1、Designation: C191 08C191 13 American Association StateHighway and Transportation Officials StandardAASHTO No.: T131Standard Test Methods forTime of Setting of Hydraulic Cement by Vicat Needle1This standard is issued under the fixed designation C191; the number immediately following the designation i
2、ndicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods determine the time
3、of setting of hydraulic cement by means of the Vicat needle. Two test methods aregiven; MethodAis the Reference Test Method using the manually operated standard Vicat apparatus, while Method B permits theuse of an automatic Vicat machine that has, in accordance with the qualification requirements of
4、 this method, demonstratedacceptable performance.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 responsi
5、bilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. See 1.4 for a specific warning statement.1.3 This standard does not purport to address all of the safety concerns, if any, associated with it
6、s use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.WarningWarning:Fresh Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissu
7、eupon prolonged exposure.The use of gloves, protective clothing, and eye protection is recommended. Wash contact area withcopious amounts of water after contact. Wash eyes for a minimum of 15 min. Avoid exposure of the body to clothing saturatedwith the liquid phase of the unhardened material. Remov
8、e contaminated clothing immediately after exposure.21.4 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.NOTE 1For the method for deter
9、mining the time of setting by Gillmore needles, see Test Method C266.2. Referenced Documents2.1 ASTM Standards:3C150 Specification for Portland CementC151 Test Method for Autoclave Expansion of Hydraulic CementC183 Practice for Sampling and the Amount of Testing of Hydraulic CementC187 Test Method f
10、or Amount of Water Required for Normal Consistency of Hydraulic Cement PasteC219 Terminology Relating to Hydraulic CementC266 Test Method for Time of Setting of Hydraulic-Cement Paste by Gillmore NeedlesC305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
11、C511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of HydraulicCements and ConcretesC595 Specification for Blended Hydraulic CementsC1005 Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical
12、Testing ofHydraulic CementsC1157 Performance Specification for Hydraulic CementD1193 Specification for Reagent Water1 These test methods are under the jurisdiction of ASTM Committee C01 on Cement and is the direct responsibility of Subcommittee C01.30 on Time of Set.Current edition approved June 1,
13、2008Dec. 1, 2013. Published July 2008January 2014. Originally approved in 1944. Last previous edition approved in 20072008 asC191 07.C191 08. DOI: 10.1520/C0191-08.10.1520/C0191-13.2 Section on Safety, Manual of Cement Testing, Annual Book of ASTM Standards, Vol 04.01.3 For referencedASTM standards,
14、 visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM st
15、andard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by A
16、STM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 DefinitionsThe terms used in this test method are defined
17、 in accordance with Terminology C219.4. Summary of Test Method4.1 A paste that is proportioned and mixed to normal consistency, as described in the Test Method C187, is molded and placedin a moist cabinet and allowed to start setting. Periodic penetration tests are performed on this paste by allowin
18、g a 1-mm Vicatneedle to settle into this paste. The Vicat initial time of setting is the time elapsed between the initial contact of cement and waterand the time when the penetration is measured or calculated to be 25 mm.TheVicat final time of setting is the time elapsed betweeninitial contact of ce
19、ment and water and the time when the needle does not leave a complete circular impression in the paste surface.5. Significance and Use5.1 This test method provides a means of determining compliance with a specification limit for Vicat time of setting. Refer tothe appropriate specification for the ce
20、ment to determine if this test method is used for specification compliance.5.2 Time of setting measured by this method will not necessarily provide the same results as the time of setting of hydrauliccement paste measured by other methods, or the time of setting of mortar or concrete.6. Apparatus6.1
21、 Vicat ApparatusSee Annex A1.1 and Fig. A1.1. The Vicat apparatus for this test method shall have a movable rod, B, ofmass 300 6 0.5g.6.1.1 The end of the rod used for measuring penetration shall have a straight steel removable needle with a diameter of 1.006 0.05 mm and length no less than 50 mm.6.
