Cast in Place
Ready-mix concrete poured in forms on-site
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.
|Truck agitator for ready mixed concrete (PCA No.69926)|
- Most foundations and slabs-on-ground
- Walls, beams, columns, floors, roofs
- Large portions of bridges, pavements, and other infrastructure.
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.
|Concrete was selected for ceilings, floors and framing inside this station. (PCA No. 10074)|
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.
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.
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.
|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).
|LEED Reference Guide
RMC Research Foundation, National Ready Mixed Concrete Association,
This invaluable reference manual for architects, specifiers, contractors and building owners will guide the user through the steps to achieve LEED NC v 3.0 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
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
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
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
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 Practice
National 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.
Concrete: Sustainability and Life Cycle
Portland Cement Association. Item Code: SN3011
Available for download for free
This report presents the results of the LCI of three concrete products: ready mixed concrete, concrete masonry, and precast concrete.
Design and Control of Concrete Mixtures, 14th Edition
S.H. Kosmatka, B. Kerkhoff, and W.C. Panarese, Portland Cement Association, Item Code EB001, 372 pages
Available for $80
Definitive reference on concrete technology covers fundamentals and detailed information on freshly mixed and hardened concrete. Extensively updated and expanded, this new edition discusses materials for concrete, such as portland cements, supplementary cementing materials, aggregates, admixtures and fibers; air entrainment; procedures for mix proportioning, batching, mixing, transporting, handling, placing, consolidating, finishing, and curing concrete; precautions necessary during hot- and cold-weather concreting; causes and methods of controlling volume changes; commonly used control tests for quality concrete; special types of concrete, such as high-performance, lightweight, heavyweight, no-slump, roller-compacted, shotcrete, mass concrete and many more. Applicable ASTM, AASHTO, and ACI standards are referred to extensively.
HVAC Sizing for Concrete Homes
Portland Cement Association. Item Code: CD044
Available for $60.
This software provides an alternative means of estimating heating and cooling system capacities for single-family concrete homes. The software calculates the system capacities based on the house dimensions, construction materials, location (U.S. and Canada) and thermostat set point.
Influence of Pavement Reflectance on Lighting for Parking Lots
Adrian, W. and Jobanputra, R. Item Code: SN2458
Available for free.
This investigation has compared the lighting performance of concrete and asphalt surfaces of parking lots. The resulting amount of energy saved for a typical parking lot lighting system was attained for equivalent average surface luminances. Equivalent average surfaces were compared in two ways: by modifying lamp power and by reducing the number of lighting poles.
Sound Transmission Loss Through Concrete and Concrete Masonry Wall
Albert Litvin and Harold W. Belliston, Portland Cement Association, Item Code RD066
Many building codes require minimum sound transmission loss values, expressed as sound transmission class (STC), of 45 to 50. Tests of sound transmission loss were made on 8-in.-thick (203-mm) concrete masonry walls and on 6- and 8-in.-thick (152- and 203-mm) cast concrete walls finished with materials intended to increase sound transmission loss. Using furring, acoustic insulation, and wallboard attachments, STC values up to 59 and 63 were obtained for the masonry and cast concrete walls, respectively. Selected STC values, reported by other investigators, for a variety of walls are included for reference.
Standard 90.1-2001 - Energy Standard for Buildings Except Low-Rise Residential Buildings
ASHRAE. ISBN/ISSN: 1041-2336
Available for $88 member, $110 non-member.
Incorporates 34 new addenda covering a wide range of topics, as well as editorial changes and updates to the body of the standard. The new addenda contain information on minimum energy efficiency standards, building envelope requirements, zone isolation, floor, ceiling and roof insulation, and power allowance calculation.
Supplementary Cementing Materials for Use in Blended Cements
Portland Cement Association. Item Code: RD112
Available for $40.
Provides information on using fly ash, slag, silica fume and natural pozzolans in the manufacturing of blended cements and the effects of these materials on cement and concrete. This report is also found on CD019 and DVD019.
Supplementary Cementing Materials For Use in Concrete
Michael Thomas and Michelle L. Wilson. Portland Cement Association. Item Code: CD038
Available for $35.
The first of a series of interactive distance learning programs specifically designed for training individuals on cement and concrete technology. This fully-narrated CD provides an intense self-contained course on supplementary cementing materials (SCMs) and their impact on the durability, workability, economy, and sustainability of concrete.
Thermal Mass Comparison of Wall Systems
Portland Cement Association. Item Code: CD026
Available for $35.
