Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance
The resistance of the concrete mixture to penetration by standard needles is measured. The initial and final setting times are determined from a plot of penetration resistance versus time. A sample of at least 25 lbs. should be submitted.
Since the setting of concrete is a gradual process, any definition of time of setting must necessarily be arbitrary. In this test method, the times required for the mortar to reach specified values of resistance to penetration are used to define times of setting.
This test method can be used to determine the effects of variables, such as water content; brand, type and amount of cementitious material; or admixtures, upon the time of setting of concrete. This test method may also be used to determine compliance with specified time-of-setting requirements.
This test method may also be applied to prepared mortars and grouts. However, when the setting time of concrete is desired, the test shall be performed on mortar sieved from the concrete mixture and not on a prepared mortar intended to simulate the mortar fraction of the concrete; it has been shown that the initial and final setting times may be increased when using the prepared mortar.
1.1 This test method covers the determination of the time of setting of concrete, with slump greater than zero, by means of penetration resistance measurements on mortar sieved from the concrete mixture.
1.2 This test method is suitable for use only when tests of the mortar fraction will provide the information required.
1.3 This test method may also be applied to prepared mortars and grouts.
1.4 This test method is applicable under controlled laboratory conditions, as well as under field conditions.
Extracted, with permission, from ASTM C403 / C403M Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the standard may be purchased from ASTM International, phone 610-832-9555, e-mail: firstname.lastname@example.org, website: www.astm.org.
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