1、Designation: C652 14Standard 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 U.S. Department of Defense.1. Scope*1.1 This specification covers hollow buildi
3、ng brick 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
4、 cross-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 4.3). Thisspecification does not cover brick intended for use as pavingbrick (see Specification C902).
5、1.2 The property requirements of this specification apply atthe time of purchase. The use of results from testing of brickextracted from masonry structures for determining confor-mance or nonconformance to the property requirements (Sec-tion 6) of this standard is beyond the scope of this specificat
6、ion.1.3 Brick covered by this specification are ceramic productsmanufactured primarily from clay, shale, or similar naturallyoccurring substances and subjected to a heat treatment atelevated temperatures (firing). The heat treatment shall developsufficient fired bond between the particulate constitu
7、ents toprovide the strength and durability requirements of this speci-fication. Additives or recycled materials are permitted to beincluded at the option of the manufacturer. (See “firing” and“firing bond” in Terminology C1232.)1.3.1 This specification and its individual requirements shallnot be use
8、d to qualify or corroborate the performance of amasonry unit made from other materials, or made with otherforming methods, or other means of binding the materials.1.4 Hollow brick differ from unglazed structural clay tile(Specifications C34 and C212) and solid brick (SpecificationsC62 and C216). Hol
9、low brick require greater shell and webthicknesses and higher 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 constru
10、cted of hollow brick from thoseconstructed of structural clay 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 specif
11、ication.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.2. Referenced Documents2.1 ASTM Standards:2C34 Specification for Structural C
12、lay Load-Bearing WallTileC62 Specification for Building Brick (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
13、 Shale)C902 Specification for Pedestrian and Light Traffic PavingBrickC1232 Terminology of Masonry3. Terminology3.1 DefinitionsFor definitions relating to masonry andhollow brick, refer to Terminology C1232.4. Classification4.1 GradesTwo grades of hollow brick are covered:1This specification is unde
14、r 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 Feb. 1, 2014. Published March 2014. Originallyapproved in 1970. Last previous edition approved in 2013 as C652 13. D
15、OI:10.1520/C0652-14.2For 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.*A Summary of Changes section appears at
16、the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.1 Grade SWHollow brick intended for use where ahigh and uniform degree of resistance to frost action anddisintegration by weathering is desired and the exposu
17、re issuch that the hollow brick may be frozen when permeated withwater.4.1.2 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 when exposed to temperatures belowfreezin
18、g.4.2 TypesFour types of hollow brick are covered:4.2.1 Type HBSHollow brick for general use in masonry.4.2.2 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.4.2.3 Type HBAHollow brick fo
19、r general use in masonryselected to produce characteristic architectural effects resultingfrom nonuniformity in size and texture of the individual units.4.2.4 Type HBBHollow brick for general use in masonrywhere a particular color, texture, finish, uniformity, or limits oncracks, warpage, or other i
20、mperfections detracting from theappearance are not a consideration.4.2.5 When the type is not specified, the requirements forType HBS shall govern.4.3 ClassTwo classes of hollow brick are covered:4.3.1 Class H40VHollow brick intended for use wherevoid areas or spaces greater than 25 %, but not great
21、er than40 %, of the gross cross-sectional area of the unit measured inany plane parallel to the surface containing the cores, cells, ordeep frogs are desired. The void spaces, the web thicknesses,and the shell thicknesses shall comply with the requirements ofSection 10 on Coring and Frogging.4.3.2 C
22、lass H60VHollow brick intended for use wherelarger void areas are desired. The sum of these void 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 sp
23、aces, the web thicknesses, and the shell thicknessesshall comply with the requirements of Section 10 on Coringand Frogging and to the minimum requirements contained inTable 1 (see Fig. 1).4.3.3 When the class is not specified, the requirements ofClass H40V shall govern.5. Materials and Manufacture5.
