1、Designation: C1791 15Standard Guide forReduction of Efflorescence Potential in New Unit PavementSystems1This standard is issued under the fixed designation C1791; 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.1. Scope*1.1 This guide covers methods for reducing efflorescencepotential in new unit pavement systems.1.2 The values stated in inch-poun
3、d units are to be regardedas the standard. The SI units given in parentheses are forinformation 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 safety and hea
4、lth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C67 Test Methods for Sampling and Testing Brick andStructural Clay TileC270 Specification for Mortar for Unit MasonryC1180 Terminology of Mortar and Grout for Unit MasonryC
5、1232 Terminology of Masonry3. Terminology3.1 Definitions:3.1.1 Terminology defined in Terminologies C1180 andC1232 shall apply in this guide.3.2 Definitions of Terms Specific to This Standard:3.2.1 cryptoflorescence, na crystalline deposit of water-soluble compounds in the pores of unit pavement sys
6、temmaterials.3.2.2 efflorescence, na crystalline deposit, usually white,of water-soluble compounds on the surface of a unit pavementsystem.3.2.2.1 DiscussionWhile not considered to beefflorescence, stains produced by acid-soluble vanadium com-pounds in clay masonry are usually yellow or green; and s
7、tainsproduced by acid-soluble manganese compounds are usuallybrown or gray.3.2.3 jointing material, nmortar, aggregate, sealant, orother materials used between paver units.3.2.4 unit pavement system, na system consisting of edgerestraint, wearing course of discrete clay or concrete pavers,setting be
8、d, jointing material, base or sub-base, or combinationthereof, and appropriate drainage elements.3.2.4.1 DiscussionFlexible pavement is a unit pavementsystem whose wearing course consists of discrete clay orconcrete pavers on an aggregate base, an aggregate basestabilized with asphalt or cement, or
9、asphalt pavement.3.2.4.2 DiscussionRigid pavement is a unit pavementsystem whose surface wearing course consists of discrete clayor concrete units on a rigid base such as concrete.4. Significance and Use4.1 This guide provides information that, if implemented,will reduce efflorescence potential in n
10、ew unit pavementsystems. However, its implementation will not always com-pletely prevent efflorescence.4.2 This guide may be augmented by related informationcontained in the appendixes of Specification C270, the addi-tional material listed in Appendix X1 in this standard, andother publications.5. Pr
11、inciples of Efflorescence5.1 Efflorescence is directly related to the quantity ofwater-soluble compounds within, or exposed to, a unit pave-ment system; and to the quantity of water exposed to thesecompounds. Water-soluble compounds or water causing efflo-rescence may be from adjacent surfaces or be
12、neath the pave-ment system: for example, fertilizer in runoff from adjacentflower beds or lawns; ground water evaporating through thewearing course; and water from sprinkler systems and roofs.Since neither water nor water-soluble compounds can becompletely eliminated from unit pavement systems, the
13、poten-tial for efflorescence is reduced by reducing water-solublecompounds and water retained within the unit pavementsystem.1This test method is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.05 on Masonry Assemblies.Cur
14、rent edition approved July 1, 2015. Published July 2015. Originally approvedin 2014. Last previous edition approved in 2014 as C1791 14a. DOI: 10.1520/C1791-15.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons
15、hohocken, PA 19428-2959. United States15.2 Water can penetrate through joints in the surface of unitpavement systems. It can penetrate voids in the mortar joints orthe interface between the paver unit and jointing material.5.3 If a significant amount of water penetrates a unitpavement system, the wa
16、ter will dissolve water-soluble com-pounds that may exist in the paver units, mortar components,grout, setting bed, concrete slab, admixtures or other secondarysources, and may deposit them on the exterior surface of theunit pavement system when it migrates to the surface andthrough evaporation. The
