1、Designation: C 1298 95 (Reapproved 2001)Standard Guide forDesign and Construction of Brick Liners for IndustrialChimneys1This standard is issued under the fixed designation C 1298; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last 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 guide covers procedures for the design, construc-tion, and serviceability of brick liners for industri
3、al chimneys.The structural design criteria are applicable to vertical masonrycantilever structures supported only at their base, either by afoundation, a concrete pedestal, or by some means from theouter concrete shell. Excluded from direct consideration aresingle-wythe, sectional brick linings that
4、 are supported on aseries of corbels cast in the outer chimney shell.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with i
5、ts use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 395 Specification for Chemical-Resistant Resin Mortars2C 466 Specific
6、ation for Chemically Setting Silicate andSilica Chemical-Resistant Mortars2C 980 Specification for Industrial Chimney Lining Brick2E 447 Test Methods for Compressive Strength of MasonryPrisms2E 111 Test Method for Youngs Modulus, Tangent Modulus,and Chord Modulus32.2 ACI Standard:30788 Practice for
7、the Design and Construction of Cast-In-Place Reinforced Concrete Chimneys42.3 ASCE Standard:ASCE 7-88 Minimum Design Loads for Buildings andOther Structures (Formerly ANSI A58.1)2.4 Other Standard:1991 Uniform Building Code, International Conference ofBuilding Code Officials, California53. Terminolo
8、gy3.1 Notations:a = brick dimension in radial direction (in.)b = brick dimension in tangential direction (in.)c = brick chamfer (in.)Ce= chimney deflection due to earthquake loads (in.)d = outside diameter of brick liner (in.)D = mean liner diameter at a given elevation (in.)Em= masonry modulus of e
9、lasticity as established by performing brick prismtest or by past experience, psifb= critical liner buckling stress, psifd= maximum vertical compressive stress due to dead load, psifde= maximum vertical compressive stress due to the combined effect ofearthquake and dead load, psifdw= maximum vertica
10、l compressive stress due to the combined effect ofwind and dead load, psifm= average ultimate masonry compressive strength established by perform-ing brick prism test or by past experience, psifv= maximum shear stress due to wind or earthquake, psiF.S. = factor of safetyh = total liner height (ft)he
11、= height of liner above elevation being checked for buckling (ft)Le= liner deflection due to earthquake loads (in.)P = constructional out-of-plumbness of liner with respect to shell (in.)r = average mean radius of liner (ft)S = shell deflection due to sun effect (in.)T = liner deflection due to diff
12、erential temperature effects (in.)t = wall thickness (in.)v = coefficient of variation in brick prism testsW = shell deflection due to design wind loads (in.)a = coefficient of thermal expansion for brick liner (use 3.5 3 106unlessotherwise established) (in./in./F)4. Significance and Use4.1 History:
13、4.1.1 For many years, brick liners have been used with anexcellent record of performance. For the most part, however,the design and construction of brick liners has been based onpast industry practice due to the lack of available informationand knowledge of the physical properties of the brick andmo
14、rtar, the thermal and seismic behavior of brick liners, andmany related characteristics that were not properly or accu-rately defined.1This guide is under the jurisdiction of ASTM Committee C15 on ManufacturedMasonry Units and is the direct responsibility of Subcommittee C15.05 on MasonryAssemblies.
