1、Designation: C 946 91 (Reapproved 2001)Standard Practice forConstruction of Dry-Stacked, Surface-Bonded Walls1This standard is issued under the fixed designation C 946; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers material, workmanship, and con-struction procedures for applying surface bonded mortar toboth side
3、s of dry stacked concrete masonry units. It does notinclude grout, reinforcing, anchorage, or control joints sincetheir use is essentially the same as conventional concretemasonry construction, unless specifically mentioned in thispractice.NOTE 1Design and construction procedures for conventional co
4、ncretemasonry construction have been written by the American ConcreteInstitute, “Building Code Requirements for Concrete Masonry Structures”and the National Concrete Masonry Associations, “Specification for theDesign and Construction of Load-Bearing Concrete Masonry.”1.2 The values stated in inch-po
5、und units are to be regardedas the standard. The values given in parentheses are providedfor information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safet
6、y and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 55 Specification for Concrete Brick2C 90 Specification for Loadbearing Concrete MasonryUnits2C 129 Specification for Nonloadbearing Concrete MasonryUnits2C 145 S
7、pecification for Solid Load-Bearing Concrete Ma-sonry Units3C 270 Specification for Mortar for Unit Masonry2C 887 Specification for Packaged, Dry, Combined Materialsfor Surface Bonding Mortar22.2 American Concrete Institute Standard:531 Building Code Requirements for Concrete MasonryStructures, Comm
8、entary-ACI 531R-7942.3 International Masonry Industry All-Weather CouncilStandards:Recommended Practices and Guide Specifications for ColdWeather Masonry Construction52.4 National Concrete Masonry Association Standard:Specification for the Design and Construction of Load-Bearing Concrete Masonry63.
9、Storage3.1 Deliver and store surface bonding mortar in originalcontainers off the ground to prevent contact with water. Protectfrom rain with suitable covering.3.2 Store concrete masonry units off the ground to preventcontamination by mud, dust, and materials likely to causestaining or other defects
10、, and protect from rain.4. Materials and Manufacture4.1 Concrete masonry units shall be clean and dry, meetingthe requirements of Type I, moisture-controlled units, of theapplicable ASTM specification (Specifications C 55, C 90,C 129, and C 145). The surface to receive surface bondingmortar shall be
11、 free of paint, oil, efflorescence, or foreignmaterials that interfere with bonding.4.2 Mortar shall be mixed in accordance with the proportionspecification of Specification C 270 and shall be selected onthe basis of Appendix X1 of Specification C 270.4.3 Surface bonding mortar shall meet the requir
12、ements ofSpecification C 887. If the dry mix contains hard lumps, it shallnot be used.4.4 Shims shall be corrosion-resistant metal or plastic witha minimum compressive strength of 2000 psi (13.8 MPa), orsteel protected from corrosion by a coating of zinc at least 0.8oz/ft2(2.4 gm/mm2), or by a coati
13、ng of cadmium or zinc ofequivalent corrosion resistance.5. Leveling Courses5.1 Leveling courses, when needed, are to provide a smooth1This practice is under the jurisdiction of ASTM Committee C12 on Mortars andGrouts for Unit Masonry and is the direct responsibility of Subcommittee C12.06 onSurface
14、Bonding.Current edition approved September 15, 1991. Published November 1991.Originally published as C 946 81. Last previous edition C 946 84 (1989).2Annual Book of ASTM Standards, Vol 04.05.3Discontinued. See 1989 Annual Book of ASTM Standards, Vol 04.05.4Available from the American Concrete Instit
15、ute, P.O. Box 9094, FarmingtonHills, MI 18333.5Available from the International Masonry Industry All-Weather Council,Mason Contractors Association of America, 17 W601 Fourteenth St., OakbrookTerrace, IL 60181.6Available from the National Concrete Masonry Assn., P.O. Box 781, Herndon,VA 22070.1Copyri
16、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.surface level within14 in. (6.35 mm) in 20 ft (6.1 m), for drystacking concrete masonry units. Leveling courses shall belocated whenever a vertical difference greater than12 in. (12.7mm) in 10
17、 ft (3.0 m) occurs within one course. Levelingcourses are usually located on the first course above thefoundation, because footings are not normally placed in a levelcondition, and at each floor level.5.2 When mortar or surface bonding mortar is used aleveling course, concrete masonry units shall be
18、 set in a fullbed of mortar, laid to a line with the top surface level, asdefined in 5.1, and butted together with no mortar in the headjoints. Bed joints shall be struck flush. If the cores are to begrouted, no mortar shall be placed in the space to receive grout.5.3 Allow mortar to set sufficientl
19、y so no movement breaksthe bond while dry stacking units in subsequent courses.6. Dry-Stacking Concrete Masonry Units6.1 Courses of concrete masonry units between the levelingcourses shall be placed without mortar on the bed or headjoints. Place units in running bond. Remove burrs and buttblocks tig
20、htly.6.2 Use shims, mortar, or surface bonding mortar to plumband level individual units when necessary.6.3 Check the wall every fourth course to be certain it isplumb and level. If any course is out of level by more than12in. (12.7 mm) in 10 ft (3.0 m) another leveling course shall bebuilt.6.4 Cut
