1、Designation: C 90 08Standard Specification forLoadbearing Concrete Masonry Units1This standard is issued under the fixed designation C 90; 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 paren
2、theses 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 appli
4、cations.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 n
5、ot 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 de
6、sired 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
7、consulted as to theavailability of units having the desired features.2. Referenced Documents2.1 ASTM Standards:2C33 Specification for Concrete AggregatesC 140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC 150 Specification for Portland CementC 331 Specification for L
8、ightweight Aggregates for Con-crete Masonry UnitsC 426 Test Method for Linear Drying Shrinkage of Con-crete Masonry UnitsC 595 Specification for Blended Hydraulic CementsC 618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in ConcreteC 989 Specification for Ground Granula
9、ted Blast-FurnaceSlag for Use in Concrete and MortarsC 1157 Performance Specification for Hydraulic CementC 1209 Terminology of Concrete Masonry Units and Re-lated UnitsC 1232 Terminology of MasonryC 1314 Test Method for Compressive Strength of MasonryPrismsE 519 Test Method for Diagonal Tension (Sh
10、ear) in Ma-sonry AssemblagesE72 Test Methods of Conducting Strength Tests of Panelsfor Building Construction3. Terminology3.1 Terminology defined in Terminology C 1209 and Ter-minology C 1232 shall apply for this specification.4. Materials4.1 Cementitious MaterialsMaterials shall conform to thefollo
11、wing applicable specifications:4.1.1 Portland CementSpecification C 150.4.1.2 Modified Portland CementPortland cement con-forming to Specification C 150, modified as follows:(1) LimestoneIf calcium carbonate is added to thecement, the CaCO3content shall not be less than 85 %.(2) Limitation on Insolu
12、ble Residue1.5 %.(3) Limitation on Air Content of MortarVolume percent,22 % max.(4) Limitation on Loss on Ignition7 %.4.1.3 Blended Hydraulic CementsSpecification C 595.4.1.4 Hydraulic CementSpecification C 1157.4.1.5 PozzolansSpecification C 618.4.1.6 Blast Furnace Slag CementSpecification C 989.4.
13、2 AggregatesAggregates shall conform to the followingspecifications, except that grading requirements shall notnecessarily apply:4.2.1 Normal Weight AggregatesSpecification C33.1This specification is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsi
14、bility of SubcommitteeC15.03 on Concrete Masonry Units and Related Units.Current edition approved Nov. 1, 2008. Published November 2008. Originallyapproved in 1931. Last previous edition approved in 2006 as C 90 06b.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
15、 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 standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
16、ocken, PA 19428-2959, United States.4.2.2 Lightweight AggregatesSpecification C 331.4.3 Other ConstituentsAir-entraining agents, coloringpigments, integral water repellents, finely ground silica, andother constituents shall be previously established as suitable foruse in concrete masonry units and s
17、hall conform to applicableASTM standards or shall be shown by test or experience not tobe detrimental to the durability 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 th
18、e physical requirements prescribed in Table 1 andTable 2.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.5.1.1 When higher compressive strengths than thos
19、e listedin Table 2 are specified, the tested average net area compres-sive strength of three units shall equal or exceed the 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
20、 time of delivery to the purchaser, the linearshrinkage of units shall not exceed 0.065 %.NOTE 3The purchaser is the public 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
21、ofdelivery to the purchaser is FOB plant when the purchaser or thepurchasers agent transports the concrete masonry units, 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 w
22、eb thickness (tw) shallconform to the requirements prescribed in Table 1.NOTE 4Web thickness (tw) not conforming to the requirementsprescribed in Table 1 may be approved, provided equivalent structuralcapability has been established when tested in accordance with theapplicable provisions of Test Met
23、hods E72, C 1314, E 519, or otherapplicable tests and the appropriate design criteria developed is inaccordance with applicable 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
24、-sectional area measured in the same plane.5.5 End Flanges:5.5.1 For units having end flanges, the thickness of eachflange shall not be less than the minimum face shell thickness.NOTE 5Flanges beveled at the ends for mortarless head joint appli-cations that will be filled with grout are exempt from
25、this requirement.Flanges which are specially shaped for mortarless head joint applicationswhich have been shown by testing or field experience to provideequivalent performance are exempt from this requirement.6. Permissible Variations in Dimensions6.1 Standard UnitsFor standard units, no overall dim
