1、Designation:C15609a Designation:C15611 Standard Test Method for Water Loss from a Mortar Specimen Through Liquid Membrane-Forming Curing Compounds for Concrete 1 This standard is issued under the xed designation C156; the number immediately following the designation indicates the year of original ad
2、option or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A superscript epsilon () 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
3、. Scope* 1.1 This test method covers laboratory determination of the efficiency of liquid membrane-forming compounds for curing concrete, as measured by their ability to reduce moisture loss from mortar specimens during the early hardening period. 1.2 The values stated in SI units are to be regarded
4、 as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered 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 o
5、f the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.(WarningFresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.) 2 2. Referenced
6、Documents 2.1 ASTM Standards: 3 C87 Test Method for Effect of Organic Impurities in Fine Aggregate on Strength of Mortar C150 Specication for Portland Cement C230/C230M Specication for Flow Table for Use in Tests of Hydraulic Cement C305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and
7、Mortars of Plastic Consistency C778 Specication for Sand D1475 Test Method For Density of Liquid Coatings, Inks, and Related Products D1653 Test Methods for Water Vapor Transmission of Organic Coating Films D2369 Test Method for Volatile Content of Coatings E178 Practice for Dealing With Outlying Ob
8、servations 3. Signicance and Use 3.1 The moisture retaining ability of a product as determined by this test method is used to assess the suitability of materials for contributing to an appropriate curing environment for concrete. The laboratory test method is used both in formulating and in specifyi
9、ng or qualifying curing products. This test method gives the user a measure of the ability of tested curing materials to impedetheescapeofmoisturefromahydrauliccementmortar.Sinceitisdesirabletoretainmoistureinfreshconcretetopromote the hydration process, failure of the product to minimize the escape
10、 of moisture may lead to loss of strength, cracking, shrinkage, or low abrasion resistance of the hardened concrete, or a combination thereof. 3.2 Many factors affect the laboratory test results. Test results obtained may be highly variable as indicated by the precision statement.Criticalfactorsincl
11、udetheprecisionofthecontrolofthetemperature,humidityandaircirculationinthecuringcabinet, preparation and sealing of the mortar specimens, the age and surface condition of the mortar specimen when the curing product is applied, and the uniformity and quantity of application of the curing membrane. 4.
12、 Apparatus 4.1 Mechanical Mortar Mixer, as described in Practice C305, or a larger size mixture operating on the same principle. 1 This test method is under the jurisdiction ofASTM Committee C09 on Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee C09.22 on Materials A
13、pplied to New Concrete Surfaces. Current edition approved Dec. 15, 2009.June 1, 2011. Published January 2010.June 2011. Originally approved in 1940. Last previous edition approved in 2009 as C15609.C15609a. DOI: 10.1520/C0156-09a.10.1520/C0156-11. 2 Section on Safety Precautions, Manual of Aggregate
14、 and Concrete Testing, Annual Book of ASTM Standards, Vol 04.02. 3 ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatserviceastm.org.ForAnnualBookofASTMStandards volume information, refer to the standards Document Summary page on the ASTM website. 1 This docum
15、ent is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as ap
16、propriate. In all cases only the current version of the standard as published by ASTM is to be considered the official document. *A Summary of Changes section appears at the end of this standard. Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unit
17、ed States.4.2 Flow Table, as described in Specication C230/C230M. 4.3 Molds shall be made of metal, glass, hard rubber, or plastic, and shall be watertight and rigidly constructed to prevent distortion during molding of the specimens or handling of the mold containing fresh mortar. They shall have a
18、 minimum surface area of 12000 mm 2 (18.6 in. 2 ), and a minimum depth of 19 mm ( 3 4 in.). The top surface shall be round, square, or rectangular withlengthnotmorethantwicethewidth.Thetopofthemoldshallhavearimtoprovidearmlevelsurfacetosupportthewood oatandtofacilitatethegroovingandsealingstepsofthe
19、procedure.Therimshallbeparallelwiththebottomsurfaceofthemold. NOTE 1Takecaretoavoiduseofanexcessiveamountofoil,grease,ormoldreleasecompoundonmolds,particularlyalongthetoprimwheresealing compoundwillbeapplied.Useofmaskingtapeonthetoprimduringapplicationofreleasecompoundtopreventcontaminationhasbeenfo
