ASTM C266-2018 pdf free download

ASTM C266-2018 pdf free download.Standard Test Method for Time of Setting of Hydraulic-Cement Paste by Gillmore Needles
1. Scope
1.1 This test method covers the determination of the time of setting of hydraulic-cement paste by means of the Gillmore needles. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 appro- priate safety and health practices and determine the applica- bility ofregulatory limitations prior to use. Warning: Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure. 2 1.4 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Summary of Test Method
4.1 Sufficient water is added to the cement that is being tested to produce a paste of normal consistency. A specimen is molded from this paste and is tested for time of setting by means of the Gillmore initial and final needles. The initial time of setting is the time elapsed between initial contact of cement and water and the time when the Gillmore Initial needle does not leave a complete circular impression in the paste surface. The final time of setting is the time elapsed between initial contact of cement and water and the time when the Gillmore Final needle does not leave a complete circular impression in the paste surface.
10. Procedure
10.1 Preparation ofCement Paste: Obtain the cement paste used for determination of the time of setting 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 (Test Method C187), following the proce- dure described in Practice C305. 10.1.2 At the option of the tester, use the paste remaining from the batch used for the autoclave expansion specimen (Test Method C151/C151M) or from the normal consistency deter- mination (Test Method C187). 10.2 Molding Test Specimen—From the cement paste pre- pared as described in 10.1, make a pat with a flat top and the sides tapering to a thin edge on a plane non-absorptive plate, conforming to the dimensions and tolerances in Fig. 1 (a). In molding the pat, flatten the cement paste first on the plate and then form the pat by drawing the trowel from the outer edge toward the center, then flattening the top. After making, place the pat in the moist cabinet or moist room and allow it to remain there except when the determinations of time of setting are being made. 10.3 Time ofSetting Determination—Determine the time of setting by holding the needle in a vertical position and lightly applying it to the surface of the pat. 10.3.1 Using the Initial Gillmore needle, determine the Gillmore Initial time of setting end point to be the first penetration measurement that does not mark the specimen surface with a complete circular impression. Verify Initial set by obtaining two additional penetration measurements on different areas of the specimen surface. Verification measure- ments must be obtained within 90 s of the first “initial set” measurement. The elapsed time, in minutes, between the time of contact of cement and mixing water and the end point determined above is the Gillmore initial time of setting. 10.3.2 Using the Final Gillmore needle, determine the Gillmore Final time of setting end point to be the first penetration measurement that does not mark the specimen surface with a complete circular impression. Verify Final set by obtaining two additional penetration measurements on different areas of the specimen surface. Verification measurements must be obtained within 90 s of the first “final set” measurement. The elapsed time, in minutes, between the time of contact of cement and mixing water and the end point determined above is the Gillmore final time of setting.