1、Designation: C652 10Standard Specification forHollow Brick (Hollow Masonry Units Made From Clay orShale)1This standard is issued under the fixed designation C652; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. 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 use by agencies of the Department of Defense.1. Scope*1.1 This specification covers hollow building br
3、ick andhollow facing brick made from clay, shale, fire clay, ormixtures thereof, and fired to incipient fusion. Four types ofhollow brick in each of two grades and two classes are covered.In this specification, the term hollow brick shall be understoodto mean hollow clay masonry units whose net cros
4、s-sectionalarea (solid area) in any plane parallel to the surface, containingthe cores, cells, or deep frogs, is less than 75 % of its grosscross-sectional area measured in the same plane (see 3.3). Thisspecification does not cover brick intended for use as pavingbrick (see Specification C902).1.2 T
5、he property requirements of this sspecification apply atthe time of purchase. The use of results from testing of brickextracted from masonry structures for determining conform-ance or nonconformance to the property requirements (Section5) of this standard is beyond the scope of this specification.1.
6、3 Brick covered by this specification are manufacturedfrom clay, shale, or similar naturally occurring substances andsubjected to a heat treatment at elevated temperatures (firing).The heat treatment shall develop sufficient fired bond betweenthe particulate constituents to provide the strength and
7、dura-bility requirements of this specification. (See “firing” and“firing bond” in Terminology C1232.)1.4 Hollow brick differ from unglazed structural clay tile(Specifications C34 and C212) and solid brick (SpecificationsC62 and C216). Hollow brick require greater shell and webthicknesses and higher
8、minimum compressive strength thanstructural clay tile, but permit greater void area and lesserdistance from exposed edge to core hole than solid brick.Therefore, environmental and structural performance may bedifferent in elements constructed of hollow brick from thoseconstructed of structural clay
9、tile or solid brick.1.5 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 specification.1.6 The values stated in inch-pound units are to be re
10、gardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2. Referenced Documents2.1 ASTM Standards:2C34 Specification for Structural Clay Load-Bearing WallTileC62 Specification for Building Brick
11、(Solid Masonry UnitsMade From Clay or Shale)C67 Test Methods for Sampling and Testing Brick andStructural Clay TileC212 Specification for Structural Clay Facing TileC216 Specification for Facing Brick (Solid Masonry UnitsMade from Clay or Shale)C902 Specification for Pedestrian and Light Traffic Pav
12、ingBrickC1232 Terminology of MasonryE835/E835M Guide for Modular Coordination of Clay andConcrete Masonry Units3. Classification3.1 GradesTwo grades of hollow brick are covered:3.1.1 Grade SWHollow brick intended for use where ahigh and uniform degree of resistance to frost action anddisintegration
13、by weathering is desired and the exposure issuch that the hollow brick may be frozen when permeated withwater.3.1.2 Grade MWHollow brick intended for use where amoderate and somewhat nonuniform degree of resistance tofrost action is permissible or where they are unlikely to bepermeated with water wh
14、en exposed to temperatures belowfreezing.3.2 TypesFour types of hollow brick are covered:1This specification is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.02 on Brick and Structural Clay Tile.Current edition approved
15、June 1, 2010. Published June 2010. Originallyapproved in 1970. Last previous edition approved in 2009 as C652 09. DOI:10.1520/C0652-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inf
16、ormation, 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 Conshohocken, PA 19428-2959, United States.3.2.1 Type HBSHollow brick for general use in
17、 masonry.3.2.2 Type HBXHollow brick for general use in masonrywhere a higher degree of precision and lower permissiblevariation in size than permitted for Type HBS is required.3.2.3 Type HBAHollow brick for general use in masonryselected to produce characteristic architectural effects resultingfrom
18、nonuniformity in size and texture of the individual units.3.2.4 Type HBBHollow brick for general use in masonrywhere a particular color, texture, finish, uniformity, or limits oncracks, warpage, or other imperfections detracting from theappearance are not a consideration.3.2.5 When the type is not s
19、pecified, the requirements forType HBS shall govern.3.3 ClassTwo classes of hollow brick are covered:3.3.1 Class H40VHollow brick intended for use wherevoid areas or hollow spaces greater than 25 %, but not greaterthan 40 %, of the gross cross-sectional area of the unitmeasured in any plane parallel