This 49-page report provides the thermal performance of eleven different structural wall systems: concrete masonry, insulated cast-in-place, insulated concrete forms, and AAC as well as wood and steel frame. The results illustrate the benefits of thermal mass, depending on climatic conditions for most of North America.
An Engineers Guide to: Economical Concrete Floor Systems
This 6-page bulletin presents information on cast-in-place reinforced concrete floor systems. The publication includes guidelines for selecting different floor systems for virtually any span and loading condition. The emphasis is on selecting cost-effective slab system for different situations. Also included are design aids for preliminary thickness estimation. The floor systems covered are; flat plate, flat slab, one-way joist, wide-module joist, two-way joist, and banded-beam. In addition information on drop panel, form work details, standard form dimensions for one-way and two-way joist construction is also included.
Life Cycle Cost Literature Survey
Katie Amelio and Martha G. VanGeem, PCA R&D Serial No. 2484, Portland Cement Association, 41 pgs
Available for free.
Life cycle cost analysis is currently a valuable tool in the construction industry and will become more so as resources become more scarce. Selecting the materials and components of structures and pavements based on a life cycle cost analysis can significantly decrease
the lifetime cost of construction, maintenance and repair.
This literature survey gathers life cycle cost information for concrete and competing materials from a variety of sources, summarizes the results, and describes the resulting
searchable database. The database is a resourceful tool for those who would like to obtain additional information on life cycle cost analysis and results. The searchable life cycle cost
database with abstracts, in Filemaker Pro® format, is available to Portland Cement
Association (PCA) member companies, PCA staff, and cement promotion groups.
Light Reflective Floors
Portland Cement Association, #IS529, 2 pages
Available for free.
Light reflective floors increase illumination inside buildings. Using white cement concrete to build new floors or top existing ones provides a low-maintenance floor that saves energy and improves the indoor environment.
Slag Cement LEED NC 2.1 Guide
Slag Cement Association
Available for free.
This 17-page publication discusses how slag cement can help contribute to achieving 9 different points toward for LEED™-NC certification.
Sustainable Manufacturing Fact Sheet: Tire Derived Fuel
Portland Cement Association. Item Code: IS325
Available for free.
By utilizing a cement kiln's controlled combustion environment, scrap tires can be an environmentally-sound source of energy in the manufacture of cement. This fact sheet shows how the popularity of tire-derived fuel has increased over the past two decades and summarizes its environmental benefits.
The Art of Concrete
Portland Cement Association. Item Code: PL721
Available for free.
White and colored concrete made with white cement have numerous applications, from cast-in-place to precast to tilt-up. This attractive brochure highlights the benefits of this versatile material, which can be used for decorative and structural purposes.
What's Your IAQ I.Q.?
Environmental Council of Concrete Organizations, #2846
Architects, engineers, and builders are becoming more proactive in assuring the Indoor Air Quality (IAQ) of the buildings for which they are responsible. Concrete is the best building material for forestalling sick building syndrome. Concrete also reduces the outgassing of indoor air pollutants. Because concrete structures are more energy efficient, they lower emissions form furnaces. This document is available for free from Environmental Council of Concrete Organizations.
To find this article: Follow the link provided, then click "catalog" and scroll half way down the page to find the article.
Building Even Better Concrete
Originally printed in the December 2007 of Architectural Record, this article by Joann Gonchar, AIA of McGraw-Hill looks at the current trends in cement and concrete construction that improve performance and reduce environmental impact. One hour of AIA Continuing Education Credit is available on-line through McGraw-Hill by reading the article and completing a brief test.
Changes In Store
Wal-Mart showcases green concrete technologies at its store in Texas.
This 4 page article was originally featured in the May 2006 edition of Concrete Producer Magazine, by Hanley Wood. Wal-Mart testing a range of green strategies at this prototype store in McKinney, TX. Along with other green strategies, concrete was used as interior finish flooring, reducing VOC's and maintenance, and pervious pavement in the parking area to improve ground water quality and quantity.
Green Value - Green Buildings Good For Business
Royal Institution of Chartered Surveyors.
Green Value is an independent research study that looked at green buildings in Canada, the USA and the UK. It concludes that a clear link is beginning to emerge between the market value of a building and its green features.
The Construction Specifier, by Howard Jancy, CSI, CDT, and Greg Schwietz, SCI, CDT, 2007
Polishing concrete can be used to refurbish old or damaged floors or add dimension to new ones. The process to attain glossy surfaces is discussed, along with safety standards, maintenance, and chemical treatments to protect floors. This discussion also includes an overview of materials used to color concrete surfaces to add a further decorative element.