24、1 The body of all hollow brick shall be of clay, shale, fireclay, or mixtures of these materials, with or withoutadmixtures, burned to meet the requirements of this specifica-tion. Any coloring or other materials added to the clay shall besuitable ceramic materials and shall be well distributedthrou
25、ghout the body.5.2 Colors and textures produced by application of inor-ganic coatings to the faces of the 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
26、 the sand does notform a continuous coating, shall not be considered as surface-colored brick for the purpose 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
27、cycles of freezing thawing there is noobservable difference in the applied finish when viewed from a distance 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 lo
28、cations may be accepted in place of the freezing and thawingtest, upon consent of the purchaser.5.3 The brick 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
29、of the construction.5.4 If any post-firing coatings or surface treatments areapplied by the manufacturer, the manufacturer shall report thetype and extent of these coatings or surface treatments in allcertificates of compliance with this specification.6. Physical Properties6.1 DurabilityWhen grade i
30、s not specified, the require-ments for Grade SW shall govern.6.1.1 Physical Property RequirementsThe brick shall con-form 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 forceperpe
31、ndicular to the bed surface of the unit, with the unit in thestretcher position.6.1.2 Absorption AlternateThe saturation coefficient re-quirement does not apply, provided that the 24-h cold waterabsorption of each of the five units tested does not exceed8.0 %.6.1.3 Freezing and Thawing AlternativeTh
32、e requirementsfor 5-h boiling water absorption and saturation coefficient donot apply, provided a sample 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.N
33、OTE 2The 50-cycle freezing and thawing test is used as analternative only when the brick do not conform to either Table 2requirements for maximum water absorption and saturation coefficient, orto the requirements of the Absorption Alternate in 6.1.2.6.1.3.1 Grade SW: Breakage and Weight LossRequirem
34、entNo individual unit separates or disintegratesresulting in a weight loss greater than 0.5 % of its original dryweight.6.1.3.2 Grade SW: Cracking RequirementNo individualunit develops a crack that exceeds, in length, the units leastdimension.TABLE 1 Class H60VHollow Brick Minimum Thicknessof Face S
35、hells and Webs, in. (mm)Nominal Width of UnitsFace Shell ThicknessesEnd Shells orEnd WebsSolidCored 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
36、 1426.1.4 Low Weathering Index Alternative:6.1.4.1 If the brick are intended for use exposed to 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 app
37、ly, but the minimum average compressive strengthrequirement of 2500 psi (17.2 MPa) shall apply.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
38、 inches, asdefined as follows.3A Freezing Cycle Day is any day during which the air temperaturepasses 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
39、) or below, and the mean number of days during which the maximumtemperature was 32F (0C) or below.3Data needed to determine the weathering for any locality may be found orestimated from tables of Local Climatological DataAnnual Summary withComparative Data from the National Oceanic and Atmospheric A
40、dministration.FIG. 1 Hollow Brick UnitsTABLE 2 Physical RequirementsDesig-nationCompressive Strengthgross area, min, psi(MPa)Water Absorptionby 5-hBoiling, max, %SaturationCoefficient,maxAverage of5 brickIndividualAverageof 5 brickIndi-vidualAverageof 5 brickIndi-vidualGrade SWGrade MW3000 (20.7)250
41、0 (17.2)2500 (17.2)2200 (15.2)17.022.020.025.00.780.880.800.90C652 143Winter 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 ofthe last ki
42、lling frost in the spring. The winter rainfall for any period isequal to the total precipitation 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 li
43、sted. The index for geographical locations nearthe 50 line should be determined by analysis of 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
44、 exposure is found in Fig. 2. The specifier may use theserecommendations or use the grade descriptions and physical requirementsalong with use exposure and local climatological conditions to selectgrade.6.2 StrengthWhen hollow brick are required havingstrengths greater than prescribed in Table 2, th
45、e purchaser shallspecify the desired minimum compressive strength.6.3 Initial Rate of Absorption (IRA)Test results for IRAshall be determined in accordance with the Initial Rate ofAbsorption (Suction) (Laboratory Test) section of Test Meth-ods C67 and shall be furnished at the request of the specifi
46、er orpurchaser. IRA is not a qualifying condition or property ofunits in this specification. This property is measured in order toassist in mortar selection and material handling in the construc-tion process. See Note 4.NOTE 4Initial Rate of Absorption (Suction)Both laboratory andfield investigation
47、 have shown that strong and watertight joints betweenmortar and masonry units are not achieved by ordinary constructionmethods when the units as laid have excessive initial rates of absorption.Mortar that has stiffened somewhat because of excessive loss of mixingwater to a unit may not make complete
48、 and intimate contact with thesecond unit, resulting in poor adhesion, incomplete bond, and water-permeable joints of low strength. IRA of the units is determined by theoven-dried procedure described in the IRA (Suction) (Laboratory Test) ofTest Methods C67. IRAin the field depends on the moisture c
49、ontent of themasonry unit and is determined in accordance with the IRA (Suction)Field Test of Test Methods C67. Units having average field IRAexceeding30 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 the unit.7. Efflorescence7.1 Brick are not required to be tested for efflorescence tocomply
