AASHTO T 131:2014 Standard Method of Test for Time of Setting of Hydraulic Cement by Vicat Needle.
4 SUMMARY OF TEST METHOD
4.1 A paste that is proportioned and mixed to normal consistency, as described in the test method T 129. is molded and placed in a moist cabinet and allowed to start setting. Periodic penetration tests are performed on this paste by allowing a 1-mm Vicat needle to settle into this paste. The Vicat initial time of setting is calculated as the time elapsed between the initial contact of cement and water and the time when the penetration is at 25 mm. The Vicat final time of setting is calculated as the time when the needle does not sink visibly into the paste.
5 SIGNIFICANCE AND USE
5.1 This test method provides a means of determining compliance with a specification limit for Vicat time of setting. Refer to the appropriate specification for the cement to determine if this test method is used for specification compliance.
5.2. The measured time of setting is affected by the percentage and temperature of the water used, the amount of kneading the paste received, and by the temperature and humidity of the mixing room air and the moist cabinet or moist room air.
5.3. The measured time of setting of hydraulic cement is test-method specific. Time of setting as measured by this method will not necessarily be similar to other methods used for determining the time of setting of hydraulic cements.
Vical Apparatus—See Annex A I . I and Figure A I .1. The Vicat apparatus for this test method shall have a movable rod. B, of mass 300 ± 0.5 g.
6.1.1. The end of the rod used for measuring penetration shall have a removable needle, D, with a diameter of 1.00 ± 0.05 mm and length no less than 50 mm.
6.1.2. The needle end that contacts the specimen shall be flat, plane, and at right angles to the axis of the rod.
9.4. The moist closet or moist room shall be in accordance with M 201.
10. PREPARATION OF CEMENT PASTE
10.1. The cement paste used for the determination of the time of setting is obtained from one of the following methods:
10.1.1. Prepare a new batch of paste by mixing 650 g of cement with the percentage of mixing water required for normal consistency (T 129), following the procedure described in T 162.
10.1.2. For Method A. at the option of the tester, use the test specimen used for determining normal consistency (Note 2).AASHTO T 131 pdf download.