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    Aggregate Crushing Value

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    kausik nath
    The aggregate crushing value test determines the resistance of an aggregate sample to crushing by gradually applying a compressive load. The test involves weighing an aggregate sample passing a 12.5mm sieve and retained on a 10mm sieve, then placing it in a cylinder apparatus and applying a 400kN load over 10 minutes. The crushed material is then sieved and weighed, and the aggregate crushing value is calculated as the percentage of fines passing a 2.36mm sieve relative to the original sample weight. The result indicates the aggregate's resistance to crushing under load.

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    Aggregate Crushing Value

    Uploaded by

    kausik nath
    413 views2 pages
    The aggregate crushing value test determines the resistance of an aggregate sample to crushing by gradually applying a compressive load. The test involves weighing an aggregate sample passing a 12.5mm sieve and retained on a 10mm sieve, then placing it in a cylinder apparatus and applying a 400kN load over 10 minutes. The crushed material is then sieved and weighed, and the aggregate crushing value is calculated as the percentage of fines passing a 2.36mm sieve relative to the original sample weight. The result indicates the aggregate's resistance to crushing under load.

    Original Description:

    Aggregate Crushing Value (ballast)

    Original Title

    Aggregate Crushing Value (1)

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    The aggregate crushing value test determines the resistance of an aggregate sample to crushing by gradually applying a compressive load. The test involves weighing an aggregate sample passing a 12.5mm sieve and retained on a 10mm sieve, then placing it in a cylinder apparatus and applying a 400kN load over 10 minutes. The crushed material is then sieved and weighed, and the aggregate crushing value is calculated as the percentage of fines passing a 2.36mm sieve relative to the original sample weight. The result indicates the aggregate's resistance to crushing under load.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    413 views2 pages

    Aggregate Crushing Value

    Uploaded by

    kausik nath
    The aggregate crushing value test determines the resistance of an aggregate sample to crushing by gradually applying a compressive load. The test involves weighing an aggregate sample passing a 12.5mm sieve and retained on a 10mm sieve, then placing it in a cylinder apparatus and applying a 400kN load over 10 minutes. The crushed material is then sieved and weighed, and the aggregate crushing value is calculated as the percentage of fines passing a 2.36mm sieve relative to the original sample weight. The result indicates the aggregate's resistance to crushing under load.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
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    of 2

    AGGREGATE CRUSHING VALUE

    1. Objective
    The aggregate crushing value gives a relative measure of the resistance of an aggregate to crushing
    under a gradually applied compressive load. With aggregate of aggregate crushing value 30 or higher,
    the result may be anomalous, and in such cases the ten percent fines value should be determined
    instead.

    2. Apparatus Required

    Fig. 1: Balance

    Balance should be accurate upto 1 gm.

    Fig. 2: Sieve (12.5 mm, 10.0 mm and 2.36 mm)

    Fig. 3: Mould, Measuring Cylinder with Plunger

    15-cm diameter open-ended steel cylinder, with plunger and base-plate, of the
    general form and dimensions and a straight metal tamping rod. For measuring
    the sample, cylindrical metal measure of sufficient rigidity to retain its form
    under rough usage and of the following internal dimensions: Diameter 11.5 cm
    and Height 18.0 cm

    3. Reference
    IS 2386(Part 4):1963 Methods of Test for Aggregates for Concrete- Mechanical Properties. Reaffirmed-
    Dec 2016

    4. Procedure
    1. The material for the standard test shall consist of aggregate passing a 12.5 mm IS Sieve and
    retained on a 10 mm IS Sieve, and shall be thoroughly separated on these sieves before testing.
    2. The aggregate shall be tested in a surface-dry condition. If dried by heating, the period of drying
    shall not exceed four hours, the temperature shall be 100 to 110°C and the aggregate shall be cooled
    to room temperature before testing.
    3. The appropriate quantity may be found conveniently by filling the cylindrical measure in three layers
    of approximately equal depth, each layer being tamped 25 times with the rounded end of the
    tamping rod and finally leveled off, using the tamping rod as a straight-edge.
    4. The weight of material comprising the test sample shall be determined (Weight A) and the same
    weight of sample shall be taken for the repeat test.
    5. The cylinder of the test apparatus shall be put in position on the base plate and the test sample
    added in thirds, each third being subjected to 25 strokes from the tamping rod. The surface of the
    aggregate shall be carefully levelled and the plunger inserted so that it rests horizontally on this
    surface, care being taken to ensure that the plunger does not jam in the cylinder.
    6. The apparatus, with the test sample and plunger in position, shall then be placed between the
    platens of the testing machine and loaded at as uniform a rate as possible so that the total load is
    reached in 10 minutes. The total load shall be 400 kN.
    7. The load shall be released and the whole of the material removed from the cylinder and sieved on a
    2.36 mm IS Sieve for the standard test. The fraction passing the sieve shall be weighed (Weight B).
    5. Calculation
    1. The ratio of the weight of fines formed to the total sample weight in each test shall be expressed as a
    percentage, the result being recorded to the first decimal place:

    Aggregate Crushing Value = (B/A) X 100

    where A = weight of oven-dried sample


    B = weight in 'g' of fraction passing through 2.36 mm IS sieve.

    6. Video
    Aggregate Crushing Value Test

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