1、Designation: C531 00 (Reapproved 2012)C531 18Standard Test Method forLinear Shrinkage and Coefficient of Thermal Expansion ofChemical-Resistant Mortars, Grouts, Monolithic Surfacings,and Polymer Concretes1This standard is issued under the fixed designation C531; the number immediately following the
2、designation indicates 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.This standard has been approved for us
3、e by agencies of the U.S. Department of Defense.1. Scope1.1 This test method covers the measurement of the linear shrinkage during setting and curing and the coefficient of thermalexpansion of chemical-resistant mortars, grouts, monolithic surfacings, and polymer concretes.1.2 Abar of square cross-s
4、ection is cast to a prescribed length in a mold that holds measuring studs that are captured in the endsof the finished casting.1.2.1 The change in length after curing is measured and used to calculate shrinkage.NOTE 1Shrinkage determinations should not be made on sulfur mortars, since this test met
5、hod cannot truly reflect the overall linear shrinkage of asulfur mortar.1.2.2 The change in length at a specific elevated temperature is measured and used to calculate the coefficient of thermalexpansion.1.3 This test method is limited to materials with aggregate size of 0.25 in. (6 mm) or less.1.4
6、The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, assoc
7、iated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internatio
8、nally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C287 Specifi
9、cation for Chemical-Resistant Sulfur MortarC490 Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and ConcreteC904 Terminology Relating to Chemical-Resistant Nonmetallic MaterialsE177 Practice for Use of the Terms Precision and Bias in ASTM Test M
10、ethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 DefinitionsFor definitions of terms used in this test method, see Terminology C904.4. Significance and Use4.1 This test method offers a means of comparing the relative linear shri
11、nkage and coefficient of thermal expansion.1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Aug. 1, 2012July
12、1, 2018. Published September 2012November 2018. Originally approved in 1963. Last previous edition approved in 20052012as C531 00 (2005).(2012). DOI: 10.1520/C0531-00R12.10.1520/C0531-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceas
13、tm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards 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 standard an indication of what changes have been made to the previous versi
14、on. 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 ASTM is to be considered the official document.Copyright ASTM Internationa
15、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.1 The material to be tested is placed in the mold in a fluid or plastic state.As the material makes a transition to a solid state,it adheres to and captures the end studs.4.1.2 The linear shrinkage measured is
16、 the change in length that occurs after the material is rigid enough and strong enough tomove the studs.4.2 This test method can be used for research purposes to provide information on linear changes taking place in the testmaterials. Other dimensional changes may occur that do not manifest themselv
17、es as changes in length.5. Apparatus5.1 Weighing Equipment, shall be capable of weighing materials or specimens to 60.3 % accuracy.5.2 Equipment for Mixing, consisting of a container of suitable size preferably made of corrosion-resistant metal, or a porcelainpan, and a sturdy spatula or trowel.5.3
18、Specimen Mold, (see Practice C490) permitting the molding of bars with a metal stud embedded in each end. The bars shallbe 1 in. (25 mm) square by 10 in. (250 mm) between studs when molded.Astandard 10-in. (250-mm) metal bar shall be provided;this is used to space the studs.5.4 StudsNickel alloy stu
19、ds, which have linear coefficient of thermal expansion of 7.2 106 per F (4 106 per C), knurledon one end and threaded on the other (for securing in end blocks), approximately 0.8 in. (20 mm) long. Remove any machiningburrs from the flat end of the stud.5.5 ComparatorA direct-reading dial or digital
20、micrometer to permit readings to 0.0001 in. (0.0025 mm).5.6 Micrometers, one having a range suitable for measuring the studs (0.8 in.), and one having a range suitable for measuringthe standard 10-in. (254-mm) bar, both readable to 0.0001 in. (0.0025 mm).5.7 Constant-Temperature OvenAn oven capable
21、of attaining temperatures to 210F (99C) is required. The oven should becapable of maintaining a set temperature constant to 63F (61.5C).6. Test Specimens6.1 TemperatureThe standard temperature of the product constituents, mold apparatus, and the temperature in the vicinity ofthe mixing operation sha
22、ll be 73 6 4F (23 6 2C), unless otherwise specified by the manufacturer. The actual temperature shallbe recorded.6.2 Number of SpecimensA minimum of four test bar specimens shall be prepared for each material tested.6.3 Preparation of Materials:6.3.1 Mix the material in the proportions specified by
23、the manufacturer of the materials. If the proportions so specified are byvolume, weigh the constituents and report the corresponding proportions by weight. Fresh material shall be used and themanufacturer shall be consulted if the age of the material is not known.6.3.2 Mix a standard batch size of 2
24、400 g of material and prepare four 1-in. (25-mm) square by 10-in. (250-mm) (approximate)bars.6.3.3 For sulfur mortars, prepare the samples in accordance with the appropriate section of Specification C287.6.4 Molding Test Specimens:6.4.1 Lubricate the mold by applying a thin film of mold release or l
25、ubricant like silicone stop-cock grease.6.4.2 Measure the standard bar with a micrometer to 60.0001 in. (0.0025 mm).6.4.3 Measure the lengths of the studs with a micrometer to 60.0001 in. (0.0025 mm).6.4.4 In assembling the mold, the end blocks must move freely in the mold before securing to the mol
26、d with machine screws.6.4.5 Measure the measuring studs with micrometers and carefully adjust in the end blocks by means of the standard barsupplied with the mold.6.4.6 Fill the molds with the material, taking care to eliminate air pockets by working the material with a spatula or thin trowel.Level
27、the top surface with the spatula and strike off the excess evenly. In the case of sulfur mortars, at least three separate pouringsshall be made.6.4.7 After casting the specimens, remove the machine screws holding the end blocks to permit free movement of the blocks.7. Conditioning7.1 Resin and Sulfu
28、r MaterialsTest specimens shall be removed from molds only after an initial curing time deemed suitableby the manufacturer.7.2 Silica and Silicate MaterialsImmediately after molding the specimens, cover the mold with polyethylene sheeting or othersuitable material to prevent rapid evaporation of sur
29、face moisture and subsequent deformation of the specimen bar. Disassemblethe mold (deviations in the time mortars, etc. are kept in the mold, are to be reported) as described in 7.1.C531 1828. Procedure for Linear Shrinkage8.1 Determine the length of the bar by inserting it in the length comparator.
30、NOTE 2In cases where shrinkage in the specimens is great enough that comparator readings are no longer possible, insertion of a spacer (such asa metal washer) under the bottom stud holder of the comparator will enable readings to be made. When this is necessary, standard bar readings will alsochange
31、 and proper adjustments in calculation must be made.8.2 The frequency of shrinkage measurement depends on the information desired; for example, if it is desired to follow theshrinkage at room temperature, or at a specific temperature, readings can be made as long as shrinkage continues. A typicalsch
32、edule is as follows: daily for 2 weeks at 73 6 4F (23 6 2C), then after 3 days at 210F (99C) or 140F (60C), dependingon the material (see 9.2). If the specimens are heated to induce cure, cool overnight at 73F (23C) before measuring.8.2.1 Repeat heating and cooling cycles until the bars achieve a co
33、nstant length when measured at 73F (23C).9. Procedure for Linear Coefficient of Thermal Expansion9.1 Use the specimens previously used for shrinkage determinations. Heat the specimens to constant length in an oven at theelevated temperature indicated in 9.2, then condition at 73F for a minimum of 16
34、 h.9.2 Determine the length of each bar at 73F by measuring with the length comparator. Then place the bars in an oven heatedas follows: resin, silica, and silicate materials, 210F (100C); and sulfur materials, 140F (60C).9.3 After at least 16 h, remove the bars quickly one at a time and measure (No
35、te 3). Remove the bars at a rate that does notpermit the temperature of the oven to drop below the established temperature. In the case of silicate materials, put the specimensinto a desiccator for cooling immediately after the reading is taken at the elevated temperature.NOTE 3Usually, the length c
36、an be read within 4 or 5 s after removal from the oven.9.3.1 If the specimen does not return to its original length on cooling to 73F, shrinkage is still taking place, and the procedurein 9.1 and 9.2 shall be repeated.10. Calculation10.1 ShrinkageCalculate the linear shrinkage for the four specimens
37、 as follows:Percent shrinkage5L02L!/L0#3100 (1)where:L0 = original length (length of standard bar), in., (mm), andL = length as measured during or after cure, in. (mm), excluding studs.where:L0 = original length (length of standard bar), in., (mm), andL = length as measured during or after cure, in.
38、 (mm), excluding studs.10.2 Linear Coeffcient of Thermal ExpansionCalculate the linear coefficient of thermal expansion per F (C), C, of the fourspecimens as follows:C 5Z 2Y 2W!/TW2X! (2)where:Z = length of bar, including studs, at elevated temperature, in. (mm),Y = length of stud expansion, in. (mm
39、), = X T k (where k is the linear coefficient of thermal expansion per F (C) of thestuds),W = length of bar, including studs, at lower temperature, in. (mm),T = temperature change, F (C) andX = length of the two studs at lower temperature, in. (mm).where:Z = length of bar, including studs, at elevat
40、ed temperature, in. (mm),Y = length of stud expansion, in. (mm), = X T k (where k is the linear coefficient of thermal expansion per F (C) of thestuds),W = length of bar, including studs, at lower temperature, in. (mm),T = temperature change, F (C) andX = length of the two studs at lower temperature
41、, in. (mm).11. Report11.1 Report the following information:11.1.1 ManufacturersManufacturers name of the material and generic type,C531 18311.1.2 Mixing ratio,11.1.3 Conditioning procedure,11.1.4 Test conditions, (temperature and humidity),11.1.5 Total duration of test in days, including heat cycles
42、, and11.1.6 Individual and averaged results of linear shrinkage and coefficient of thermal expansion.12. Precision and Bias312.1 The precision of this test method has not yet been established.is based on an interlaboratory study ofASTM C531, StandardTest Method for Linear Shrinkage and Coefficient o
43、f Thermal Expansion of Chemical-Resistant Mortars, Grouts, MonolithicSurfacings, and Polymer Concretes, conducted in 2017. Six facilities participated in this study. Each participant reported threereplicate test results. Every “test result” reported represents the average of four individual determin
44、ations. Except for the inclusionof just a single material type, Practice E691 was followed for the design and analysis of the data; the details are given in ASTMResearch Report RR:D01-1187.12.1.1 Repeatability (r)The difference between repetitive results obtained by the same operator in a given labo
45、ratory applyingthe same test method with the same apparatus under constant operating conditions on identical test material within short intervalsof time would in the long run, in the normal and correct operation of the test method, exceed the following values only in one casein 20.12.1.1.1 Repeatabi
46、lity can be interpreted as the maximum difference between two results, obtained under repeatabilityconditions, that is accepted as plausible due to random causes under normal and correct operation of the test method.12.1.1.2 Repeatability estimates are listed in Table 1 and Table 2.12.1.2 Reproducib
47、ility (R)The difference between two single and independent results obtained by different operators applyingthe same test method in different laboratories using different apparatus on identical test material would, in the long run, in thenormal and correct operation of the test method, exceed the fol
48、lowing values only in one case in 20.12.1.2.1 Reproducibility can be interpreted as the maximum difference between two results, obtained under reproducibilityconditions, that is accepted as plausible due to random causes under normal and correct operation of the test method.12.1.2.2 Reproducibility
49、estimates are listed in Table 1 and Table 2.12.1.3 The above terms (repeatability and reproducibility) are used as specified in Practice E177.12.1.4 Any judgment in accordance with statements 12.1.1 and 12.1.2 would normally have an approximate 95 % probabilityof being correct, however the precision statistics obtained in this ILS must not be treated as exact mathematical quantities whichare applicable to all circumstances and uses. The limited number of materials tested guarantees that there will be times w