15、Current edition approved June 15, 1995. Published August 1995.2Annual Book of ASTM Standards, Vol 04.05.3Annual Book of ASTM Standards, Vol 03.01.4Available from American Concrete Institute, P.O. Box 19150, Detroit, MI48219.5Available from International Conference of Building Officials, 5360 SouthWo
16、rkman Mill Road, Whittier, CA 90601.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.2 The use of scrubbers, which lower gas temperaturesand introduce highly corrosive condensates into the flue gassystem, requires many new design
17、considerations. The effectthat scrubbers have on brick liners is an ongoing area of study,since a number of liners have experienced growth- anddeflection-related problems which may be attributable, at leastin part, to nonuniform temperature and moisture conditionswithin the liners.4.2 PurposeThe rec
18、ommendations contained herein rep-resent current industry practices and serve to define thepertinent considerations that should be followed in the designand construction of brick chimney liners.5. Materials5.1 GeneralThe selection of suitable liner materials,those capable of resisting the environmen
19、t to which they willbe exposed, should be based on an evaluation of the uniqueoperating conditions that exist in each application. Although itis not the intent to restrict the applicability of this guide, andwhile other materials may be appropriate in some applications,the chemical-resistant brick a
20、nd mortar standards set forth in5.2 and 5.3 define the type of materials used in the majority ofbrick liners that are specified, designed, and erected today. Allportions of this guide reflect test data, design requirements, andother practices as they relate to these materials. The provisionsof this
21、guide should be carefully reviewed for applicability ifother materials are specified or used. Due to a greater knowl-edge of overall plant operation, material capabilities, and theflue gas environment, the owners technical representativeshould be responsible for selecting all liner materials.5.2 Bri
22、ck:5.2.1 Unless the specific application precludes their use,brick conforming to the requirements of Specification C 980should be used. Specification C 980 covers solid kiln-firedbrick made of clay, shale, or mixtures thereof.5.2.2 Three types of brick are defined in SpecificationC 980: Types I, II,
23、 and III. By definition, the brick types vary,respectively, in decreasing degrees of absorption and acidsolubility. These bricks generally are resistant to all acids andalkalies (with the exception of acid fluorides and strong, hotcaustics). Types I, II, and III brick safely will withstandcontinuous
24、 temperatures up to 750F. Generally, the bricks willwithstand short-term exposure to temperatures in excess of750F, but the capability of the bricks to resist higher tempera-tures should be studied case by case. The selection of the bricktype and the potential need for testing beyond the requirement
25、sof Specification C 980 should be determined on an individualproject basis.5.2.3 Specification C 980 brick Types I and II generally areavailable from any manufacturer who makes double-sized,kiln-fired, solid brick for corrosion-resistant applications. Thestringent requirements for Type III brick, ho
26、wever, make itmore difficult and expensive to manufacture. Consequently,availability of Type III brick is limited; therefore, beforespecifying Type III brick, determine both the necessity of itsuse and its availability.5.3 Mortar:5.3.1 Unless specific application requirements dictate oth-erwise, mor
27、tar should conform to the requirements of one ofthe brick types listed herein.5.3.1.1 Specification C 466These widely-used mortarsexhibit excellent resistance to most acids (except hydrofluoricacid), water, solvents, and temperatures to 1200F. Thesemortars are also resistant to intermittent exposure
28、 to mildalkalies, but their primary capability is resisting the strongacids commonly found in fossil-fuel flue gas environments.5.3.1.2 Specification C 395Organic resin-type mortars(such as Furan mortar) have been used in brick chimney liners,mainly due to their capacity to resist a wider variety of
29、chemicals than inorganic mortars. Generally suitable for useover a wider pH range, they resist non-oxidizing acids,alkalies, salts, water, and temperatures to 350F.5.3.1.3 High alumina cement (HAC) mortars, while notgenerally used in brick chimney linings, also are available.They are usually used in
30、 conjunction with heat-resistiveaggregates and may be suitable for some chimney applications.5.3.2 It is important to recognize that the selection of theproper mortar is essential to successful functioning of a brickliner. The various types of chemical-resistant mortars should beevaluated to determi
31、ne which is the most suitable for a givenapplication and set of operating conditions.5.4 AppurtenancesDue to the availability of a wide vari-ety of metallic materials and the great variations in the flue gasconditions to which materials are exposed, it is beyond thescope of this document to make rec
32、ommendations regardingthe suitability of materials for liner appurtenances such asbreeching ducts, bands, lintels, buckstays, hoods, caps, anddoors. The selection of these materials can be made only byevaluating the specific factors and conditions that exist on eachindividual project. One must evalu
