1、Designation: C 531 00 (Reapproved 2005)Standard 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 C 531; the number immediately following the desig
2、nation 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 (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by
3、 agencies of the Department of Defense.1. Scope1.1 This test method covers the measurement of the linearshrinkage during setting and curing and the coefficient ofthermal expansion of chemical-resistant mortars, grouts, mono-lithic surfacings, and polymer concretes.1.2 A bar of square cross-section i
4、s cast to a prescribedlength in a mold that holds measuring studs that are captured inthe ends of the finished casting.1.2.1 The change in length after curing is measured andused to calculate shrinkage.NOTE 1Shrinkage determinations should not be made on sulfurmortars, since this test method cannot
5、truly reflect the overall linearshrinkage of a sulfur mortar.1.2.2 The change in length at a specific elevated temperatureis measured and used to calculate the coefficient of thermalexpansion.1.3 This test method is limited to materials with aggregatesize of 0.25 in. (6 mm) or less.1.4 The values st
6、ated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.5 This 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
7、 safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 287 Specification for Chemical-Resistant Sulfur MortarC 490 Practice for Use of Apparatus for the Determinationof Length Change of Hardened Cement Paste,
8、Mortar, andConcreteC 904 Terminology Relating to Chemical-Resistant Non-metallic Materials3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, see Terminology C 904.4. Significance and Use4.1 This test method offers a means of comparing therelative linear shrinkage and coef
9、ficient of thermal expansion.4.1.1 The material to be tested is placed in the mold in afluid or plastic state. As the material makes a transition to asolid state, it adheres to and captures the end studs.4.1.2 The linear shrinkage measured is the change in lengththat occurs after the material is rig
10、id enough and strong enoughto move the studs.4.2 This test method can be used for research purposes toprovide information on linear changes taking place in the testmaterials. Other dimensional changes may occur that do notmanifest themselves as changes in length.5. Apparatus5.1 Weighing Equipment, s
11、hall be capable of weighingmaterials or specimens to 60.3 % accuracy.5.2 Equipment for Mixing, consisting of a container ofsuitable size preferably made of corrosion-resistant metal, or aporcelain pan, and a sturdy spatula or trowel.5.3 Specimen Mold, (see Practice C 490) permitting themolding of ba
12、rs with a metal stud embedded in each end. Thebars shall be 1 in. (25 mm) square by 10 in. (250 mm) betweenstuds when molded. A standard 10-in. (250-mm) metal barshall be provided; this is used to space the studs.5.4 StudsNickel alloy studs, which have linear coefficientof thermal expansion of 7.2 3
13、 106per F (4 3 106per C),knurled on one end and threaded on the other (for securing inend blocks), approximately 0.8 in. (20 mm) long. Remove anymachining burrs from the flat end of the stud.1This test method is under the jurisdiction of ASTM Committee C03 onChemical-Resistant Nonmetallic Materials
14、and is the direct responsibility ofSubcommittee C03.01 on Mortars and Carbon Brick.Current edition approved April 1, 2005. Published April 2005. Originallyapproved in 1963. Last previous edition approved in 2000 as C 531 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcont
15、act 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, United States.5.5 ComparatorA direct
16、-reading dial or digital microme-ter to permit readings to 0.0001 in. (0.0025 mm).5.6 Micrometers, one having a range suitable for measuringthe studs (0.8 in.), and one having a range suitable formeasuring the standard 10-in. (254-mm) bar, both readable to0.0001 in. (0.0025 mm).5.7 Constant-Temperat
17、ure OvenAn oven capable of at-taining temperatures to 210F (99C) is required. The ovenshould be capable of maintaining a set temperature constant to63F (61.5C).6. Test Specimens6.1 TemperatureThe standard temperature of the productconstituents, mold apparatus, and the temperature in thevicinity of t
18、he mixing operation shall be 73 6 4F (23 6 2C),unless otherwise specified by the manufacturer. The actualtemperature shall be recorded.6.2 Number of SpecimensA minimum of four test barspecimens shall be prepared for each material tested.6.3 Preparation of Materials:6.3.1 Mix the material in the prop
19、ortions specified by themanufacturer of the materials. If the proportions so specifiedare by volume, weigh the constituents and report the corre-sponding proportions by weight. Fresh material shall be usedand the manufacturer shall be consulted if the age of thematerial is not known.6.3.2 Mix a stan
20、dard batch size of 2400 g of material andprepare four 1-in. (25-mm) square by 10-in. (250-mm) (ap-proximate) bars.6.3.3 For sulfur mortars, prepare the samples in accordancewith the appropriate section of Specification C 287.6.4 Molding Test Specimens:6.4.1 Lubricate the mold by applying a thin film
21、 of moldrelease or lubricant like silicone stop-cock grease.6.4.2 Measure the standard bar with a micrometer to60.0001 in. (0.0025 mm).6.4.3 Measure the lengths of the studs with a micrometer to60.0001 in. (0.0025 mm).6.4.4 In assembling the mold, the end blocks must movefreely in the mold before se
22、curing to the mold with machinescrews.6.4.5 Measure the measuring studs with micrometers andcarefully 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 toeliminate air pockets by working the material with a spatula orthin
23、trowel. Level the top surface with the spatula and strike offthe excess evenly. In the case of sulfur mortars, at least threeseparate pourings shall be made.6.4.7 After casting the specimens, remove the machinescrews holding the end blocks to permit free movement of theblocks.7. Conditioning7.1 Resi
24、n and Sulfur MaterialsTest specimens shall beremoved from molds only after an initial curing time deemedsuitable by the manufacturer.7.2 Silica and Silicate MaterialsImmediately after mold-ing the specimens, cover the mold with polyethylene sheetingor other suitable material to prevent rapid evapora
25、tion ofsurface moisture and subsequent deformation of the specimenbar. Disassemble the mold (deviations in the time mortars, etc.are kept in the mold, are to be reported) as described in 7.1.8. Procedure for Linear Shrinkage8.1 Determine the length of the bar by inserting it in thelength comparator.
26、NOTE 2In cases where shrinkage in the specimens is great enoughthat comparator readings are no longer possible, insertion of a spacer(such as a metal washer) under the bottom stud holder of the comparatorwill enable readings to be made. When this is necessary, standard barreadings will also change a
27、nd proper adjustments in calculation must bemade.8.2 The frequency of shrinkage measurement depends onthe information desired; for example, if it is desired to followthe shrinkage at room temperature, or at a specific temperature,readings can be made as long as shrinkage continues.Atypicalschedule i
28、s as follows: daily for 2 weeks at 73 6 4F (23 62C), then after 3 days at 210F (99C) or 140F (60C),depending on the material (see 9.2). If the specimens are heatedto induce cure, cool overnight at 73F (23C) before measur-ing.8.2.1 Repeat heating and cooling cycles until the barsachieve a constant le
29、ngth when measured at 73F (23C).9. Procedure for Linear Coefficient of ThermalExpansion9.1 Use the specimens previously used for shrinkage deter-minations. Heat the specimens to constant length in an oven atthe elevated temperature indicated in 9.2, then condition at73F for a minimum of 16 h.9.2 Det
30、ermine the length of each bar at 73F by measuringwith the length comparator. Then place the bars in an ovenheated as 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 timeand measure (Note 3). Remove
31、 the bars at a rate that does notpermit the temperature of the oven to drop below the estab-lished temperature. In the case of silicate materials, put thespecimens into a desiccator for cooling immediately after thereading is taken at the elevated temperature.NOTE 3Usually, the length can be read wi
32、thin 4 or 5 s after removalfrom the oven.9.3.1 If the specimen does not return to its original length oncooling to 73F, shrinkage is still taking place, and theprocedure in 9.1 and 9.2 shall be repeated.10. Calculation10.1 ShrinkageCalculate the linear shrinkage for the fourspecimens as follows:Perc
33、ent shrinkage 5 L02 L!/L0# 3 100 (1)where:L0= original length (length of standard bar), in., (mm), andL = length as measured during or after cure, in. (mm),excluding studs.C 531 00 (2005)210.2 Linear Coeffcient of Thermal ExpansionCalculatethe linear coefficient of thermal expansion per F (C), C,oft
34、hefour specimens as follows:C 5 Z 2 Y 2 W!/TW 2 X! (2)where:Z = length of bar, including studs, at elevated temperature,in. (mm),Y = length of stud expansion, in. (mm), = X 3 T 3 k(where k is the linear coefficient of thermal expansionper F (C) of the studs),W = length of bar, including studs, at lo
35、wer temperature, in.(mm),T = temperature change, F (C) andX = length of the two studs at lower temperature, in. (mm).11. Report11.1 Report the following information:11.1.1 Manufacturers name of the material and generictype,11.1.2 Mixing ratio,11.1.3 Conditioning procedure,11.1.4 Test conditions, (te
36、mperature and humidity),11.1.5 Total duration of test in days, including heat cycles,and11.1.6 Individual and averaged results of linear shrinkageand coefficient of thermal expansion.12. Precision12.1 The precision of this test method has not yet beenestablished.13. Keywords13.1 brick mortars; grout
37、s; linear shrinkage; monolithicsurfacings; mortars; polymer concretes; thermal expansion; tilegroutsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that dete
38、rmination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or
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40、t your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 531 00 (2005)3