20、 to the surface containing thecores, cells, or deep frogs are desired. The void spaces, the webthicknesses, and the shell thicknesses shall comply with therequirements of Section 10 on Hollow Spaces.3.3.2 Class H60VHollow brick intended for use wherelarger void areas are desired. The sum of these vo
21、id areas shallbe greater than 40 %, but not greater than 60 %, of the grosscross-sectional area of the unit measured in any plane parallelto the surface containing the cores, cells or deep frogs. Thevoid spaces, the web thicknesses, and the shell thicknessesshall comply with the requirements of Sect
22、ion 10 on HollowSpaces and to the minimum requirements contained in Table 1(see Fig. 1).3.3.3 When the class is not specified, the requirements ofclass H40V shall govern.4. Materials and Finish4.1 The body of all hollow brick shall be of clay, shale, fireclay, or mixtures of these materials, with or
23、 without admix-tures, burned to meet the requirements of this specification.Any coloring or other materials added to the clay shall besuitable ceramic materials and shall be well distributedthroughout the body.4.2 Colors and textures produced by application of inor-ganic coatings to the faces of the
24、 brick shall be permitted withthe consent of the purchaser, provided that evidence is fur-nished of the durability of the coatings. Brick that are coloredby flashing or textured by sanding, where the sand does notform a continuous coating, shall not be considered as surface-colored brick for the pur
25、pose of this specification.NOTE 1When surface colored brick, other than sanded or flashed, arespecified for exterior use, the purchaser should require that data besubmitted showing that after 50 cycles of freezing thawing there is noobservable difference in the applied finish when viewed from a dist
26、ance of10 ft (3.0 m) under an illumination of not less than 50 ft-candles (538 lx)by an observer with normal vision.Service records of the performance of the particular coated brick inexterior locations may be accepted in place of the freezing and thawingtest, upon consent of the purchaser.4.3 The b
27、rick shall be free of defects, deficiencies, andsurface treatments, including coatings, that would interferewith the proper laying of the brick or significantly impair thestrength or performance of the construction.4.4 If any post-firing coatings or surface treatments areapplied by the manufacturer,
28、 the manufacturer shall report thetype and extent of these coatings or surface treatments in allcertificates of compliance with this specification.5. Physical Properties5.1 DurabilityWhen Grade is not specified, the require-ments for Grade SW shall govern.5.1.1 Physical Property RequirementsThe bric
29、k shallconform to the physical requirements for the Grade specified asprescribed in Table 2. For the compressive strength require-ments in Table 2, test the unit with the compressive forceperpendicular to the bed surface of the unit, with the unit in thestretcher position.5.1.2 Absorption AlternateT
30、he saturation coefficient re-quirement does not apply, provided the 24-h cold waterabsorption of each unit of a random sample of five brick doesnot exceed 8.0 %.5.1.3 Freezing and Thawing AlternativeThe requirementsfor 5-h boiling water absorption and saturation coefficient donot apply, provided a s
31、ample of five brick, meeting the strengthrequirements of Table 2, passes the freezing and thawing test asdescribed in the Rating Section of the Freezing and Thawingtest procedures of Test Methods C67.5.1.3.1 Grade SW: Breakage and Weight LossRequirementNo individual unit separates or disintegratesre
32、sulting in a weight loss greater than 0.5 % of its original dryweight.NOTE 2The 50-cycle freezing and thawing test is used as an alterna-tive only when the brick do not conform to either Table 2 requirements formaximum water absorption and saturation coefficient, or to the require-ments of the Absor
33、ption Alternate in 5.1.2.5.1.3.2 Grade SW: Cracking RequirementNo individualunit develops a crack that exceeds, in length, the units leastdimension.TABLE 1 Class H60VHollow Brick Minimum Thicknessof Face Shells and Webs, in. (mm)Nominal Width of UnitsFace Shell ThicknessesEnd Shells orEnd WebsSolidC
34、ored or DoubleShell3 and 4 (76 and 101)34 (19.05) .34 (19.05)6 (152) 1 (25.4) 112 (38) 1 (25.4)8 (203) 114 (32) 112 (38) 1 (25.4)10 (254) 138 (35) 158 (41) 118 (29.5)12 (306) 112 (38) 2 (50) 118 (29.5)C652 1025.1.4 Low Weathering Index Alternative:5.1.4.1 If the brick are intended for use exposed to
35、 weatherwhere the weathering index is less than 50 (see Fig. 2), andunless otherwise specified, the requirements given in Table 2for 5-h boiling water absorption and for saturation coefficientshall not apply, but the minimum average compressive strengthrequirement of 2500 psi (17.2 Mpa) shall apply.