20、undexpedient. 4.4 SpoonA stainless steel serving spoon having a bowl 75 to 100 mm (3 to 4 in.) long and 50 to 75 mm (2 to 3 in.) wide for transferring the mortar from the mixing bowl to the mold. 4.5 Gloves, of rubber or plastic, to be worn while molding the specimens. 4.6 Tamper, of a nonabsorptive
21、, nonabrasive material such as medium-hard rubber or seasoned oak rendered non-absorptive by immersion for 15 min in paraffin at approximately 200 C.The tamper shall be rectangular with a 25 by 50-mm (1 by 2-in.) cross section and it shall be a convenient length (150 to 300 mm (6 to 12 in.). 4.7 Woo
22、d Float, approximately 75 by 280 by 20 mm thick (3 by 11 by 3 4 in.). NOTE 2A commercial wood oat equipped with a substantial handle can be readily reduced to these dimensions. The oat shall be resurfaced or replaced when there is noticeable wear to the oating surface. 4.8 Brush, medium-soft bristle
23、 50-mm (2-in.) paint brush to brush the surface of the specimens prior to sealing. 4.9 Curing Cabinet,maintainedatatemperatureof37.8 61.1C(10062F)andarelativehumidityof32 62%.Thecuring cabinetshallbeofadesignthatallowsmovementofconditionedairsuchthatthesolventfromthecuringcompoundwillbereadily evapo
24、rated and eliminated from the system. Air ow over the specimens shall be adjusted to provide an evaporation rate of 2.0 to 3.4 g/h as measured by the procedure of Annex A1. The evaporation rate shall initially be measured for each position in the cabinetinwhichaspecimenwillbeplaced,andshallbeverieda
25、nnuallyandwheneveranychangesaremadetothecabinet.The range of evaporation rates for all specimen positions in the test cabinet shall be reported. 4.10 Balance, having the capacity to determine the mass of a lled specimen mold to the nearest 0.1 g or less. 4.11 ApplicatorFor spray application, any app
26、aratus that can be used to apply the curing compound uniformly and with minimum overspray is acceptable. For brush or roller application, use the equipment recommended by the curing compound manufacturer. 5. Materials 5.1 Portland Cement, conforming to the requirements for Type I of Specication C150
27、. 5.2 Graded Standard Sand, conforming to the requirements of Specication C778. 5.3 SealingCompound,thatwillnotbeaffectedbythecuringmaterialandwhicheffectivelysealsagainstmoisturelossbetween the boundary of the specimen and the edge of the mold. NOTE 3Tissue embedding wax, readily available from sci
28、entic supply houses, is a convenient and reliable sealant. 6. Conditioning 6.1 The temperature of the room and of all materials when used in this test shall be 23 62C(736 4 F) unless otherwise specied, and the room humidity shall be 50 6 10%. 7. Number of Specimens 7.1 A set of three or more test sp
29、ecimens shall be made in order to constitute a test of a given curing material. NOTE 4Whenmorethanonesetofspecimensistobeprepared,eachsetshouldbehandledasagroupthroughoutthepreparationtomaketheelapsed time between molding and application of the curing product as uniform as possible. This may require
30、 mixing the mortar for each set separately. 7.2 For determining the quantity of curing compound to be applied (MA) calculate the total top surface area of the specimen, including the seal and the rim of the mold in square millimetres using appropriate geometric formulae. NOTE 5The area (A) used in c
31、alculating the mass loss per unit area (L) is calculated in 14.2 from the surface dimensions measured inside the seal of the specimen. 8. Proportioning and Mixing Mortar 8.1 ProportioningDeterminethesandcontentofthemortarbyaddingdrysandtoacementpastehavingawater-cementratio of 0.40 by weight, to pro
32、duce a ow of 35 6 5 in 10 drops of the ow table, following the procedure described in Test Method C87. Discard the mix used to determine the proportion of sand to cement. NOTE 6Thesand:cementratiorequiredvarieswiththesourceofthecement.Aratioof2.5:1issuggestedasastartingpoint.Flowmaybedetermined ona3
33、to4kgbatch of mortar which is conveniently mixed in the mixer described in Practice C305.The mixture used to establish the sand:cement ratio is discarded because it is thought that the age and mixing history of the mortar affect the nal moisture loss results and must be controlled. C15611 28.2 Mixin
34、gCombine the components of the mortar in a mortar-mixing machine to produce a homogeneous mortar not more than 6 min from the time the water and the cement are combined. NOTE 7A generally effective sequence is to add the cement to all of the water in the mixing bowl and allow it to stand for 30 s. T
35、hen, mix at low speed for 30 s and, without stopping the mixer, add the sand within 30 s and continue mixing for 1 min. Stop the mixer for 1 min. During the rst 15 s, scrape down the sides of the bowl. Finish by mixing for an additional 1 min, and promptly begin molding the specimens. 9. Preparing S
36、pecimens 9.1 Thoroughly clean the molds before each use. Use of a mold release is acceptable provided that care is taken to avoid its application to the top rim of the mold to prevent interference with sealing of the edge. 9.2 Half ll the mold and spread the mortar with the back of the spoon to crea
37、te a layer of approximately uniform thickness. Tamp over the entire surface with one stroke of the 25 by 50 mm (1 by 2 in.) face of the tamper per 1000 mm 2 of surface area roundedtothenearestinteger.Placeasecondlayerofmortar,sufficientinamounttoslightlyoverllthemoldandtampinasimilar manner. Using t
38、he 25-mm (1-in.) wide by 150 to 300-mm (6 to 12-in.) long edge of the tamper, ll the indentations made by the tamping and level the surface by pressing down rmly with a series of contacts across the entire surface. Strike off the specimen levelwiththetopofthemoldusingawoodoatwithonepassonly,inthedir
39、ectionofthelongaxisofthespecimenforrectangular molds, using a sawing motion of the oat. Keep the 75-mm (3-in.) face of the oat rmly in contact with the mortar and edges of the mold so that the oat creates a uniformly dense surface free of voids and cracks. 9.3 Immediately after molding, wipe the out
40、side surfaces of the molds clean, and place the specimens in the curing cabinet maintained at the conditions specied in 4.9. The specimens shall be level and not subject to vibration. The spacing between the individual specimens and between the specimens and the side walls of the cabinet shall be be
41、tween 50 and 175 mm (2 to 7 in.). Within these limits the spacing shall be the same for all specimens. Use dummy specimens to ll any empty spaces in the cabinet. 10. Surface Preparation and Edge Sealing 10.1 Removethespecimensfromthecabinetimmediatelyupondisappearanceofthesurfacewaterandlightlybrush
42、thesurface using just sufficient force to remove the laitance and glaze without scarifying the mortar surface. If surface water appears after brushing, return the specimen to the cabinet but immediately remove the specimen upon the disappearance of the surface water brought to the surface by the bru
43、shing operation, and brush again. The mortar shall be free of surface water but shall not be dry belowthesurface.Thepropersurfaceconditionwillbeattainedwhenbrushingdoesnotbringfreewatertothesurface,orproduce smearing, and can be determined by gently rubbing an area with the nger tip. NOTE 8The expos
44、ure time in the cabinet and the initial moisture loss that will result in the proper surface condition is characteristic of the curing cabinetusedandothertestingconditionsrelatedtothelaboratoryperformingthetest.Uniformityoftestsurfaceconditionsmaybemaintainedbysetting anexpectedexposuretimeorinitial
45、moistureloss.Whenanytestconditionischanged(sand,cement,andsoforth),anewexposuretimeorinitialmoisture loss, or both, shall be determined. 10.2 Form a V-shaped groove approximately 3 mm ( 1 8 in.) deep and not more than 3 mm ( 1 8 in.) wide between the edge of the mortar specimen and the mold. Fill th
46、e groove with the sealing compound. The sealing compound shall not extend more than 6mm( 1 4 in.) from the edge of the mold onto the surface of the specimen. NOTE 9Tocutoutthegrooveforsealing,thetipofapointedtrowel,apointedspatula,apointedtriangularcanopener,ora“hawksbillpoint”ground on the end of a
47、 spatula or knife blade have all been reported to be effective. 11. Application of Curing Materials 11.1Calculate the mass of the curing compound to be applied, 11.1 Determine the density of the curing compound, Dm, in accordance with Test Method D1475. 11.2 Calculate the mass of the curing compound
48、 to be applied, MA, to the nearest 0.1 g based on the specied application rate, the total surface area calculated per 7.2, and the density of the curing compound determined in accordance with Test Method Dpound, Dm. If no rate is specied, apply the curing compound at the rate of 5.0 m 2 /L (200 ft 2
49、 /gal). The method of application shall be in accordance with the manufacturers recommendations. 11.23 Immediately after sealing, weigh the specimen to the nearest 0.1 g (M 1 ); then uniformly apply the curing compound at the specied rate of application. Application shall be made expeditiously to only one specimen at a time. NOTE 10It is desirable to use a spray booth or a laboratory hood to control overspray and solvent fumes especially for curing compounds that are sprayed. However, the velocity of air moveme
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