ASTM WK75815

    Revision of C140 / C140M - 20a Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units

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    Active Standard: C140 / C140M - 20a

    Developed by Subcommittee: C15.03 | Committee C15 | Contact Staff Manager



    absorption; compressive strength; concrete masonry units; density; equivalent thickness; face shell; moisture content; roof paver; web area; webs; web thickness;;


    ASTM C140 currently contains conditioning requirements for paving slabs in Annex A8. Similar (but not the same) requirements exist in ASTM C1645 (freeze-thaw durability testing standard) as well as CSA A231.1 & 2 (Canadian standard for pavers and slabs). The intent of this ballot is to harmonize these requirements as much as possible between the standards. Technical changes include: Changing moist curing time from 28 +/- 1 day to 14 +/- 1 days Changing moist curing temperature in Fahrenheit from 73 +/- 3 degrees to 73 +/- 4 degrees Changing air curing time from 3 to 7 days to a minimum of 14 days Changing air curing temperature from 73 +/- 3 F [23 +/- 2 C] to 75 +/- 15 F [24 +/- 8 C] Changing air curing relative to humidity from only minimum 40% to a range from 40 to 80% oThese last two changes make the air curing conditions consistent with general conditioning requirements in ASTM C140 In addition to the changes to requirements above, the ballot reorganizes the conditioning requirements for clarity.

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    Work Item Status

    Date Initiated:

    Technical Contact:
    Craig Walloch


    C15 (21-01)

    On Hold