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Applications
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Cast in Place
Ready-mix concrete poured in forms on-site
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| Truck agitator for ready mixed concrete (PCA No.69926) | Cast-in-place concrete is transported in an unhardened state, primarily as ready-mix, and placed in forms. Ready mixed concrete is proportioned and mixed off the project site. The concrete is delivered to the site in a truck agitator (often incorrectly called a “cement truck”) but can also be delivered in a non-agitating truck. Specialized paving equipment may be used to mix and spread concrete for pavement. |
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- Most foundations and slabs-on-ground
- Walls, beams, columns, floors, roofs
- Large portions of bridges, pavements, and other infrastructure.
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| Concrete was selected for ceilings, floors and framing inside this station. (PCA No. 10074) | Cast-in-place concrete is the material of choice for slab-on-ground and foundations because of its long-term durability and structural support. It is also used in all types of buildings for either structural support as beams and columns, as well as for floors, walls, and roofs. |
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Ready mixed concrete has many environmental benefits during construction and for the life of the structure. See associated sustainability solutions and technical briefs (right) for more detail.
During construction:
Waste Minimization. Concrete is ordered and placed as needed and does not need to be trimmed or cut after installation. Wash water is frequently recycled using trucks equipped with devices that collect wash water and return it to the drum where it can be returned to the ready mixed concrete plant for recycling.
Extra concrete is often returned to the ready-mix plant where it is recycled or used to make jersey barriers or retaining wall blocks; or it can be washed to recycle the coarse aggregate. Special set retarding admixtures can be added to returned concrete to allow for storage and future use.
Local. Materials are usually extracted and manufactured locally. May contribute to LEED Credit M 5.
Recycled content. Fly ash, slag cement, or silica fume can substitute partially for cement, and recycled aggregates can replace newly mined gravel. Recycled content can contribute to LEED Credit M 4.
During the life of the structure:
Energy Performance and Thermal Mass. Thermal mass improves energy performance when appropriately insulated. When 3 in. or more in thickness, concrete forms an air barrier. May contribute to LEED Credit EA 1.
Durable. Concrete stands up to natural disasters, wind-driven rain, moisture damage, and vermin. Less replacement means reduced resource requirements.
Cool. Using light- or natural-colored material helps reduce the heat island affect. When used for exposed horizontal surfaces may contribute to LEED Credit SS 7.
Low emitting. Concrete has low VOC emission and does not degrade indoor air quality.
Recyclable. Concrete is commonly recycled in urban areas into fill and road base material at the end of service life. When existing concrete is recycled during construction, may contribute to LEED Credit M 2. |
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| Concrete was the primary building material used to construct the Pierce Transit North End Turna Around Facility in Tacoma, Washington. A pedestrian ramp snakes between more than 60 cast-in-place waterfall and landscaping containers at the Turnaround. The ramp connects the assembly plaza with the downtown transit bus transfer area below. The compex geometry of the project, combined with the watertightness and durability considerations, made concrete the logical choice. (PCA No. 10088). |
Mix. The design professional specifies the appropriate concrete properties for a particular project and use, and an appropriate mix design is developed. The mix design specifies the amount and type of cementitious materials, water, and aggregate (sand, gravel, or crushed rock). Mixing, transporting, and handling of concrete are coordinated with placing and finishing operations.
Placement. Concrete should not be placed more rapidly than it can be spread, struck off, and consolidated. It should be deposited continuously as near as possible to its final position. In many types of construction, concrete is placed in forms and consolidated. Consolidation compacts fresh concrete to mold it within the forms around embedded items and reinforcement and eliminates stone pockets, honeycombing, and entrapped air. Vibration is the most widely used method for consolidating concrete. Self-compacting concrete, also referred to self-consolidating concrete, is able to flow and consolidate under its own weight and requires no vibration.
Curing. After the concrete is placed, a satisfactory moisture content and temperature is required for concrete to develop adequate strength and durability; this is called the curing process. Curing compounds or other surface treatments prevent the rapid loss of moisture from the surface of concrete and aid in the curing process.
Finishing. Exposed concrete surfaces, usually the top surface, generally require finishing if they will be visible. This includes driveways, pavements, sidewalks, floors, slabs, and other flatwork. Options include various colors and textures, such as exposed aggregate or a pattern-stamped surface. Some surfaces may require only strikeoff or screeding (which removes excess concrete and evens out the exposed surface) to the proper contour and elevation. Other surfaces may have a broomed, floated, or trowel finish. Sawcut joints, if required, are made after the concrete is sufficiently hard or strong to prevent raveling (is the disintegration of the surface to leave loose or protruding aggregates).
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- BOOKMARK
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 LEED Reference Guide (2006) RMC Research Foundation, National Ready Mixed Concrete Association,
This 89 page invaluable reference manual for architects, specifiers, contractors and building owners will guide the user through the steps to achieve LEED NC v 2.2 credits using ready mix concrete materials. Strategies, examples and detailed instructions help users understand how concrete can contribute to urban heat island reduction, energy savings, storm water quality and quantity, recycled content and local availability credit. Available as a free .pdf
 2005 ASHRAE Handbook - Fundamentals (2005) ASHRAE
The 2005 volume of the ASHRAE Handbook covers basic principles and provides essential data for HVAC&R design. In all, the Fundamentals volume includes more than 1,000 pages and 40 chapters on a variety of HVAC&R topics, covering general engineering information, basic materials, load and energy calculations and duct and pipe design. Available for $155
Cast In Place Walls (2000) Portland Cement Association. Item Code: LT117
Available for $28.50.
A training aid for apprentices, journeymen, and foreman in the area of cast in place walls. Not a design manual, but a guide to good practice.
Comparison of Environmental Effects of Steel- and Concrete-Framed Buildings (2005) Angela Acree Guggemos and Arpad Horvath, Journal of Infrastructure Systems, Vol 11, page 93
Available for $25, free through subscribing institution.
In order to create an environmentally-conscious building, the environmental impacts of the entire service life must be known. Life-cycle assessment (LCA), which evaluates the impacts from all life-cycle phases, from "cradle to grave," is the best method to achieve this goal. In this paper, LCA is used to quantify the energy use and the environmental emissions during the construction phase of two typical office buildings, one with a structural steel frame and one with a cast-in-place concrete frame, and then these are put in the perspective of the overall service life of each building. The concrete structural-frame construction has more associated energy use, CO2, CO, NO2, particulate matter, SO2, and hydrocarbon emissions due to more formwork used, larger transportation impacts due to a larger mass of materials, and longer equipment use due to the longer installation process. In contrast, the steel-frame construction has more volatile organic compound (VOC) and heavy metal (Cr, Ni, Mn) emissions due to the painting, torch cutting, and welding of the steel members. The energy use and the environmental emissions of the two buildings are comparable if the total impacts from materials' manufacturing, construction, transportation, use, maintenance, and demolition are considered. Energy use and environmental emissions from office buildings can be reduced through a careful selection of embedded and temporary materials and construction equipment.
Concrete Floors and Moisture (2005) Portland Cement Association. Item Code: EB119
Available for $40.
A resource on how to handle moisture with concrete floor systems. It discussed sources of moisture, drying concrete, methods of measuring moisture, construction practices, specifications, and responsibilities for successful floor projects.
Concrete in PracticeNational Ready Mixed Concrete Association
Available for $25. Free to download nonprinting PDF
A series of 38 one page information sheets on important technical topics, written in a non-technical format.
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