26、en-sion (width, height, and length) shall differ by more than 618in. (3.2 mm) from the specified dimensions.6.2 Particular Feature 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
27、 differ by more than 618 in. (3.2 mm)from the specified standard dimension. Dimensions of moldedfeatures shall be within 6116 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 6Molded features include, but are
28、not limited to: ribs, scores,hex-shapes, and patterns.6.2.2 For split-faced units, all non-split overall dimensionsshall differ 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 th
29、e specifiedstandard dimension.NOTE 7On faces that are split or slumped, overall dimensions willvary. Consult with suppliers to determine achievable dimensional toler-ances for products including these features.7. Finish and Appearance7.1 All units shall be sound and free of cracks or otherdefects th
30、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
31、on.7.2 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 from a distance of not less than 20 ft (6.1 m) underdiffused lighting.7.2.1 Five percent of a shipment con
32、taining chips, not largerthan 1 in. (25.4 mm) in any dimension, or cracks not wider than0.02 in. (0.5 mm) and not longer than 25 % of the nominalheight of the unit, is permitted.TABLE 1 Minimum Thickness of Face Shells and WebsANominal Width (W) ofUnits, in. (mm)Face ShellThickness (tfs),min, in. (m
33、m)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 a minimum of 3 u
34、nits when measured asdescribed in Test Methods C 140.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 10 % limitdoes n
35、ot 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 be34 in. (19.1 m
36、m).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.C900827.3 The color and texture of units shall be specified by thepurchas
37、er. 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.7.4 A shipment shall not contain more than 5 % of units,including broken units, that do not meet the requirements of
38、6.1, 7.1, 7.2, and 7.2.1.8. Sampling and Testing8.1 The purchaser or authorized representative shall beaccorded proper 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 MethodsC 140.8.3 Total linea
39、r drying shrinkage shall be based on tests ofconcrete masonry units made with the same materials, concretemix design, manufacturing process, and curing method, con-ducted in accordance with Test Method C 426 and not morethan 24 months prior to delivery.9. Compliance9.1 If a sample fails to conform t
40、o the specified require-ments, the manufacturer shall be permitted to remove unitsfrom the shipment. A new sample shall be selected by thepurchaser from remaining units from the shipment with asimilar configuration and dimension and tested at the expenseof the manufacturer. If the second sample meet
41、s the specifiedrequirements, the remaining portion of the shipment repre-sented by the sample meets the specified requirements. If thesecond sample fails to meet the specified requirements, theremaining portion of the shipment represented by the samplefails to meet the specified requirements.NOTE 8U
42、nless 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 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 c
43、onform to the specification requirements, the cost is typically borneby the purchaser.10. Keywords10.1 absorption; concrete masonry units; equivalent webthickness; face shell; flange; lightweight; linear shrinkage;loadbearing; medium weight; normal weight; websAPPENDIXES(Nonmandatory Information)X1.
44、 WATER PENETRATION RESISTANCEX1.1 Exterior walls are often subjected to moisture pen-etration from one or more sources. For 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 deta
45、iling, construction,flashing, and drainage should be provided. Proper waterpenetration resistant treatments should be applied to the walls.While it is not within the scope of Specification C 90 to includeinformation on resistance to water penetration, such informa-tion and guidelines are available f
46、rom other organizations.X2. 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
47、changes in materials. For example,volume changes in concrete masonry units can be caused bymoisture gain and loss, thermal expansion and contraction, andcarbonation. To limit and control cracking due to these andother causes, proper design, detailing, construction, and mate-rials are necessary. Spec
48、ification C 90 provides a maximumlimitation on the total linear drying shrinkage potential of theunits, but it is not within the scope of this specification toTABLE 2 Strength, Absorption, and Density Classification RequirementsADensity Classification Oven-Dry Densityof Concrete, lb/ft3(kg/m3)Maximu
49、m 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 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)AConsult manufacturers for available densities.C90083address other design, detailing, construction, or material rec-ommendations. This ty
