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    ASTM C946 - 18

    Standard Practice for Construction of Dry-Stacked, Surface-Bonded Walls

    Active Standard ASTM C946 | Developed by Subcommittee: C12.06

    Book of Standards Volume: 04.05

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    This practice covers material, workmanship, and construction procedures for applying surface bonded mortar to both sides of dry stacked concrete masonry units. Mortar shall be mixed and shall be selected in accordance with the proportion specification prescribed. Shims shall be corrosion-resistant metal or plastic with a required minimum compressive strength. Courses of concrete masonry units between the leveling courses shall be placed without mortar on the bed or head joints. Place units in running bond. Remove burrs and butt blocks tightly. Use shims, mortar, or surface bonding mortar to plum and level individual units when necessary. Use clean mixing equipment and water free of deleterious amounts of acid, alkali, and organic materials. Mix only full bag multiples of material to overcome any segregation of ingredients. Mixing time shall be kept to a minimum, as over mixing may cause damage to the fibers. Before applying surface bonding mortar, wet the wall uniformly with water to prevent excessive suction of water from the surface bonding mortar. Trowel- or spray-apply surface bonding mortar to both sides of dry-stacked concrete masonry units. When a second coat of surface bonding mortar is to be applied, the first coat shall have taken its initial set. Dampen the wall with a water mist after a specified time, but within a day of application of surface bonding mortar. The top of the walls shall be covered with a nonstaining, waterproof covering to prevent moisture from entering the wall until the top is permanently protected.

    This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

    1. Scope

    1.1 This practice covers material, workmanship, and construction procedures for applying surface bonded mortar to both sides of dry stacked concrete masonry units. It does not include grout, reinforcing, anchorage, or control joints since their use is essentially the same as conventional concrete masonry construction, unless specifically mentioned in this practice.

    Note 1: Design and construction procedures for conventional concrete masonry construction are found in Building Code Requirements for Masonry Structures (TMS 402-16) and Specification for Masonry Structures (TMS 602-16).

    1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

    1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

    1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    C55 Specification for Concrete Building Brick

    C90 Specification for Loadbearing Concrete Masonry Units

    C129 Specification for Nonloadbearing Concrete Masonry Units

    C270 Specification for Mortar for Unit Masonry

    C887 Specification for Packaged, Dry, Combined Materials for Surface Bonding Mortar

    Other Documents

    TEK 10-2C National Concrete Masonry Association, Control Joints for Concrete Masonry WallsEmpirical Method Available from the National Concrete Masonry Assn. (NCMA), 13750 Sunrise Valley Drive, Herndon, VA 20171, http://www.ncma.org.

    TMS402-16 The Masonry Society, Building Code Requirements for Masonry Structures Available from The Masonry Society, www.masonrysociety.org

    ICS Code

    ICS Number Code 91.060.10 (Walls. Partitions. Facades)

    UNSPSC Code

    UNSPSC Code 30111504(Mortars)

    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/C0946-18

    Citation Format

    ASTM C946-18, Standard Practice for Construction of Dry-Stacked, Surface-Bonded Walls, ASTM International, West Conshohocken, PA, 2018, www.astm.org

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