrial / Warehouse Commercial Office Parking Structure Multi-Family Residential Retail
Examples Prominent structures that have used CarbonCast technology include:
Proximity Hotel, Greensboro, NC Lucas Oil Stadium, Indianapolis, IN University Commons at Georgia State University, Atlanta, GA
RETAIL B U I L D I N G S Design Challenges Precast Concrete Solutions Create tall, open interiors to allow for flexible merchandising space. Architectural precast concrete panels can be designed to provide high ceilings. Design a durable envelope that can withstand impact from forklifts. Precast concrete’s high strength and density provide durability that will withstand impacts. Provide easily accessed delivery docking space. Precast concrete panels’ capability to be cast in 12 ft widths or wider allows docking doors to be built into a single panel, providing inherent stability and fast erection. Provide for future expansion of the facility. Expansion can be accomplished by removing end panels and adding new panels onto the sides. Original mixtures and aggregates can be replicated in added panels to match the existing structure. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during construction. Expedite construction to provide faster return on investment. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single-source responsibility from the precaster. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared. Year-round, allweather construction ensures that schedules are met. Meet the area’s seismic requirements. Precast concrete systems, using proven connection technology, allow precast concrete components to be used in all seismic zones. Fit the structure into surroundings while meeting corporate-identity needs. Architectural precast concrete panels use colors, textures, reveals, finishes, form liners, or thin-brick insets to match any needed design style. These looks can be used for ware house type
stadiums& A R E N A S
Design Challenges Precast Concrete Solutions Design economical rows of seating that can withstand heavy loading. Seating risers, especially economical double and triple risers, are the dominant choice for seating sections in outdoor stadiums and many indoor arenas. Shapes can vary to create needed sight lines, and vibrations can be controlled so that motion during use gives a sense of strength and security. Create an interior structure with smooth traffic flow in and out as well as easy access to all sections. Raker beams, columns, vomitory walls, and other structural components offer cost and time savings with close tolerances, while meeting the configuration requirements of any pedestrian flow requirement. Ensure all materials can withstand year-round weather for many years with minimal maintenance required. Precast concrete mixtures ensure a long life cycle with the capability to withstand use by large capacity crowds. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during construction. Meet the area’s seismic requirements. Precast concrete systems, using proven connection technology, allow precast concrete components to be used in all seismic zones. Create a fast construction pace to ensure that scheduled events occur on time or that new events can be scheduled quickly, providing faster revenue generation. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single source responsibility from the precaster. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared. Year-round, all-weather construction ensures that schedules are met. Create an aesthetic design that fits the owner’s need, whether it is a contemporary look or an old-fashioned stadium design with modern amenities. Architectural precast concrete panels use colors, textures, reveals, finishes, form liners, or thin brick insets to match any needed design style.
Design Challenges Precast Concrete Solutions Meet strict budgeting needs based on tax revenues. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single source responsibility from the precaster, saving costs throughout the construction process. Ensure that the building is ready for the school year in the fall or to meet other deadlines. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared.
Year-round, all-weather construction ensures that schedules are met. Maximize interior floor space. Insulated sandwich wall panels offer an efficient, thin cross-section that maximizes interior floor space while minimizing the footprint. Create needed long-span areas, such as gymnasiums and pools. Hollow-core slabs and double tees can span long spaces to minimize or eliminate columns where needed. Provide for future addition or expansion of classroom spaces. Expansion can be accomplished by removing end panels and adding new panels onto sides. Original mixtures and aggregates can be replicated in added panels. Create a highly fire-resistant structure. Inherently non combustible composition, along with compartmentalization designs, contains fire to specific areas and allows for detection, evacuation, and suppression. Minimize operating costs throughout the life of the building. Minimized joints, compared with brick or block construction, require less maintenance throughout the building’s life. Insulated sandwich wall panels provide high levels of energy efficiency, reducing HVAC costs. Project an image of environmental friendliness by using low-impact products. Precast concrete meets many of the rating criteria used by the LEED standards. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during construction. Meet the area’s seismic requirements. Panelized wall systems and proven connection technology allow precast concrete components to be used in all seismic zones. Provide a strong, institutional look that conveys an educational image. Architectural precast concrete panels use colors, textures, reveals, finishes, formliners, or thinbrick
single- FA M I LY H O M E S DESIGNING WITH PRECAST & PRESTRESSED CONDesign Challenges Precast Concrete Solutions Create an attractive, comfortable appearance that fits with the surrounding neighborhood, whether historic or contemporary. Architectural precast concrete panels use colors, textures, reveals, finishes, form liners, or thin brick insets to match any needed design style. Provide a high-quality, easily maintained façade. Durable concrete and few joints help ensure minimal maintenance of the exterior, even when using thin-brick insets to match nearby brick homes. Ensure fire resistance to reduce insurance costs. Inherently non combustible composition helps contain fire, providing more time for detection, evacuation, and suppression. Concrete roofs and façade help ensure that fires in nearby homes do not spread. Minimize energy use. Insulated sandwich wall panels offer an energy-efficient façade that aids in controlling heating and cooling costs. Maximize lower-level space and eliminate columns for more flexibility. Hollow-core flooring can span long spaces, especially on sloped elevations, to add and open up below-grade spaces. Control acoustics to provide privacy from neighbors. Precast concrete wall panels minimize noise between units. Design a foundation that minimizes chances for moisture penetration. Precast concrete panels used as foundation walls minimize joints and maintenance to control moisture penetration. Construct the home
quickly to expedite occupancy. A total precast concrete system expedites construction, minimizes the number of component pieces by combining structural and architectural attributes into a single piece, and offers single source responsibility from the precaster. Component casting begins when the shop drawings are complete, ensuring that erection begins as soon as the site is prepared. Year-round, all-weather construction ensures that schedules are met. Minimize congestion and safety concerns on site and in the general vicinity during construction. Precast concrete components can be brought to the site as needed for that day’s erection, and staging areas can be arranged nearby. Fabrication of components off site ensures less traffic on the site and less congestion in the vicinity during the construction. Meet the area’s seismic requirements. Precast concrete systems, using proven connection technology, allow precast concrete components to be used in all seismic zones.