36、NOTE 3The effect of weathering on brick is related to the weatheringindex, which for any locality is the product of the average annual numberof freezing cycle days and the average annual winter rainfall in inches, asdefined as follows.3A Freezing Cycle Day is any day during which the air temperature
37、passes either above or below 32F (0C). The average number of freezingcycle days in a year may be taken to equal the difference between themean number of days during which the minimum temperature was 32F(0C) or below, and the mean number of days during which the maximumtemperature was 32F (0C) or bel
38、ow.Winter Rainfall is the sum, in inches, of the mean monthly correctedprecipitation (rainfall) occurring during the period between and includingthe normal date of the first killing frost in the fall and the normal date of3Data needed to determine the weathering for any locality may be found orestim
39、ated from tables of Local Climatological DataAnnual Summary withComparative Data from the National Oceanic and Atmospheric Administration.FIG. 1 Hollow Brick UnitsTABLE 2 Physical RequirementsDesig-nationCompressive Strengthgross area, min, psi(MPa)Water Absorptionby 5-hBoiling, max, %SaturationCoef
40、ficient,maxAverage of5 brickIndividualAverageof 5 brickIndi-vidualAverageof 5 brickIndi-vidualGrade SWGrade MW3000 (20.7)2500 (17.2)2500 (17.2)2200 (15.2)17.022.020.025.00.780.880.800.90C652 103the last killing frost in the spring. The winter rainfall for any period isequal to the total precipitatio
41、n less one tenth of the total fall of snow, sleet,and hail. Rainfall for a portion of a month is prorated.Fig. 2 indicates general areas of the United States which correspond tothe weathering categories listed. The index for geographical locations nearthe 50 line should be determined by analysis of
42、weather bureau localclimatological summaries, with due regard to the effect of microclimaticconditions, especially altitude.The recommended correlation between grade of hollow brick, weath-ering index, and exposure is found in Fig. 2. The specifier may use theserecommendations or use the grade descr
43、iptions and physical requirementsalong with use exposure and local climatological conditions to selectgrade.5.2 StrengthWhen hollow brick are required havingstrengths greater than prescribed in Table 2, the purchaser shallspecify the desired minimum compressive strength.5.3 Initial Rate of Absorptio
44、n (IRA)Test results for IRAshall be determined in accordance with Section 9 of TestMethods C67 and shall be furnished at the request of thespecifier or purchaser. IRA is not a qualifying condition orproperty of units in this specification. This property is mea-sured in order to assist in mortar sele
45、ction and materialhandling in the construction process. See Note 4.NOTE 4Initial Rate of Absorption (Suction)Both laboratory andfield investigation have shown that strong and watertight joints betweenmortar and masonry units are not achieved by ordinary constructionmethods when the units as laid hav
46、e excessive initial rates of absorption.Mortar that has stiffened somewhat because of excessive loss of mixingwater to a unit may not make complete and intimate contact with thesecond unit, resulting in poor adhesion, incomplete bond, and water-permeable joints of low strength. IRA of the units is d
47、etermined by theoven-dried procedure described in the IRA (Suction) (Laboratory Test) ofTest Methods C67. IRAin the field depends on the moisture content of themasonry unit and is determined in accordance with the IRA (Suction)Field Test of Test Methods C67. Units having average field IRAexceeding30
48、 g/min per 30 in.2(30 g/min 194 cm2) should have their IRA reducedbelow 30 g/min per 30 in.2prior to laying. They may be wettedimmediately before they are laid, but it is preferable to wet themthoroughly 3 to 24 h prior to their use so as to allow time for moisture tobecome distributed throughout th
49、e unit.6. Efflorescence6.1 Brick are not required to be tested for efflorescence tocomply with this specification unless requested by the specifieror purchaser. When the efflorescence test is requested by thespecifier or purchaser, the brick shall be sampled at the place ofmanufacture, and tested in accordance with Test Methods C67,and a rating for efflorescence shall be “not effloresced.” If theGrade Recommendations for Face ExposuresExposureWeathering Index (Note 3)Less than 50 50 and greaterIn vertical surfaces:In contact with earth S