17、 presence of a concrete slab belowsand setting beds in unit pavement system allows water toremain on top of the slab where it can more readily dissolvewater-soluble compounds in the concrete.5.4 The most common efflorescence deposits contain two ormore of the following: potassium, sodium, calcium, s
18、ulfates,carbonates, bicarbonates, chlorides, and hydroxides.5.5 Some water-soluble compounds deposited on the sur-face of unit pavement systems can chemically react to formcompounds that are not water-soluble. Calcium carbonate(CaCO3) deposits on unit pavement system are a fairly com-mon example. Th
19、ey are a result of reaction between theefflorescence compound calcium hydroxide and carbon dioxideafter the calcium hydroxide is deposited on the surface of thepavement and is exposed to the air.5.6 Under some circumstances, particularly when exteriorcoatings are present, efflorescence compounds can
20、 be depos-ited below the surface of the paver units. This condition iscalled cryptoflorescence. When cryptoflorescence occurs, theforces resulting from its confinement can cause disintegrationof pavement surfaces.6. Reduction of Efflorescence Potential in NewPavements6.1 Efflorescence on new unit pa
21、vement systems is reducedwhen water penetration of the pavement is minimized; whenwater that penetrates pavement is quickly drained from thepavement; when contact between dissimilar paver units isminimized; when potential efflorescence compounds in thepavement system materials are minimized; and whe
22、n exposureof the pavement to potential efflorescence causing compoundsis minimized.6.2 The amount of water from precipitation and othersources that is able to penetrate a unit pavement system isminimized by:6.2.1 A minimum surface slope to drain of14 in./ft (20mm/m).6.2.2 Good bond and full contact
23、between paver units andmortar in masonry pavements. This condition is achieved byusing mortar that is compatible with the paver units; com-pletely filled mortar joints; compacted concave, V, or grapevinemortar joints; cold weather construction practices that preventmasonry materials from freezing.6.
24、2.3 Construction practices that protect uncompleted unitpavement systems from rain or snow during construction.6.2.4 Properly sized and located movement joints in thepavement and in rigid bases such as concrete.6.2.5 Gutters, overhangs, and canopies to protect the pave-ment from rain.6.2.6 Utilizati
25、on of compatible applied water repellent onthe surface of unit pavement systems or integral efflorescencecontrolling admixtures in paver units when specified.6.2.7 Utilization of compatible integral water repellent ad-mixtures and mortar modifiers.6.3 Water that penetrates a unit pavement system is
26、quicklydrained out of the system by:6.3.1 The use of a drainage system that conveys water tolow points and allows water to be conveyed out of thepavement system.6.3.2 Drainage holes through the slab base at the low pointsin systems that are installed over slab bases to drain water offthe slab base.6
27、.4 Contact between dissimilar paver units is minimized by:6.4.1 The use of a separator between changes in pavermaterials in unit pavement systems.6.5 Potential efflorescence compounds in the pavementsystem materials can be minimized by:6.5.1 Preconstruction testing of all unit pavement systemmateria
28、ls, water, cleaning agents, deicing chemicals, and ad-mixtures to be used to evaluate their potential to contribute toefflorescence. The results of these tests should be evaluatedtogether with the influence of construction practices and designin predicting efflorescence potential in pavements. Avail
29、ablepreconstruction tests include: Test Method C67 efflorescencetest for brick; chemical analysis of cements to determine watersoluble alkali (Na2OK2O) content; chemical analysis ofhydrated lime to determine calcium sulfate content; andchemical analysis of sand, water, admixtures and cleaningagents