22、1.2 The needle end that contacts the specimen shall be flat, plane, and at right angles to the axis of the rod.6.2 Reference Masses and Devices for Determining Mass, conforming to the requirements of Specification C1005. The devicesfor determining mass shall be evaluated for precision and accuracy a
23、t a total load of 1000 g.6.3 Glass Graduates, 200 or 250-mL capacity, and conforming to the requirements of Specification C1005.6.4 Plane non-adsorptive plate, 100 6 5 mm square of similar planeness, corrosivity, and absorptivity to that of glass (seeAnnex A1.1, Fig. A1.1, H).6.5 Flat trowel, having
24、 a sharpened straight-edged steel blade 100 to 150 mm in length. The edges when placed on a planesurface shall not depart from straightness by more than 1 mm.6.6 Conical ring, made of a rigid, non-corroding, non-absorbent material and having a height of 40 6 1 mm, an inside diameterat the bottom of
25、70 6 3 mm, and an inside diameter at the top of 60 6 3 mm (see Annex A1.1, Fig. A1.1, G).6.7 Mixer, bowl, and paddle, conforming to Practice C305.6.8 Automatic Vicat Needle Apparatus for Method BThe apparatus shall be equipped with a Vicat needle as described in 6.1.1and 6.1.2. The total mass suppor
26、ted by the needle tip at the time of measurement shall be 300 6 0.5 g. The instrument shall becapable of automatically completing and recording penetration measurements of a test specimen at predetermined time intervalsnot exceeding 10 min and make each penetration test at least 5 mm away from any p
27、revious penetration and at least 10 mm awayfrom the inner side of the mold.6.9 Specimen Mold for Method BThe cement paste is held in a conical ring with the height of 40 6 1 mm and a removablebase plate. The test surface shall have a minimum diameter of 60 6 3 mm.6.10 Inspect and document Section 6
28、apparatus for conformance to the requirements of this test method at least every 2 12 years.7. Reagents and Materials7.1 Mixing WaterPotable water is satisfactory for routine tests. Use water conforming to the requirements of SpecificationD1193 for Type III or Type IV grade reagent water for all ref
29、eree and cooperative tests.8. Sampling8.1 When the test is required for acceptance testing, sample cement in accordance with Practice C183.9. Conditioning9.1 Maintain the temperature of the air in the vicinity of the mixing slab, the dry cement, molds, and base plates at 23.0 6 3.0C.9.2 Maintain the
30、 temperature of the mixing water at 23.0 6 2.0 C.9.3 The relative humidity of the mixing room shall be not less than 50 %.C191 1329.4 The moist cabinet or moist room shall be in accordance with Specification C511.10. Preparation of Cement Paste410.1 The cement paste used for the determination of the
31、 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 normalconsistency (Test Method C187), following the procedure described in Practice C305.10.1.2 For method A, at the option of
32、 the tester, use the test specimen used for determining normal consistency (see Note 2).10.1.3 At the option of the tester, use the paste remaining from the batch used for the autoclave specimen (Test Method C151)or from the normal consistency determination (Test Method C187).NOTE 2The specimen used
33、 for the determination of the normal consistency will have an irregular surface, making it unsuitable for method B.11. Calculation11.1 Calculate the Vicat time of setting to the nearest 1 min as follows:SSH 2E!C2D!D 3C 225!D1E (1)where:E = time in minutes of last penetration greater than 25 mm,H = t
34、ime in minutes of first penetration less than 25 mm,C = penetration reading at time E, andD = penetration reading at time H.11.2 Calculate the Vicat final time of setting by determining the elapsed time between the time of the initial contact betweencement and water and the time when the needle does
35、 not sink visibly into the paste, rounded to the nearest 5 min.12. Report12.1 Report the time of setting and the method used as follows:Vicat time of setting (A or B) _ minVicat final time of setting (A or B) _ minMethod AManual Vicat Needle Apparatus13. Manual Vicat Apparatus13.1 Refer to the Appar
36、atus section, paragraphs 6.1, 6.4, and 6.6, and Annex A1 for a description of the Vicat apparatus.14. Procedure A14.1 Molding Test SpecimenQuickly form the cement paste, prepared as described in the section on preparation of cementpaste, into a ball with gloved hands and toss six times from one hand
37、 to the other, maintaining the hands about 150 mm (6 in.)apart. Press the ball, resting in the palm of the hand, into the larger end of the conical ring, G,Fig. A1.1, held in the other hand,completely filling the ring with paste. Remove the excess at the larger end by a single movement of the palm o
38、f the hand. Placethe ring on its larger end onto the non-absorptive plate, H, and slice off the excess paste at the smaller end at the top of the ringby a single oblique stroke of the trowel held at a slight angle with the top of the ring. Smooth the top of the specimen, if necessary,with one or two
39、 light touches of the pointed end of the trowel. During the operation of cutting and smoothing, take care not tocompress the paste. Immediately after molding, place the test specimen in the moist cabinet or moist room and allow it to remainthere except when penetration measurements are being made. T
40、he specimen shall remain in the conical mold, supported by thenon-absorptive plate throughout the test period.14.2 Time of Setting DeterminationAllow the time of setting specimen to remain in the moist cabinet or moist room for 30min after molding without being disturbed. Determine the penetration o
41、f the 1-mm needle at this time and every 15 min thereafter(every 10 min for Type III cements) until a penetration of 25 mm or less is obtained. Perform the penetration test by lowering theneedle D of the rod B until it rests on the surface of the cement paste. Tighten the setscrew, E, and set the in
42、dicator, F, at the upperend of the scale, or take an initial reading. Release the rod quickly by releasing the set screw, E, and allow the needle to settle for30 s; then take the reading to determine the penetration. At the option of the tester, if the paste is obviously quite soft on the earlyreadi
43、ngs, retard the fall of the rod to avoid bending the 1-mm needle, but when actual penetration measurements to determine thetime of setting are made, release the rod only by the setscrew. Make each penetration test at least 5 mm away from any previouspenetration and at least 10 mm away from the inner
44、 side of the mold. Record the results of all penetration tests and, by4 See Test Method C187.C191 133interpolation, determine the time when a penetration of 25 mm is obtained. The elapsed time between the initial contact of cementand water and the penetration of 25 mm is the Vicat time of setting or
45、 Vicat initial time of setting.14.3 Determine the Vicat final time of setting end point to be the first penetration measurement that does not mark the specimensurface with a complete circular impression. Verify final set by performing two additional penetration measurements on differentareas of the
46、specimen surface. Obtain verification measurements within 90 s of the first “final set” measurement. The elapsed timebetween the initial contact of cement and water and the end point determination above is the Vicat final time of setting.14.4 PrecautionsKeep all the apparatus free from vibration dur
47、ing the penetration test. Keep the 1-mm needle straight andclean. The needle must be kept clean to prevent cement from adhering to the sides of the needle and decreasing penetration, andto prevent cement from adhering to the point and increasing penetration.15. Precision and Bias15.1 Precision:15.1.
48、1 The single-operator (within-laboratory) standard deviation has been found to be 12 min for the initial time of setting,throughout the range of 49 to 202 min, and 20 min for the final time of settings throughout the range of 185 to 312 min. Therefore,results of two properly conducted tests by the s
49、ame operator on Vicat initial time of setting of similar paste should not differ fromeach other by more than 34 min and on Vicat final time of setting of similar pastes should not differ from each other by more than56 min.15.1.2 The multilaboratory (between-laboratory) standard deviation has been found to be 16 min for the initial time of settingthroughout the range of 49 to 207 min, and 43 min for the final time of setting throughout the range of 185 to 312 min. Therefore,results of two properly conducted tests from two different laboratories on Vi
