LEED includes specific rating systems for various applications. The inert nature of concrete masonry lends itself well to incorporating recycled materials as cement replacements, as aggregates and as other constituents in the concrete mix. This TEK provides guidance on determining the recycled content of concrete masonry products for the purpose of earning LEED credit under the new construction, school, retail, and core and shell development LEED programs.
Note, however, that the National Association of Home Builders with the International Code Council has developed their own green building standard that has similar requirements ref. When concrete masonry products incorporate recycled materials, due consideration must be given to ensure that the use of these materials does not adversely affect the quality or safety of the units or construction. Note that some recycled materials may only be regionally available.
Designers should work closely with concrete masonry manufacturers to substantiate recycled content. Whether produced using recycled or virgin materials, concrete masonry products are required to meet the applicable ASTM unit specification see Table 1.
These standards contain minimum requirements that assure properties necessary for quality performance. ASTM C90 requirements include material requirements for aggregates, cementitious materials, and other constituent materials, physical requirements, finish and appearance requirements, and permissible variations in dimensions. Aggregate characteristics governed include limits on deleterious substances and aggregate soundness.
For a material to qualify for inclusion in a concrete masonry product under this provision, the material:.
For construction requiring a fire resistance rating, the use of recycled aggregates may impact the method used to determine the hourly rating, because concrete masonry fire resistance ratings vary with the aggregate type s used to manufacture the units. Concrete masonry fire ratings can be determined by: model building code prescriptive tables ref.
Currently, the standard calculation procedure applies to the following aggregate types: expanded slag, pumice, expanded clay, expanded shale, expanded slate, limestone, cinders, air-cooled slag, calcareous gravel, and siliceous gravel. When units are made with a combination of these aggregates, the fire rating is determined by interpolation see ref. When aggregate types other than those listed above are used, the fire resistance rating is determined using a method other than the standard calculation procedure.
Additional considerations for recycled aggregates which are not listed in the standard calculation procedure are their stability, safety and load-carrying ability when subjected to fire. By increasing the demand for products that incorporate recycled materials, the Recycled Content credits are intended to reduce the environmental and societal impacts associated with extracting and processing virgin materials.
LEED refers to the International Organization for Standardization ISO for the definition of what constitutes recycled content, and for the basis of determining the percentage — i. Recycled materials are those materials diverted from the solid waste stream, either during the manufacturing process pre-consumer or after their intended use post-consumer. Few categories of bricks are sellable while few are apt only for small, non-load bearing works or grinding up to manufacture new bricks.
Recycled bricks can be the perfect construction material for a lot of projects. The weathered look that old, reused bricks provide is almost impossible to get artificially.
Thus recycled bricks are in a great demand in places where the antique and worn look is required. Apart from this, reclaimed bricks are also used in new construction projects, remodeling projects, small building projects, fireplaces, walls or boundaries. Reclaimed bricks can also be used while constructing walkways, landscaping projects, patios or creating artistic projects. If the bricks are in extremely poor shape but still have recycled life left in them, they can be broken down into aggregate, can be made into new bricks, or can be used as a base compound in ground surfaces such as tennis court.
There are limitless ways in which the bricks can be recycled. Still, unlike poured concrete slabs, steps, and wood elements, bricks are only limited by how they are positioned. Though it may be difficult to recycle some wood or concrete steps, the options are pretty limitless for bricks. The brick manufacturing process uses a lot of energy, materials, and even some harmful materials. When bricks are recycled, this cuts down on the need for unnecessary waste in this manufacturing process.
Try as hard as we like to recreate the look of a historic home, building, wall, or walkway, it will always lack the character of a genuinely historic building. Bricks are still vital to construction , but they require kiln energy to make and are strangely unrecycleable. Like a cake pop, the new bricks involve combining broken up bricks and a pasty binder. After thousands of years, is the new brick worth a try? More Stuff You'll Love.
Caroline Delbert Caroline Delbert is a writer, book editor, researcher, and avid reader.
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