1、Designation: C90 11aStandard Specification forLoadbearing Concrete Masonry Units1This standard is issued under the fixed designation C90; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in parent
2、heses indicates the year of last reapproval. A superscriptepsilon () 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 hollow and solid (see 5.3 and5.4) concrete
3、masonry units made from hydraulic cement,water, and mineral aggregates with or without the inclusion ofother materials. There are three classes of concrete masonryunits: (1) normal weight, (2) medium weight, and (3) light-weight. These units are suitable for both loadbearing andnonloadbearing applic
4、ations.1.2 Concrete masonry units covered by this specification aremade from lightweight or normal weight aggregates, or both.1.3 The text of this specification references notes andfootnotes which provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall no
5、t beconsidered as requirements of the standard.1.4 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.NOTE 1When particular features are des
6、ired such as surface texturesfor appearance or bond, finish, color, or particular properties such asdensity classification, higher compressive strength, fire resistance, thermalperformance or acoustical performance, these features should be specifiedseparately by the purchaser. Suppliers should be c
7、onsulted as to theavailability of units having the desired features.2. Referenced Documents2.1 ASTM Standards:2C33 Specification for Concrete AggregatesC140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC150 Specification for Portland CementC331 Specification for Light
8、weight Aggregates for Con-crete Masonry UnitsC426 Test Method for Linear Drying Shrinkage of ConcreteMasonry UnitsC595 Specification for Blended Hydraulic CementsC618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in ConcreteC989 Specification for Slag Cement for Use in C
9、oncreteand MortarsC1157 Performance Specification for Hydraulic CementC1232 Terminology of MasonryC1314 Test Method for Compressive Strength of MasonryPrismsE519 Test Method for Diagonal Tension (Shear) in MasonryAssemblagesE72 Test Methods of Conducting Strength Tests of Panelsfor Building Construc
10、tion3. Terminology3.1 Terminology defined in Terminology C1232 shall applyfor this specification.4. Materials4.1 Cementitious MaterialsMaterials shall conform to thefollowing applicable specifications:4.1.1 Portland CementSpecification C150.4.1.2 Modified Portland CementPortland cement con-forming t
11、o Specification C150, modified as follows:(1) LimestoneIf calcium carbonate is added to thecement, the CaCO3content shall not be less than 85 %.(2) Limitation on Insoluble Residue1.5 %.(3) Limitation on Air Content of MortarVolume percent,22 % max.(4) Limitation on Loss on Ignition7 %.4.1.3 Blended
12、Hydraulic CementsSpecification C595.4.1.4 Hydraulic CementSpecification C1157.4.1.5 PozzolansSpecification C618.4.1.6 Blast Furnace Slag CementSpecification C989.4.2 AggregatesAggregates shall conform to the followingspecifications, except that grading requirements shall notnecessarily apply:1This s
13、pecification is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.03 on Concrete Masonry Units and Related Units.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 1931. Last previous edition a
14、pproved in 2011 as C90 11. DOI:10.1520/C0090-11A.2For 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
15、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, United States.4.2.1 Normal Weight AggregatesSpecification C33.4.2.2 Lightweight AggregatesSpecification C331.4.3 Other ConstituentsAir-entraining
16、 agents, coloringpigments, integral water repellents, finely ground silica, andother constituents shall be previously established as suitable foruse in concrete masonry units and shall conform to applicableASTM standards or shall be shown by test or experience not tobe detrimental to the durability
17、of the concrete masonry unitsor any material customarily used in masonry construction.5. Physical Requirements5.1 At the time of delivery to the purchaser, units shallconform to the physical requirements prescribed in Table 1 andTable 2. All units shall be sound and free of cracks or otherdefects th
18、at interfere with the proper placement of the unit orsignificantly impair the strength or permanence of the construc-tion. Minor cracks, incidental to the usual method of manufac-ture or minor chipping resulting from customary methods ofhandling in shipment and delivery, are not grounds for rejec-ti
19、on.NOTE 2Higher compressive strengths than those listed in Table 2 maybe specified where required by design. Consult with suppliers to determineavailability of units of higher compressive strength.NOTE 3Oven-dry densities of concrete masonry units generally fallwithin the range of 85 to 145 lbf/ft3(
