« Return to BuildingGreen.com
  • Remove facet 03 00 00: Concrete
View: GridList

Concrete is widely used in all types of construction because of its compressive strength, durability, and the way it can be formed into a myriad of shapes. Concrete also provides thermal mass and, if finished right, can be both structure and an interior or exterior finished surface, avoiding the need to apply additional layers of finish.

Portland cement, which gives most concrete the ability to cure into a stone-like material, is energy-intensive and polluting to produce—up to a ton of carbon dioxide is released in producing a ton of cement. Strategies for reducing the environmental impact of concrete typically involve using less concrete or making the concrete with less cement.

Making concrete with less cement

Coal fly ash is a waste product of coal-fired power plants and can be used as a substitute for some of the portland cement in a concrete mixture. Up to 60% is common, but even higher levels of substitution are possible. It slows curing but ultimately makes the concrete stronger and gives it improved workability compared with a conventional mix. Trace heavy metals are found in fly ash, but they are also found in cement, and, once locked up concrete, are unlikely to represent a health hazard.

Other industrial and agricultural waste products, including ground blast-furnace slag and rice-hull ash, can also be used to replace some of the portland cement in concrete. For some applications, magnesium oxide cement and other alternatives to portland cement are being explored.

On large jobs, it’s possible to have the concrete mix designed specifically to reduce cement without compromising other properties. Some engineers and ready-mix plants offer proprietary technologies for optimizing a mix with minimal use of specialized admixtures.

Using less concrete

Smart design choices and specialized forming products can reduce the amount of concrete needed without compromising structural integrity. Precast concrete members use less concrete than site-formed elements with optimized geometries and aeration, which reduces the mass of concrete while improving its insulation value. Precast elements can also speed construction and reduce environmental damage on the construction site.

Stay-in-place insulating concrete forms (ICFs) made of polystyrene foam or a cementitious matrix of recycled foam or recycled wood fibers can reduce the amount of concrete used, avoid the impacts of temporary forms, and provide high levels of insulation.

Other green opportunities with concrete

A wide range of additives and admixtures are used to adjust the properties of concrete including accelerators, bonding agents, curing agents, densifiers, hardeners, plasticizers, retarders, sealers, and coloring agents. These can help make better concrete, but often come with their own environmental downsides, so seek out low-impact alternatives.

Forming can account for a significant portion of the total cost of poured concrete. Essentially, things get built twice: once in forms and again in concrete. Plywood has been the mainstay of concrete-forming companies for many years, though some companies have invested in reusable, durable forms—a more resource-efficient solution that is still relatively labor-intensive.

Forms also require form-release agents, most of which are petrochemical-based and off-gas large amounts of volatile organic compounds (VOCs). Vegetable-based form-release oils are available.

Recycled, lightweight, or thermally resistive aggregates offer reduced upstream impacts and/or improved properties in the finished concrete.

Walls and decks made of concrete do not provide much thermal insulation, but they can provide thermal mass which can help stabilize temperatures. To reduce thermal bridging, design walls, roofs, and foundations so that concrete does not extend all the way from interior to exterior.

Flowable cementitious mixes can also help with renovation of older buildings, by helping to level floors and correct roof slopes.

Concrete is widely used in all types of construction because of its compressive strength, durability, and the way it can be formed into a myriad of shapes. Concrete also provides thermal mass and, if finished right, can be both structure and an interior or exterior finished surface, avoiding the need to apply additional layers of finish.

Portland cement, which gives most concrete the ability to cure into a stone-like material, is energy-intensive and polluting to produce—up to a ton of carbon dioxide is released in producing a ton of cement. Strategies for reducing the environmental impact of concrete typically involve using less concrete or making the concrete with less cement.