21、masonry units to fit openings. Minimum length ofcut piece used in the wall shall be 114 in. (31.8 mm).6.5 Precut units for inserts indicated on drawings.6.6 Anchors, reinforcing, flashing, lintels, and other items tobe built in shall be installed as the stacking progresses. Cut ornotch masonry units
22、 as required.NOTE 2Special consideration must be given to the placement of builtin items. Surface bonding mortar requires approximately 114 in. (31.8mm) from the edge of a unit to develop tensile strength across the joint.Layout of the first course with respect to built in items is extremelyimportan
23、t, it determines the size of the cut pieces for closure.NOTE 3Utilities such as electrical lines and plumbing located in thecores of the units are best placed prior to the application of surfacebonding mortar while the concrete masonry units are visible.6.7 Cores to be filled with grout shall be ali
24、gned to providea continuous, unobstructed opening.6.8 Where a horizontal change in wall thickness occurs, thethicker portion shall end with a solid surface. Use a levelingcourse for the first course in the upper portion.NOTE 4Dry-stacked, uncoated walls should be adequately braced.7. Mixing Surface
25、Bonding Mortar7.1 Use clean mixing equipment and water free of deleteri-ous amounts of acid, alkali, and organic materials.7.2 Surface bonding mortar shall be mixed according to themanufacturers instructions and used within the time recom-mended by the manufacturer.7.3 Mix only full bag multiples of
26、 material to overcome anysegregation of ingredients while in the package.7.4 Mixing time shall be kept to a minimum, as over mixingmay cause damage to the fibers.7.5 Hand Mixing:7.5.1 Place water in the mixing container.7.5.2 Slowly add the dry surface bonding material.7.5.3 Mix thoroughly.7.6 Machi
27、ne Mixing:7.6.1 Place water in mixer.7.6.2 Add the surface bonding material to the operatingmixer.7.6.3 Mix thoroughly, 1 to 3 min after all materials havebeen added.7.7 The mixture should be creamy, nonlumpy, and easy toapply.7.8 Admixtures may be permitted within the limits set bySpecification C 8
28、87 and the manufacturer of the surfacebonding mortar. If desired, admixtures must be specified in thecontract documents.8. Application of Surface Bonding Mortar8.1 Wet the wall uniformly with water immediately beforeapplying surface bonding mortar to prevent excessive suctionof water from the surfac
29、e bonding mortar. If the wall dries priorto application, rewet it. Avoid saturating the units.8.2 Trowel- or spray-apply surface bonding mortar to bothsides of the dry-stacked concrete masonry units.8.3 Completely cover the wall surface with a minimumthickness of18 in. (3.2 mm) of surface bonding mo
30、rtar bytrowel or spray.8.4 When a second coat of surface bonding mortar is to beapplied, the first coat shall have taken its initial set but not becompletely hardened or dried out. If the first coat has com-pletely hardened or dried out, consult the manufacturersrecommendations for application of a
31、second coat, since abonding agent may be required.8.5 Finish to the texture specified.8.6 If application of surface bonding mortar is discontinuedfor more than 1 h, the horizontal joint between the twoapplications, other than at wall tops, must occur at least 114 in.(31.8 mm) from the horizontal edg
32、e of the concrete masonryunit.9. Curing and Protection9.1 Surface bonding mortar shall not be applied at tempera-tures below 40F (4.4C) unless the International MasonryIndustry All Weather Councils “Recommended Practices andGuide Specifications for Cold Weather Masonry Construction”are followed.9.2
33、Dampen the wall with a water mist after 8 h, but within24 h of application of the surface bonding mortar.9.3 Fog spray twice within the first 24 h from application ofthe surface bonding mortar. With pigmented mortar the timemay be extended to 48 h. With maximum temperature in excessof 90F (32.2C), w
34、ind speed greater than 20 mph (32.2 km/h),or mean relative humidity less than 50 % relative humidity,more frequent application of fog spray shall be necessary.9.4 The top of the walls shall be covered with a nonstaining,waterproof covering, extending at least 2 ft (0.6 m) on eachside of the wall to
35、prevent moisture from entering the wall untilthe top is permanently protected.C 946210. Other Requirements10.1 Requirements concerning grout, reinforcement, an-chors, ties, corrosion resistance, dimensional tolerances, wallbracing after coating, and miscellaneous items unless specifiedby the manufac
36、turer of the surface bonding mortar shall beoutlined in the following:10.1.1 Building Code Requirements for Concrete Structuresand Commentary by the American Concrete Institute.10.1.2 Specification for the Design and Construction ofLoad-Bearing Concrete Masonry.10.2 Control Joints:10.2.1 Location, s
37、pacing, and type of control joints shallmeet the requirements of the standards referenced in 10.1.10.2.2 Control joints shall be uniform in width, through thewall, and continuous from top to bottom of the wall.10.2.3 Remove surface bonding mortar from the controljoint.11. Keywords11.1 dry stacked; f
38、iber reinforced; mortar; packaged; surfacebondingASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights
39、, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for re
40、vision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing yo
41、u shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 9463