20、1360 to 2320 kg/m3). Becauseavailable densities will vary, suppliers should be consulted before speci-fying project requirements.5.1.1 When higher compressive strengths than those listedin Table 2 are specified, the tested average net area compres-sive strength of three units shall equal or exceed t
21、he specifiedcompressive strength, and the tested individual unit net areacompressive strength of all three units shall exceed 90 % of thespecified compressive strength.5.2 At the time of delivery to the purchaser, the linearshrinkage of units shall not exceed 0.065 %.NOTE 4The purchaser is the publi
22、c body or authority, association,corporation, partnership, or individual entering into a contract or agree-ment to purchase or install, or both, concrete masonry units. The time ofdelivery to the purchaser is FOB plant when the purchaser or thepurchasers agent transports the concrete masonry units,
23、or at the timeunloaded at the worksite if the manufacturer or the manufacturers agenttransports the concrete masonry units.5.3 Hollow Units:5.3.1 Face shell thickness (tfs) and web thickness (tw) shallconform to the requirements prescribed in Table 1.NOTE 5Web thickness (tw) not conforming to the re
24、quirementsprescribed in Table 1 may be approved, provided equivalent structuralcapability has been established when tested in accordance with theapplicable provisions of Test Methods E72, C1314, E519, or otherapplicable tests and the appropriate design criteria developed is inaccordance with applica
25、ble building codes.5.4 Solid Units:5.4.1 The net cross-sectional area of solid units in everyplane parallel to the bearing surface shall be not less than 75 %of the gross cross-sectional area measured in the same plane.5.5 End Flanges:5.5.1 For units having end flanges, the thickness of eachflange s
26、hall not be less than the minimum face shell thickness.NOTE 6Flanges beveled at the ends for mortarless head joint appli-cations that will be filled with grout are exempt from this requirement.Flanges which are specially shaped for mortarless head joint applicationswhich have been shown by testing o
27、r field experience to provideequivalent performance are exempt from this requirement.6. Permissible Variations in Dimensions6.1 Standard UnitsFor standard units, no overall dimen-sion (width, height, and length) shall differ by more than 618in. (3.2 mm) from the specified dimensions.6.2 Particular F
28、eature UnitsFor particular feature units,dimensions shall be in accordance with the following:6.2.1 For molded face units, no overall dimension (width,height, and length) shall differ by more than 618 in. (3.2 mm)from the specified standard dimension. Dimensions of moldedfeatures shall be within 611
29、6 in. (1.6 mm) of the specifiedstandard dimensions and shall be within 6116 in. (1.6 mm) ofthe specified placement of the molded feature.NOTE 7Molded features include, but are not limited to: ribs, scores,hex-shapes, and patterns.6.2.2 For split-faced units, all non-split overall dimensionsshall dif
30、fer by not more than 618 in. (3.2 mm) from thespecified standard dimensions.6.2.3 For slump units, no overall height dimension shalldiffer by more than 618 in. (3.2 mm) from the specifiedstandard dimension.NOTE 8On faces that are split or slumped, overall dimensions willvary. Consult with suppliers
31、to determine achievable dimensional toler-ances for products including these features.7. Finish and Appearance7.1 Where units are to be used in exposed wall construction,the face or faces that are to be exposed shall not show chips orcracks, not otherwise permitted, or other imperfections whenviewed
32、 from a distance of not less than 20 ft (6.1 m) underdiffused lighting.7.1.1 Five percent of a shipment containing chips, not largerthan 1 in. (25.4 mm) in any dimension, or cracks not wider thanTABLE 1 Minimum Thickness of Face Shells and WebsANominal Width (W) ofUnits, in. (mm)Face ShellThickness
33、(tfs),min, in. (mm)B,CWeb Thickness (tw)WebsB,D,Cmin, in.(mm)Equivalent WebThickness, min,in./linear ftE(mm/linear m)3 (76.2) and 4 (102)34 (19)34 (19) 158 (136)6 (152) 1 (25) 1 (25) 214 (188)8 (203) 114 (32) 1 (25) 214 (188)10 (254) and greater 114 (32) 118 (29) 212 (209)AAverage of measurements on
34、 a minimum of 3 units when measured asdescribed in Test Methods C140.BWhen this standard is used for units having split surfaces, a maximum of 10 %of the split surface is permitted to have thickness less than those shown, but notless than34 in. (19.1 mm). When the units are to be solid grouted, the