  • Cellucrete Lightweight Insulating Concrete
  • Cellucrete Lightweight Insulating Concrete
  • Cellucrete
  • Cellucrete Lightweight Insulating Concrete
    Cellucrete
    Cellucrete is certified to apply the Elastizell Roof Deck System, which consists of a low density foamed cement slurry cast over embedded EPS insulation up to 12" thick (R-4/inch). The slurry is air-entrained on site with proprietary protein-stabilized surfactants using specialized foaming and mixing equipment. The use of other additives may be specified. Cast densities from 30–50 pcf for various applications have R-values ranging from 0.86–1.8 per inch. Elastizell insulating concrete is applied over fluted metal, concrete, or wood decks; it fills depressions and flutes to eliminate potential air and water channels. The product is positively sloped during installation to achieve proper drainage and eliminate ponding. Then, a built-up or single-ply roofing membrane is applied directly to the sloped surface. The EPS insulation sandwiched within the insulating concrete is protected during future roofing replacement.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Geo-Blue Crete
  • Geo-Blue Crete
  • Blue World Crete Inc.
  • Geo-Blue Crete
    Blue World Crete Inc.
    Geo-Blue Crete is a proprietary hybrid of geopolymers and “nano-ceramic” cement that is mixed and used similarly to ordinary portland cement (OPC). Geo-Blue does not require calcining limestone, so the manufacturing energy and CO2 production are significantly less than portland cement, and one of the primary ingredients is derived from algae. According to the company, concrete made with Geo-Blue resists water and acids and reaches three times the compressive and tensile strength of portland cement-based concrete, and also has improved heat resistance and thermal properties. It can be formulated for use with slag, fly ash, kaolin clays, and other pozzolins. This technology is more affordable than other geopolymer cements and competitive with portland cement, according to the company. It can be licensed to companies that will produce concrete; however there are currently no licensees in the U.S.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Laticrete Grouts
  • Laticrete Grouts
  • Laticrete International, Inc.
  • Laticrete Grouts
    Laticrete International, Inc.
    Laticrete makes a number of grouts that are Greenguard Gold-certified for low emissions, including the 1500 Sanded Grout and 1600 Unsanded Grout. These are cementitious products made from portland cement and proprietary polymers. The 1500 is a hard, durable product for joint widths from 1/16" to 3/8" that can be used outdoors and 1600 is for narrow joints up to 1/8", such as found in wall tile or stone. These products do not contain antimicrobial compounds, which GreenSpec recommends avoiding, but many of the company's grouts do.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Provoton Foam Concrete
  • Provoton Foam Concrete
  • Provoton
  • Provoton Foam Concrete
    Provoton
    Provoton foam concrete can be used for void fill, load reduction fill, or as a road sub-base and can be directly applied on marginal ground, such as peat or poor soils. Typical cast densities range from 25–55 pcf, with compressive strengths of 40–750 psi. At 30 pcf, the R-value is 1.35 per inch thick. According to the standard test method ASTM D 5084-90, Provoton maintains a low permeability of 1x10-5 cm/s. The company claims its protein-based blowing agent makes the hardened concrete resistant to insects and rodents and prevents breakdown due to hydrocarbons, bacteria, or fungi. A Cematrix authorized contractor is required for installation.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Allied Foamed Concrete
  • Allied Foamed Concrete
  • Allied Foam Tech
  • Allied Foamed Concrete
    Allied Foam Tech
    Allied Foam Concrete can be purchased in both pre-casted forms for blocks and panels, or poured directly for onsite applications, such as roof deck systems or in landscape architecture designs. The foamed cement is available at densities as low as 3 pcf (48 kg/m3) to as high as 90 pcf (1,450 kg/m3). At 3 pcf the foam fill has an R-value as high as 3.8 and at 29 pcf it can reach a compressive strength greater than 270 psi.
    Allied claims it can also adjust the ratio of open and closed pores to produce a targeted sound barrier or sound absorption panel.The company offers its own foam generating equipment, called the AFT G, that has a typical rate of production of 3–20 cfm.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Stable Air Insulating Cellular Concrete
  • Stable Air Insulating Cellular Concrete
  • Cullular Concrete Technologies
  • Stable Air Insulating Cellular Concrete
    Cullular Concrete Technologies
    Stable Air is an air entrainment system that produces lightweight cellular concrete for use in all ready-mix, precast, and prestress concrete products, including insulated roof panels. Effective in mixes with a high cement factor or with a low slump ratio, Stable Air has produced cement that weighs 120 lbs/ft3 (1922 kg/m3) and below. Cast densities from 30–147 pcf have compressive strengths ranging from 50–8,000 psi and have an average R-value of 1.82 per inch. The company claims to use one-third of the amount of material to produce the same amount of foam as its competitors because its concrete has a dilution rate of 1:120. Stable Air sells both portable and mounted foam generators that mix the foam to the right density.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • BubbleDeck Concrete Deck Systems
  • BubbleDeck Concrete Deck Systems
  • BubbleDeck North America LLC
  • BubbleDeck Concrete Deck Systems
    BubbleDeck North America LLC
