1、Designation: C270 12Standard Specification forMortar for Unit Masonry1This standard is issued under the fixed designation C270; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indi
2、cates the year of last reapproval. Asuperscript 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. Scope*1.1 This specification covers mortars for use in the construc-tion of non-reinforce
3、d and reinforced unit masonry structures.Four types of mortar are covered in each of two alternativespecifications: (1) proportion specifications and (2) propertyspecifications.NOTE 1When the property specification is used to qualify masonrymortars, the testing agency performing the test methods sho
4、uld beevaluated in accordance with Practice C1093.1.2 The proportion or property specifications shall govern asspecified.1.3 When neither proportion or property specifications arespecified, the proportion specifications shall govern, unlessdata are presented to and accepted by the specifier to show
5、thatmortar meets the requirements of the property specifications.1.4 The text of this specification references notes andfootnotes which provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of the standard.1.5 The terms
6、used in this specification are identified inTerminologies C1180 and C1232.1.6 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.7 The fol
7、lowing safety hazards caveat pertains only to thetest methods section of this specification: This standard doesnot purport to address all of the safety concerns, if any,associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practicesa
8、nd determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:2C5 Specification for Quicklime for Structural PurposesC91 Specification for Masonry CementC109/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm C
9、ubeSpecimens)C110 Test Methods for Physical Testing of Quicklime,Hydrated Lime, and LimestoneC128 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Fine AggregateC144 Specification for Aggregate for Masonry MortarC150 Specification for Portland CementC188 Test Method for
10、 Density of Hydraulic CementC207 Specification for Hydrated Lime for Masonry Pur-posesC305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraul
11、ic Cements and ConcretesC595 Specification for Blended Hydraulic CementsC780 Test Method for Preconstruction and ConstructionEvaluation of Mortars for Plain and Reinforced UnitMasonryC952 Test Method for Bond Strength of Mortar to MasonryUnitsC979 Specification for Pigments for Integrally ColoredCon
12、creteC1072 Test Methods for Measurement of Masonry FlexuralBond StrengthC1093 Practice for Accreditation of Testing Agencies forMasonryC1157 Performance Specification for Hydraulic CementC1180 Terminology of Mortar and Grout for Unit Masonry1This specification is under the jurisdiction of ASTM Commi
13、ttee C12 onMortars and Grouts for Unit Masonry and is the direct responsibility of Subcom-mittee C12.03 on Specifications for Mortars.Current edition approved Jan. 1, 2012. Published January 2012. Originallyapproved in 1951. Last previous edition approved in 2010 as C270 10. DOI:10.1520/C0270-12.2Fo
14、r referenced ASTM standards, visit the ASTM 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.1*A Summary of Changes section appears at the end of this standa
15、rd.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.C1232 Terminology of MasonryC1324 Test Method for Examination and Analysis of Hard-ened Masonry MortarC1329 Specification for Mortar CementC1357 Test Methods for Evaluating Masonry Bo
16、ndStrengthC1384 Specification for Admixtures for Masonry MortarsC1489 Specification for Lime Putty for Structural PurposesC1506 Test Method for Water Retention of HydraulicCement-Based Mortars and PlastersC1586 Guide for Quality Assurance of MortarsE72 Test Methods of Conducting Strength Tests of Pa
17、nelsfor Building ConstructionE514 Test Method for Water Penetration and LeakageThrough MasonryE518 Test Methods for Flexural Bond Strength of Masonry2.2 Masonry Industry Council:3Hot and Cold Weather Masonry Construction Manual, Janu-ary 19993. Specification Limitations3.1 Specification C270 is not
18、a specification to determinemortar strengths through field testing.3.2 Laboratory testing of mortar to ensure compliance withthe property specification requirements of this specificationshall be performed in accordance with 5.3. The propertyspecification of this standard applies to mortar mixed to a
19、specific flow in the laboratory.3.3 The compressive strength values resulting from fieldtested mortars do not represent the compressive strength ofmortar as tested in the laboratory nor that of the mortar in thewall. Physical properties of field sampled mortar shall not beused to determine complianc
20、e to this specification and are notintended as criteria to determine the acceptance or rejection ofthe mortar (see Section 8).4. Materials4.1 Materials used as ingredients in the mortar shall con-form to the requirements specified in 4.1.1 to 4.1.4.4.1.1 Cementitious MaterialsCementitious materials
21、shallconform to the following ASTM specifications:4.1.1.1 Portland CementTypes I, IA, II, IIA, III, IIIA, orV of Specification C150.4.1.1.2 Blended Hydraulic CementsTypes IS(70),IS(70)-A, IP, IP-A of Specification C595.4.1.1.3 Hydraulic CementsTypes GU, HE, MS, and HS ofSpecification C1157 (Types MH
22、 and LH are limited to use inthe property specifications only).4.1.1.4 Portland Blast-Furnace Slag Cement (for Use inProperty Specifications Only)Types IS($70) or IS($70)-Aof Specification C595.4.1.1.5 Masonry CementSee Specification C91.4.1.1.6 Mortar CementSee Specification C1329.4.1.1.7 Quicklime
23、See Specification C5.4.1.1.8 Hydrated LimeSpecification C207, Types S orSA. Types N or NA limes are permitted if shown by test orperformance record to be not detrimental to the soundness ofthe mortar.4.1.1.9 Lime PuttySee Specification C1489.4.1.2 AggregatesSee Specification C144.4.1.3 WaterWater sh
24、all be clean and free of amounts ofoils, acids, alkalies, salts, organic materials, or other substancesthat are deleterious to mortar or any metal in the wall.4.1.4 AdmixturesAdmixtures shall not be added to mortarunless specified. Admixtures shall not add more than 65 ppm(0.0065 %) water soluble ch
25、loride or 90 ppm (0.0090 %) acidsoluble chloride to the mortars overall chloride content, unlessexplicitly provided for in the contract documents.4.1.4.1 Classified AdmixturesAdmixtures which are clas-sified as bond enhancers, workability enhancers, set accelera-tors, set retarders, and water repell
26、ents shall be in accordancewith Specification C1384.4.1.4.2 Color PigmentsColoring pigments shall be inaccordance with Specification C979.4.1.4.3 Unclassified AdmixturesMortars containing ad-mixtures outside the scopes of Specifications C1384 and C979shall be in accordance with the property requirem
27、ents of thisspecification and the admixture shall be shown to be non-deleterious to the mortar, embedded metals, and the masonryunits.4.1.4.4 Calcium ChlorideWhen explicitly provided for inthe contract documents, calcium chloride is permitted to beused as an accelerator in amounts not to exceed 2 %
28、by weightof the portland cement content or 1 % of the masonry cementcontent, or both, of the mortar.NOTE 2If calcium chloride is allowed, it should be used with cautionas it may have a detrimental effect on metals and on some wall finishes.5. Requirements5.1 Unless otherwise stated, a cement/lime mo
29、rtar, a mortarcement mortar, or a masonry cement mortar is permitted. Amortar type of known higher strength shall not be indiscrimi-nately substituted where a mortar type of anticipated lowerstrength is specified.5.2 Proportion SpecificationsMortar conforming to theproportion specifications shall co
30、nsist of a mixture of cemen-titious material, aggregate, and water, all conforming to therequirements of Section 4 and the proportion specificationsrequirements of Table 1. See Appendix X1 or Appendix X3 fora guide for selecting masonry mortars.5.3 Property SpecificationsMortar conformance to thepro
31、perty specifications shall be established by tests of labora-tory prepared mortar in accordance with Section 6 and 7.2. Thelaboratory prepared mortar shall consist of a mixture ofcementitious material, aggregate, and water, all conforming tothe requirements of Section 4 and the properties of thelabo
32、ratory prepared mortar shall conform to the requirementsof Table 2. See Appendix X1 for a guide for selecting masonrymortars.5.3.1 No change shall be made in the laboratory establishedproportions for mortar accepted under the property specifica-tions, except for the quantity of mixing water. Materia
33、ls with3Available from the Mason Contractors Association of America, 1910 SouthHighland Avenue, Suite 101, Lombard, IL 60148.C270 122different physical characteristics shall not be utilized in themortar used in the work unless compliance with the require-ments of the property specifications is reest
34、ablished.NOTE 3The physical properties of plastic and hardened mortarcomplying with the proportion specification (5.1) may differ from thephysical properties of mortar of the same type complying with theproperty specification (5.3). For example, laboratory prepared mortarsbatched to the proportions
35、listed in Table 1 will, in many cases,considerably exceed the compressive strength requirements of Table 2.NOTE 4The required properties of the mortar in Table 2 are forlaboratory prepared mortar mixed with a quantity of water to produce aflow of 110 6 5 %. This quantity of water is not sufficient t
36、o produce amortar with a workable consistency suitable for laying masonry units inthe field. Mortar for use in the field must be mixed with the maximumamount of water, consistent with workability, in order to provide sufficientwater to satisfy the initial rate of absorption (suction) of the masonry
37、units.The properties of laboratory prepared mortar at a flow of 110 6 5, asrequired by this specification, are intended to approximate the flow andproperties of field prepared mortar after it has been placed in use and thesuction of the masonry units has been satisfied. The properties of fieldprepar
38、ed mortar mixed with the greater quantity of water, prior to beingplaced in contact with the masonry units, will differ from the propertyrequirements in Table 2. Therefore, the property requirements in Table 2cannot be used as requirements for quality control of field preparedmortar. Test Method C78
39、0 may be used for this purpose.NOTE 5Air content of non-air-entrained portland cement-lime mortaris generally less than 8 %.TABLE 1 Proportion Specification RequirementsNOTETwo air-entraining materials shall not be combined in mortar.Proportions by Volume (Cementitious Materials)Mortar Type CementAM
40、ortar Cement Masonry CementHydrated Limeor Lime PuttyAggregate Ratio(Measured inDamp, Loose Con-ditions)MSNMSNCement-Lime M 1 . . . . . . . . . . . . . . . . . .14S 1 . . . . . . . . . . . . . . . . . . over14 to12N 1 . . . . . . . . . . . . . . . . . . over12 to 114O 1 . . . . . . . . . . . . . . .
41、 . . . over 114 to212Mortar Cement M 1 . . . . . . 1 . . . . . . . . . . . . Not less than 214and not more than3 times the sum ofthe separate vol-umes of cementi-tious materialsM . 1 . . . . . .S12 . . 1 . . . .S . . 1 . . . . .N . . . 1 . . . .O . . . 1 . . . .Masonry Cement M 1 . . . . . . . . . .
42、 . . . . . 1 . . .M . . . . 1 . . .S12 . . . . . 1 .S . . . . . 1 . .N . . . . . . 1 .O . . . . . . 1 .AIncludes Specification C150, C595, and C1157 cements as described in 4.1.1.TABLE 2 Property Specification RequirementsAMortar Type Average CompressiveStrength at 28 days, min,psi (MPa)Water Retent
43、ion, min, % Air Content, max, %BAggregate Ratio (Measuredin Damp, LooseConditions)Cement-Lime M 2500 (17.2) 75 12S 1800 (12.4) 75 12N 750 (5.2) 75 14CO 350 (2.4) 75 14CMortar Cement M 2500 (17.2) 75 12 Not less than 214 and notmore than 312 the sum ofthe separate volumes ofcementitious materialsS 18
44、00 (12.4) 75 12N 750 (5.2) 75 14CO 350 (2.4) 75 14CMasonry Cement M 2500 (17.2) 75 18S 1800 (12.4) 75 18N 750 (5.2) 75 20DO 350 (2.4) 75 20DALaboratory prepared mortar only (see Note 4).BSee Note 5.CWhen structural reinforcement is incorporated in cement-lime or mortar cement mortar, the maximum air
45、 content shall be 12 %.DWhen structural reinforcement is incorporated in masonry cement mortar, the maximum air content shall be 18 %.C270 1236. Test Methods6.1 Proportions of Materials for Test SpecimensLaboratory mixed mortar used for determining conformance tothis property specification shall con
46、tain construction materialsin proportions indicated in project specifications. Measurematerials by weight for laboratory mixed batches. Convertproportions, by volume, to proportions, by weight, using abatch factor calculated as follows:Batch factor 5 1440/80 times total sand volume proportion! (1)De
47、termine weight of material as follows:Mat. Weight 5 Mat.Volume Proportion 3 Bulk Density 3 Batch Factor(2)NOTE 6See Appendix X4 for examples of material proportioning.6.1.1 When converting volume proportions to batchweights, use the following material bulk densities:Material Bulk DensityPortland Cem
48、ent Obtain from bag or supplierBlended Cement Obtain from bag or supplierHydraulic Cement Obtain from bag or supplierSlag Cement Obtain from bag or supplierMasonry Cement Obtain from bag or supplierMortar Cement Obtain from bag or supplierLime Putty 80 pcf (1280 kg/m3)Hydrated Lime 40 pcf (640 kg/m3
49、)Sand 80 pcf (1280 kg/m3)NOTE 7All quicklime should be slaked in accordance with themanufacturers directions. All quicklime putty, except pulverized quick-lime putty, should be sieved through a No. 20 (850 m) sieve and allowedto cool until it has reached a temperature of 80F (26.7C). Quicklimeputty should weigh at least 80 pcf (1280 kg/m3). Putty that weighs lessthan this may be used in the proportion specifications, if the requiredquantity of extra putty is added to meet the minimum weight requirement.NOTE 8The sand is oven-dried