35、10 % limitdoes not apply and Footnote C establishes a thickness requirement for the entirefaceshell.CWhen the units are to be solid grouted, minimum face shell and web thicknessshall be not less than58 in. (16 mm).DThe minimum web thickness for units with webs closer than 1 in. (25.4 mm)apart shall
36、be34 in. (19.1 mm).EEquivalent web thickness does not apply to the portion of the unit to be filledwith grout. The length of that portion shall be deducted from the overall length ofthe unit for the calculation of the equivalent web thickness.C90 11a20.02 in. (0.5 mm) and not longer than 25 % of the
37、 nominalheight of the unit, is permitted.7.2 The color and texture of units shall be specified by thepurchaser. The finished surfaces that will be exposed in placeshall conform to an approved sample, consisting of not lessthan four units, representing the range of texture and colorpermitted.NOTE 9Co
38、ncrete masonry units are produced using a wide variety ofnatural aggregates and other materials. As such, slight variations inherentfrom natural materials should be expected. Since specifying units andapproving samples can take place several months prior to production ofactual units for a project, s
39、light variations in appearance from theapproved sample are to be expected.7.3 A shipment shall not contain more than 5 % of units,including broken units, that do not meet the requirements of6.1, 7.1, and 7.1.1.8. Sampling and Testing8.1 The purchaser or authorized representative shall beaccorded pro
40、per facilities to inspect and sample the units at theplace of manufacture from the lots ready for delivery.8.2 Sample and test units in accordance with Test MethodsC140.8.3 Total linear drying shrinkage shall be based on tests ofconcrete masonry units made with the same materials, concretemix design
41、, manufacturing process, and curing method, con-ducted in accordance with Test Method C426 and not morethan 24 months prior to delivery.9. Compliance9.1 If a sample fails to conform to the specified require-ments, the manufacturer shall be permitted to remove unitsfrom the shipment. A new sample sha
42、ll be selected by thepurchaser from remaining units from the shipment with asimilar configuration and dimension and tested. If the secondsample meets the specified requirements, the remaining portionof the shipment represented by the sample meets the specifiedrequirements. If the second sample fails
43、 to meet the specifiedrequirements, the remaining portion of the shipment repre-sented by the sample fails to meet the specified requirements.NOTE 10Unless otherwise specified in the purchase order, the cost oftests is typically borne as follows: (1) if the results of the tests show thatthe units do
44、 not conform to the requirements of this specification, the costis typically borne by the seller; (2) if the results of the tests show that theunits conform to the specification requirements, the cost is typically borneby the purchaser.10. Keywords10.1 absorption; compressive strength; concrete maso
45、nryunits; equivalent web thickness; face shell; flange; lightweight;linear drying shrinkage; loadbearing; medium weight; normalweight; websAPPENDIXES(Nonmandatory Information)X1. WATER PENETRATION RESISTANCEX1.1 Exterior walls are often subjected to moisture pen-etration from one or more sources. Fo
46、r example, basementwalls may be exposed to water from saturated soil. Above-grade exterior walls are usually exposed to wind-driven rain.To prevent water penetration, proper detailing, construction,flashing, and drainage should be provided. Proper waterpenetration resistant treatments should be appl
47、ied to the walls.While it is not within the scope of Specification C90 to includeinformation on resistance to water penetration, such informa-tion and guidelines are available from other organizations.TABLE 2 Strength, Absorption, and Density Classification RequirementsDensity Classification Oven-Dr
48、y Densityof Concrete, lb/ft3(kg/m3)Maximum WaterAbsorption, lb/ft3(kg/m3)Minimum Net AreaCompressive Strength, lb/in2(MPa)Average of 3 Units Average of 3 Units Individual Units Average of 3 Units Individual UnitsLightweight Less than 105 (1680) 18 (288) 20 (320) 1900 (13.1) 1700 (11.7)Medium Weight
49、105 to less than 125 (16802000) 15 (240) 17 (272) 1900 (13.1) 1700 (11.7)Normal Weight 125 (2000) or more 13 (208) 15 (240) 1900 (13.1) 1700 (11.7)C90 11a3X2. CRACK CONTROLX2.1 Restrained or differential movement in buildingelements and building materials can result in cracking. Somecommon causes of movement are: loads created by wind, soilpressure, seismic forces, or other external sources; settlementof foundations; or volume changes in materials. For example,volume changes in concrete masonry units can be caused bymoisture gain and