    BubbleDeck uses a matrix of plastic spheres, steel reinforcement, and concrete that work together to form a “lightweight biaxial slab” that behaves like a solid concrete slab. The spheres act as voids and the concrete and steel that surround them essentially form “I-beams” in two directions. BubbleDeck can displace 25% or more of the concrete of a conventional deck, so its use can result in significant CO2 reduction as well as lighter decks that may require thinner columns or less foundation, resulting in further reductions in concrete use. This decking is prefabricated offsite, offering good quality control, before moving to the jobsite, where the remainder of the cement is added. When finished, BubbleDeck looks the same as conventional decking. BubbleDeck can be used in slabs ranging from 9 to 36 inches thick. The slabs are custom-engineered depending on the job but typical dimensions range from 8'–10' wide by 27'–45' long.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Caraustar Concrete Column Forms
  • Caraustar Concrete Column Forms
  • Caraustar ICPG Corp.
  • Caraustar Concrete Column Forms
    Caraustar ICPG Corp.
    Caraustar (formerly Smurfit) Concrete Column Forms are recycled-paper concrete forms with a polyethylene-impregnated virgin kraft interior layer (to aid release) and a waxed exterior. The recycled-paper content is estimated to be 90% from mixed, post-industrial, and post-consumer sources, according to the company. Caraustar Concrete Column Forms are available in a full range of diameters up to 60''.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Trojan Masonry Sealer
  • Trojan Masonry Sealer
  • Envirosafe Manufacturing Corporation
  • Trojan Masonry Sealer
    Envirosafe Manufacturing Corporation
    Trojan Masonry Sealer, a penetrating sealer for permanently waterproofing masonry, is a water-dispersed polyester polymer that dries to form a monolithic barrier filling voids and coating the interior particles of concrete to block moisture transmission. The product contains low levels of VOCs: 13.63 g/L. One gallon of Trojan Masonry Sealer can cover 200 ft2.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Armor S2000 Concrete Sealer
  • Armor S2000 Concrete Sealer
  • Foundation Armor
  • Armor S2000 Concrete Sealer
    Foundation Armor
    Armor S2000 is a sodium-silicate-based penetrating, strengthening concrete sealer with zero VOC content. Armor S2000 is intended for interior or exterior concrete, brick, and masonry; according to the manufacturer it is ideal for basements, where it provides waterproofing up to 100 PSI, prevents mold and mildew, and reduces the transmission of gases including radon. Applied with a garden sprayer, the product penetrates 4” into concrete, according to the company, and reacts with it, working under the surface to strengthen the substrate without leaving behind a coating. One gallon of Armor S2000 can provide two coats on 1,250 ft2 of new concrete, or 700 ft2 of old or porous concrete. It is also available in half-gallon containers, and carries a lifetime warranty.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Boost-R Panels
  • Boost-R Panels
  • Reward Wall Systems, Inc.
  • Boost-R Panels
    Reward Wall Systems, Inc.
    Reward Wall Sytems offers EPS panels designed to increase the R-value of insulating concrete forms (ICFs) manufactured by Reward. The 2"-thick panels are 48" x 16" and are custom ordered, so varying densities and thicknesses are available, as well as EPS with Neopor. A standard 1.5 lb/f3 panel will add R-8.34 to any standard ICF. To maintain the planned depth of concrete, the width of the ICF must be increased by 2" to compensate for the addition of the Boost-R panel. Special notches allow the panels to lock into place, and tapered edges allow for easy installation.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Atlas Finish-Film
  • Atlas Finish-Film
  • Atlas Construction Supply, Inc.
  • Atlas Finish-Film
    Atlas Construction Supply, Inc.
    Atlas Finish-Film is a water-based, low-VOC (less than 50 g/L) evaporation retarder for curing concrete. It produces a film on fresh concrete surfaces to prevent rapid moisture loss and allow for proper finishing, especially in hot, dry, or windy conditions.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Formula One Lithium Densifier
  • Formula One Lithium Densifier
  • L.M. Scofield Company
  • Formula One Lithium Densifier
    L.M. Scofield Company
    Scofield's Formula One Lithium Densifier MP is a zero-VOC lithium silicate densifier for ground and polished concrete surfaces. Formula One densifier reacts with calcium hydroxide in the concrete to produce calcium silicate hydrate, which hardens the surface.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • DiamondQuest Concrete Polishing System
  • DiamondQuest Concrete Polishing System
  • QuestMark Flooring, Division of Centimark Corp.
  • DiamondQuest Concrete Polishing System
    QuestMark Flooring, Division of Centimark Corp.
    QuestMark’s DiamondQuest concrete polishing system provides a protective sheen on concrete floors without the use of coatings. The multi-step process of progressively finer grinding is performed by QuestMark employees using the company's zero-VOC densifier, with dust controls that allow continued operation of the facility. The resulting floor is resistant to water and other contaminants and requires minimal maintenance.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • SureLock, ColorJuice, and Dye-N-Seal Concrete Colorants
  • SureLock, ColorJuice, and Dye-N-Seal Concrete Colorants
  • American Decorative Concrete
  • SureLock, ColorJuice, and Dye-N-Seal Concrete Colorants
    American Decorative Concrete
    American Decorative Concrete offers several concrete colorant products. Surelock Densi-Color combines dye with a densifier for application prior to diamond-polishing. Densi-Color, with VOC levels below 40 g/L, is intended for use with the zero-VOC SureLock Stain Protector. ColorJuice is a water-based silicate colorant for interior or exterior cured concrete; it is also available as a concrete sealer, with VOC levels below 40 g/L. For interior surfaces, Dye-N-Seal is a water-based dye with VOC levels below 4 g/L.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio