1、Designation: C 827 01a (Reapproved 2005)Standard Test Method forChange in Height at Early Ages of Cylindrical Specimens ofCementitious Mixtures1This standard is issued under the fixed designation C 827; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This
3、 test method covers the determination of change inheight of cylindrical specimens from the time of molding untilthe mixture is hard.1.2 This test method covers height change measurements atearly ages for cementitious mixtures of paste, grout, mortar,and concrete.1.3 This test method is intended for
4、determination ofchanges in height that occur from the time of placement untilthe specimen is fully hard. These include shrinkage or expan-sion due to hydration, settlement, evaporation, and otherphysical and chemical effects.1.4 The values stated in SI units are to be regarded as thestandard.1.5 Thi
5、s standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.6 The text of this t
6、est method references notes andfootnotes that provide explanatory information. These notesand footnotes shall not be considered as requirements of thetest method.2. Referenced Documents2.1 ASTM Standards:2C 109/C 109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50
7、-mm CubeSpecimens)C 125 Terminology Relating to Concrete and ConcreteAggregatesC 138/C 138M Test Method for Density (Unit Weight),Yield, and Air Content (Gravimetric) of ConcreteC 143/C 143M Test Method for Slump of Hydraulic-Cement ConcreteC 185 Test Method for Air Content of Hydraulic CementMortar
8、C 191 Test Method for Time of Setting of Hydraulic Ce-ment by Vicat NeedleC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC 403/C 403M Test Method for Time of Setting
9、of ConcreteMixtures by Penetration ResistanceC 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC 807 Test Method for Time of Setting of Hydraulic Ce-ment Mortar by Modified Vicat NeedleC 939 Test Method for Flow of Grout for Preplaced-Aggregate Conc
10、rete (Flow Cone Method)C 953 Test Method for Time of Setting of Grouts forPreplaced-Aggregate Concrete in the LaboratoryC 1437 Test Method for Flow of Hydraulic Cement Mortar3. Terminology3.1 DefinitionsThe terms used in this test method aredefined in Terminology C 125.3.2 Definitions of Terms Speci
11、fic to This Standard:3.2.1 early-age change in height, nthe measured increaseor decrease in height of a laterally confined cylindrical testspecimen from the time of molding to when the mixturebecomes hard. The user may want to define this age as the timewhen a companion specimen of the same batch ha
12、s reached thetime of final setting by Test Method C 191 (paste), C 953(mortar or grout), C 403/C 403M (concrete), or establish apredetermined age in minutes from the time the specimen iscast as the defined age to record the final measurement.1This test method is under the jurisdiction of ASTM Commit
13、tee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.68 on Volume Change.Current edition approved July 1, 2005. Published August 2005. Originallyapproved in 1975. Last previous edition approved in 2001 as C 827 01a.2For referenced ASTM standards, visit the A
14、STM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Uni
15、ted States.Changes in height are measured and expressed as a positive ornegative change in the height of a test specimen that isrestrained from lateral movement.4. Significance and Use4.1 This test method provides a means for comparing therelative shrinkage or expansion of cementitious mixtures. It
16、isparticularly applicable to grouting, patching, and form-fillingoperations where the objective is to completely fill a cavity orother defined space with a freshly mixed cementitious mixturethat will continue to fill the same space at time of hardening. Itwould be appropriate to use this test method
17、 as a basis forprescribing mixtures having restricted or specified volumechange before the mixture becomes hard.4.2 This test method can be used for research purposes toprovide information on volume changes taking place in cemen-titious mixtures between the time just after mixing and the timeof hard
18、ening. However, the specimen used in this test methodis not completely unrestrained so that the measurements areprimarily useful for comparative purposes rather than asabsolute values. Further, the degree of restraint to which thespecimen is subjected varies with the viscosity and degree ofhardening
19、 of the mixture.5. Apparatus (see Fig. 1)5.1 Projected Light Source, a lamp and a condensing lens ofsufficient intensity to adequately project a light beam on a wallabout 5 m (15 ft) from the light source. Protect the testspecimen from heat from the light source and limit airmovement (Note 1).NOTE 1
20、Placing a sheet of transparent glass or plastic between thelight source and the test specimens may be beneficial.5.2 Indicator Ball, a spherical ball of nonabsorptive mate-rial with a density that is 55 6 5 % of the density of thecementitious mixture being tested, having a diameter not morethan 16 m
21、m (58 in.) nor less than 6 mm (14 in.), and composedof materials that have no reaction with the cementitiousmixture during the test period.3NOTE 2A density of approximately 1.2 Mg/m3has been foundappropriate for most uses of this test method. The density of thecementitious mixture may be calculated
22、from values for “unit weight”obtained using Test Method C 138/C 138M (concrete) or C 185 (mortar,grout, or paste).5.3 Magnifying Lens System, a magnifying lens system suchthat the image of the indicator ball produced by the projectedlight source is cast on the indicating chart about 5 m (15 ft)away
23、at a magnification of 901103, mounted so as not totouch the test specimen when a test is in progress (see Note 3),and having a separate magnifying lens system for eachspecimen tested simultaneously.NOTE 3One magnifying lens system that has been found acceptableconsists of two lenses: a projection an
24、d a relay lens enclosed in a sealedtube. In this system, the relay lens is located nearer the test specimen andhas a focal length of 50.8 mm (2 in.) and is located approximately 115 mm(412 in.) from the indicator ball. The projection lens has a focal length of41.4 mm (158 in.), and relative aperture
25、 of f1.6 and is 133.1 mm (514 in.)from the relay lens.5.4 Indicating Charts, composed of stiff material approxi-mately 600 mm (24 in.) high by 250 mm (10 in.) wide, with awhite surface and a vertical black line 2 mm (116 in.) wide,centered and running the complete length of the chart, and ahorizonta
26、l black line 1 mm (132 in.) in width midway on thechart, identified as the zero (0) or starting line, and 2-mm(116-in.) horizontal graduations above and below the zero lineon the entire length of the vertical line, and a means forattaching this chart vertically and firmly to a distant wall.5.5 Molds
27、, rigid, watertight molds with a smooth interiorsurface made of steel, cast iron, or other nonabsorbent materialnonreactive with the cementitious mixture being tested, cylin-drical in shape, with internal height twice the internal diameter.Three sizes of molds are used in this test method with heigh
28、tsof 100, 150, 300 mm (4, 6, 12 in.).5.6 Rods, two straight, steel tamping rods: one 10 mm (38in.) in diameter and approximately 300 mm (12 in.) in lengthand the other 16 mm (58 in.) in diameter and approximately600 mm (24 in.) in length. The 10-mm rod shall be used withpaste, grout, and mortar. The
29、 16-mm rod shall be used withconcrete.6. Test Specimen6.1 Unless otherwise specified, prepare two test specimensfrom each batch to be tested simultaneously using duplicatetest apparatus. For cement pastes, grouts, and mortars where allthe aggregate will pass through a 4.75-mm (No. 4) sieve, usethe 1
30、00-mm (4-in.) mold. For cementitious mixtures containing3An 11-mm (716-in.) nylon plastic indicator ball has been found acceptable formost tests and is available from U.S. Plastics Corp., 1390 Neubrecht Rd., Lima, OH45801.FIG. 1 Apparatus for Early Change in HeightC 827 01a (2005)2aggregate that wil
31、l not all pass through a 4.75-mm sieve, butwhich will all pass the 12.5-mm (12-in.) sieve, use the 150-mm(6-in.) mold. For concrete mixtures having particles retained onthe 12.5-mm (12-in.) sieve or larger, use the 300-mm (12-in.)mold.7. Calibration7.1 GeneralMinimize any sources of light not requir
32、edfor the tests. Locate the test equipment and specimens on asurface substantially free of vibration during the test. If desired,use a single projected light source for both test specimens withduplicate magnifying lens systems and indicating charts.7.2 Apparatus CalibrationCalibrate the entire appar
33、atusprior to the start of each test. Darken the room, illuminate theprojected light source, and place the dummy test specimens(preferably hardened test specimens) in the light beam beforeeach of the magnifying lens systems. Adjust the location ofeach test specimen until a sharp, clear image of the i
34、ndicatorball is produced on the indicating chart. Then reposition theindicating chart so that the indicating ball image falls on thezero line. Place a steel rod of known diameter (see Note 4)horizontally on top of each indicator ball and record the heightof the image it produces on its respective in
35、dicating chart. Theratio of the image height to the actual rod diameter is themagnification of the lens system. Moving the projected lightsource, test specimen, and magnifying lens system toward oraway from the indicating chart can change the magnification.Once proper magnification (90 to 1103) is o
36、btained, removethe dummy test specimens and do not change the relativelocations of the test apparatus during the test.NOTE 4The shank of a 2-mm (116-in.) twist drill bit has been foundsatisfactory for most tests.8. Preparation of Mixtures8.1 GeneralBring all materials to a temperature of 23 62.0 C (
37、73 6 3 F) before mixing. Other material temperaturesshall be used for this test method when specified. Proportion allmaterials by mass in accordance with the specifications for thecementitious mixtures to be tested.8.2 Mortars, Pastes, and Grouts:8.2.1 Either hand mix or use a suitable mechanical mi
38、xer(see Note 5) for a mixing time of 4 min, unless otherwiserecommended by the manufacturer. Place all the mixing waterin the mixing bowl prior to introduction of the other materialsfor the batch. For mortar materials that are not premixed, thesequence of mixing shall be in accordance with Practice
39、C 305.NOTE 5The mechanical mixer described in Practice C 305 is asuitable mixer. However, the clearances between paddle and bowlspecified in this test method are suitable only for mortars made with fineaggregates that are finer than the 850-m (No. 20) sieve. Mortars madewith aggregates containing pa
40、rticles coarser than the 850-m sieve mayrequire special clearances or a different type of paddle to permit the mixerto operate freely and to avoid damage to the paddle and bowl.8.2.2 Determine the consistency of he mixtures by the flowtest in accordance with the applicable provisions of TestMethod C
41、 1437. If this procedure is used, the flow after 5 dropsof the flow table in3sis145orless. A plastic mixture shouldhave a flow of 100 to 125, and a flowable mixture should havea flow above 125 when tested by the preceding modification ofTest Method C 109/C 109M but not less than 30 s when testedusin
42、g the flow-cone procedure of Test Method C 939. A fluidmixture should have a time of efflux of 10 to 30 s when testedby the flow-cone procedure. The water required to produce thespecified consistency shall be determined by the testing of trialbatches. Fresh materials shall be used to make each trial
43、. If notspecified or recommended otherwise, use sufficient mixingwater to produce a flow of 135 6 5. For premixed mortars orgrouts, use the amount of water suggested by the manufacturerfor the intended application. The consistency should be deter-mined and the values recorded for all tests.8.3 Concr
44、eteMix concrete either manually or in a suitablelaboratory mixer in accordance with the applicable provisionsof Practice C 192/C 192M. Determine the consistency of theconcrete by the slump test in accordance with the applicableportions of Test Method C 143/C 143M, and unless otherwisespecified, use
45、sufficient mixing water to produce a slump of 906 15 mm (312 612 in.).9. Molding Specimens9.1 Fabricate 100-mm and 150-mm (4-in. and 6-in.) speci-mens by filling the mold in a continuous pouring operation forpourable mixtures or in three layers with consolidation of eachlayer by tapping the outside
46、of the mold ten times with a10-mm (38-in.) diameter rod in the case of mixtures that are notpourable. Fabricate 300-mm (12-in.) specimens in accordancewith Practice C 192/C 192M.9.2 Screed off the surface of the test specimen to the top ofthe mold. In cases where extreme shrinkage or expansion ofmat
47、erial is anticipated, adjust the height of the test material to66mm(14 in.) with respect to the mold height.10. Procedure10.1 Place an indicator ball in the center of the surface ofeach specimen. Tap the indicator ball lightly so that approxi-mately one half of the balls diameter penetrates the test
48、specimen mixture. Remove pieces of large aggregate directlyunder the indicator balls, and repeat the procedure. Then tapthe outer side of the molds lightly three times so that theindicator balls can adjust to their own natural displacementlevel in the mixture. Position each specimen between theproje
49、cted light source and the magnifying lens system. Adjustthe position of the test specimens horizontally until the imagesof the indicator balls on the indicating charts are sharp andclear. Reposition the indicating charts so that the indicating ballimages fall on the zero lines. Complete these activities in notmore than 5 min after completion of mixing unless otherwisespecified. Record this time as the start of the test. Unlessotherwise specified, conduct tests with test specimens that arefree to evaporate to the atmosphere. Record ambient airtempe