30、to determine alkali, chloride, and sulfate content.Presently, there is no ASTM efflorescence test for concretepaver units or mortar. The potential for efflorescence increaseswith increasing amounts of water-soluble alkali, chlorides, andsulfates in segmental and masonry pavement materials.6.5.2 Stor
31、age and protection of all unit pavement systemmaterials prior to use to prevent contact with dissimilarmaterials and to protect materials from moisture.6.5.3 Protection of all unit pavement system materialsduring transportation when there is a probability of contami-nation from road salts, fertilize
32、rs, and airborne contaminants.6.5.4 Utilization of proper cleaning materials and proce-dures on new unit pavement systems.6.6 Exposure of unit pavement systems to potential efflo-rescence causing compounds is minimized by:6.6.1 Minimizing the use of deicing chemicals.6.6.2 Minimizing water runoff fr
33、om adjacent flower beds orlawns on the pavement.7. Keywords7.1 drainage; efflorescence; mortar; paving units; percolate;preconstruction testing; water penetrationC1791 152APPENDIX(Nonmandatory Information)X1. ADDITIONAL MATERIALX1.1 Application Guide for Interlocking Concrete Pavers,Tech Spec Number
34、 10, Interlocking Concrete PavementInstitute, Herndon, VA.X1.2 Bedding Sand Selection for Interlocking ConcretePavements in Vehicular Applications, Tech Spec Number 17,Interlocking Concrete Pavement Institute, Herndon, VA.X1.3 Brick in Landscape Architecture-PedestrianApplications, Technical Notes 2
35、9, Brick Institute of America,Reston, VA, July, 1994.X1.4 Chin, I. R., and Petry, L., “Design and Testing toReduce Efflorescence Potential in New Brick Masonry Walls,”Masonry: Design and Construction, Problems and Repair,ASTM STP 1180, J. M. Melander and L. R. Lauersdorf, Eds.,American Society for T
36、esting and Materials, Philadelphia,1993, pp. 317.X1.5 “Control and Removal of Efflorescence,” NCMA-TEK 8-3A, National Concrete Masonry Association, Herndon,VA, 2003.X1.6 “StainsIdentification and Prevention,” TechnicalNotes 23, Brick Industry Association, Reston, VA, June, 2006.X1.7 “EfflorescenceCa
37、uses and Prevention,” TechnicalNotes 23A, Brick Industry Association, Reston, VA, June,2006.X1.8 Guide Specification for the Construction of Interlock-ing Concrete Pavement, Tech Spec Number 9, InterlockingConcrete Pavement Institute, Herndon, VA.X1.9 Paving Systems Using Clay Pavers, Technical Note
38、s14, Brick Industry Association, Reston, VA, March 2007.X1.10 Paving Systems Using Clay Pavers on a Sand SettingBed, Technical Notes 14A, Brick IndustryAssociation, Reston,VA, October, 2007.X1.11 Paving Systems Using Clay Pavers on a BituminousSetting Bed, Technical Notes 14B, Brick Industry Associa
39、tion,Reston, VA, June, 2010.X1.12 Paving Systems Using Clay Pavers on a MortarSetting Bed, Technical Notes 14C, Brick Industry Association,Reston, VA, July, 2011.X1.13 Permeable Clay Brick Pavements, Technical Notes14D, Brick Industry Association, Reston, VA, February, 2012.X1.14 Structural Design o
40、f Interlocking Concrete Pave-ments for Roads and Parking Lots, Tech Spec Number 4,Interlocking Concrete Pavement Institute, Herndon, VA.X1.15 “Trowel Tips: Efflorescence,” 1S239, Portland Ce-ment Association, Skokie, IL, 1991.SUMMARY OF CHANGESCommittee C15 has identified the location of selected ch
41、anges to this standard since the last issue (C1791 14a) that may impact the use of this standard. (July 1, 2015)(1) Added 6.3.2.Committee C15 has identified the location of selected changes to this standard since the last issue (C1791 14) that may impact the use of this standard. (December 1, 2014)(
42、1) Revised 3.2.3, 5.1, 6.2.4, 6.2.5, and Section 7. (2) Deleted X1.4, X1.7, and X1.8.C1791 153ASTM 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 determinat
43、ion of the validity of any such patent rights, 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 withd
44、rawn. Your comments are invited either for revision 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
45、 comments have not received a fair hearing you 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 (singl
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