Whole Building Design Guide Federal Green Construction Guide for Specifiers 03400 - 1 http://fedgreenspecs.wbdg.org 11/02/05 Precast Concrete This is a guidance document with sample specification language intended to be inserted into project specifications on this subject as appropriate to the agency's environmental goals. Certain provisions, where indicated, are required for U.S. federal agency projects. Sample specification language is numbered to clearly distinguish it from advisory or discussion material. Each sample is preceded by identification of the typical location in a specification section where it would appear using the SectionFormatTM of the Construction Specifications Institute. SECTION 03400 - PRECAST CONCRETE SPECIFIER NOTE: resource management: Plant fabrication handles raw materials and by-products at a single location that typically allows greater efficiency and better pollution prevention than job site fabrication. Aggregates for use in concrete include normal sand and gravel, crushed stone, expanded clay, expanded shale, expanded slate, pelletized or extruded fly ash, expanded slag, perlite, vermiculite, expanded polystyrene beads, or processed clay, diatomite, pumice, scoria, or tuff. Architectural items (planters, lintels, bollards) fabricated from lightweight and recycled content aggregates are available. The quantity and type of recycled materials vary from manufacturer to manufacturer and include: cellulose, fiberglass, polystyrene, and rubber. Autoclaved aerated concrete (AAC) is a type of lightweight precast concrete prevalent in Europe, Asia, and the Middle East and recently available through manufacturing facilities in the United States. It is made with portland cement, silica sand or fly ash, lime, water, and aluminum powder or paste. The aluminum reacts with the products of hydration to release millions of tiny hydrogen gas bubbles that expand the mix to approximately five times the normal volume. When set, the AAC is cut into blocks or slabs and steam-cured in an autoclave. toxicity/IEQ: Refer to Section 03300 - Cast-In-Place Concrete. Precast concrete generally requires less portland cement per volume of concrete for similar performance due to better quality control. performance: Performance is more predictable in precast operations since more exact dimensions, placement of reinforcing, and surface finishing can be obtained. Precast concrete can be fabricated with continuous insulation. AAC is significantly lighter (about 1/5th the weight of traditional concrete) than normal concrete and can be formed into blocks or panels. Lighter weight concretes generally have greater fire and thermal resistance but less strength than traditional normal weight concrete. A full range of lightweight concretes are available and their strength and weight is determined by the aggregates used. PART 1 - GENERAL 1.1 SUMMARY A. This Section includes: 1. Autoclaved Aerated Concrete (AAC). B. Related Sections: 1. Section 03300 – Cast-In-Place Concrete. 1.2 SUBMITTALS A. Product data. Unless otherwise indicated, submit the following for each type of product provided under work of this Section: SPECIFIER NOTE:Whole Building Design Guide Federal Green Construction Guide for Specifiers 03400 - 2 http://fedgreenspecs.wbdg.org 11/02/05 Precast Concrete Green building rating systems often include credit for materials of recycled content. USGBC-LEED™ v2.2, for example, includes credit for materials with recycled content, calculated on the basis of pre-consumer and post-consumer percentage content and it includes credit for use of salvaged/recovered materials. Green Globes US also provides points for reused building materials and components and for building materials with recycled content. 1. Recycled Content: a. Indicate recycled content; indicate percentage of pre-consumer and post-consumer recycled content per unit of product. b. Indicate relative dollar value of recycled content product to total dollar value of product included in project. c. If recycled content product is part of an assembly, indicate the percentage of recycled content product in the assembly by weight. d. If recycled content product is part of an assembly, indicate relative dollar value of recycled content product to total dollar value of assembly. SPECIFIER NOTE: Specifying local materials may help minimize transportation impacts; however it may not have a significant impact on reducing the overall embodied energy of a building material because of efficiencies of scale in some modes of transportation. Green building rating systems frequently include credit for local materials. Transportation impacts include: fossil fuel consumption, air pollution, and labor. USGBC-LEED™ v2.2 includes credits for materials extracted/harvested and manufactured within a 500 mile radius from the project site. Green Globes US also provides points for materials that are locally manufactured. 2. Local/Regional Materials: a. Sourcing location(s): Indicate location of extraction, harvesting, and recovery; indicate distance between extraction, harvesting, and recovery and the project site. b. Manufacturing location(s): Indicate location of manufacturing facility; indicate distance between manufacturing facility and the project site. c. Product Value: Indicate dollar value of product containing local/regional materials; include materials cost only. d. Product Component(s) Value: Where product components are sourced or manufactured in separate locations, provide location information for each component. Indicate the percentage by weight of each component per unit of product. B. Submit environmental data in accordance with Table 1 of ASTM E2129 for products provided under work of this Section. C. Documentation of manufacturer’s take-back program for [units, full and partial] [packaging] [xxxx]. Include the following: 1. Appropriate contact information. 2. Overview of procedures. a. Indicate manufacturer’s commitment to reclaim materials for recycling and/or reuse. 3. Limitations and conditions, if any, applicable to the project. PART 2 - PRODUCTS 2.1 MATERIALS A. Load bearing and non-lad-bearing AAC elements: Comply with ASTM C1386.Whole Building Design Guide Federal Green Construction Guide for Specifiers 03400 - 3 http://fedgreenspecs.wbdg.org 11/02/05 Precast Concrete PART 3 - EXECUTION 3.X SITE ENVIRONMENTAL PROCEDURES A.
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