33、ate the operating environ-ment, projected maintenance requirements, and other suchtechnical and economic evaluation factors commonly associ-ated with the process of material selection.5.5 Field TestingIf it is determined that field testing isrequired for a particular project, the test methods and ac
34、cep-tance criteria should be agreed upon mutually by the materialmanufacturers, the contractor, and the owners technical rep-resentative. Certification that the materials shipped for use onthe project conform to the requirements of their respectiveASTM specifications should be obtained from the manu
35、fac-turer.6. Construction Requirements6.1 Handling and Storage of Materials:6.1.1 Brick pallets and the individual brick units should behandled as little as possible to reduce the likelihood of crackingand chipping. While it is obviously beneficial to keep theamount of chipping and cracking to a min
36、imum, no criteriacurrently exist to evaluate what constitutes acceptability.Therefore, if deemed necessary, the specifier should includeacceptance criteria in the project specification. Cracking is notalways evident, and pallets suspected of containing crackedbrick should be checked closely by remov
37、ing individualsamples. Badly damaged or cracked brick should not be used.6.1.2 Mortar and brick should be kept dry and free fromfrost during construction. Heated storage sheds should be usedC 1298 95 (2001)2when the ambient temperature during construction is below40F (4C) unless otherwise recommende
38、d by the manufactur-ers of the brick or mortar.6.2 Brick Sizing:6.2.1 It is standard industry practice to use chamfered brickto approximate the circular liner shape. The proper chamfer-to-diameter relationship is shown in Fig. 1. In certain cases, itmay be necessary to use two or more chamfers for a
39、 liner witha larger change in diameter over its height. The proper chamferwill keep mortar joint size variation to a minimum, resulting intight, acid-resistant vertical seams.6.2.2 Double-sized brick, typically 334 by 412 by 8 in., isused in brick liner construction, although any other brick sizetha
40、t meets the recommendations of this guide is acceptable.6.3 Brick Bonding:6.3.1 The use of proper brick bonding techniques inhibitsdelamination, resulting in stronger, more crack-resistant walls.A proper brick bond will limit the propagation of cracks.6.3.2 To minimize the effects of tolerance diffe
41、rences be-tween“ stretchers” (brick laid in the circumferential direction)and“ headers” (brick laid in the radial direction), it is beneficialto reverse the brick bond frequently. As a minimum require-ment, the brick bond for all wall thicknesses should bereversed, or staggered, after every three co
42、urses.6.3.3 Circumferentially, brick should be staggered fromcourse to course to prevent the stacking of vertical joints. Sincebrick liners are commonly tapered, occasional vertical align-ment of radial joint will inevitably occur and is consideredacceptable practice.6.4 Mortar Usage:6.4.1 Mortar sh
43、ould be stored and used in accordance withthe manufacturers recommendations. Mortar manufacturersgenerally make representatives available to assist field person-nel during initial mixing and material handling operations.6.4.2 Chemically-setting mortars typically used in brickliners are sensitive to
44、changes in temperature and humidity, andsmall variations in mix proportions. The builder should moni-tor the mortar consistency during the course of construction.Any changes in the visual appearance of the mortar, or changesin handling, mixing, and setting characteristics immediatelyshould be brough
45、t to the attention of the manufacturer.6.4.3 The working time for a chemically-setting mortar isshort compared to that for a portland cement mortar. Onlymortar quantities that can be used within their working timeshould be mixed, since retempering of these mortars is notrecommended by the manufactur
46、ers.6.4.4 All brick in the masonry chimney lining should be laidwith full-bed, circumferential, and radial mortar joints. Mortarshall be applied to the brick by the use of a trowel. All mortarjoints on the interior surface of the liner shall be trowel-struck.6.5 Rate of ConstructionA typical liner i
47、s constructedfrom a multiple-point suspension scaffold, which facilitates afast rate of construction, even to the point of making it possibleto build greater heights of freshly laid masonry than iswarranted by the setting rate of the mortar. This is particularlytrue when constructing small diameter
48、liners when the ambienttemperature is low. Building at a rate faster than is warrantedby the setting characteristics of the mortar can result inpremature cracking and deformation of the lining. The rate ofbrick laying and the mortar set time should be monitored sothat partially set masonry is not da
49、maged and tolerances aremaintained.6.6 Banding:6.6.1 For optimum performance, the bands should be in-stalled snugly around the liner, recognizing that some circum-ferential expansion will occur under thermal loading. Thebands should be positioned either by the use of verticalsupports or by placing the band on offset brick. The brickshould then be laid directly against the pre-positioned band.Applied alone, this method of band installation should yieldadequate contact between the brick and the band around thefull circumference. Provided such a method and good constru
