1、Designation: C1791 14aStandard 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 re
2、vision. 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-pou
3、nd 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 he
4、alth 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 Masonry
5、C1232 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 sy
6、stemmaterials.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
7、stainsproduced 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 b
8、ed, 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
10、new 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. P
11、rinciples 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 b
12、eneath 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.Cu
14、rrent edition approved Dec. 1, 2014. Published December 2014. Originallyapproved in 2014. Last previous edition approved in 2014 as C1791 14. DOI:10.1520/C1791-14A.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West
15、Conshohocken, 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, th
16、e water 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.
17、 The 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, calciu
18、m, sulfates,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
19、. They 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
20、 can 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 uni
21、t pavement 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
22、 when 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 cont
23、act 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 freezin
24、g.6.2.3 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 Utili
25、zation 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
26、 is 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.6.4 Contact between dissimilar paver units is minimized by:6.4.1 The use of a separator between changes in pavermaterials in unit pavem
27、ent systems.6.5 Potential efflorescence compounds in the pavementsystem materials can be minimized by:6.5.1 Preconstruction testing of all unit pavement systemmaterials, water, cleaning agents, deicing chemicals, and ad-mixtures to be used to evaluate their potential to contribute toefflorescence. T
28、he results of these tests should be evaluatedtogether with the influence of construction practices and designin predicting efflorescence potential in pavements. Availablepreconstruction tests include: Test Method C67 efflorescencetest for brick; chemical analysis of cements to determine watersoluble
29、 alkali (Na2OK2O) content; chemical analysis ofhydrated lime to determine calcium sulfate content; andchemical analysis of sand, water, admixtures and cleaningagents to determine alkali, chloride, and sulfate content.Presently, there is no ASTM efflorescence test for concretepaver units or mortar. T
30、he potential for efflorescence increaseswith increasing amounts of water-soluble alkali, chlorides, andsulfates in segmental and masonry pavement materials.6.5.2 Storage and protection of all unit pavement systemmaterials prior to use to prevent contact with dissimilarmaterials and to protect materi
31、als from moisture.6.5.3 Protection of all unit pavement system materialsduring transportation when there is a probability of contami-nation from road salts, fertilizers, and airborne contaminants.6.5.4 Utilization of proper cleaning materials and proce-dures on new unit pavement systems.6.6 Exposure
32、 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 from adjacent flower beds orlawns on the pavement.7. Keywords7.1 drainage; efflorescence; mortar; paving units; percolate;preconstructio
33、n testing; water penetrationC1791 14a2APPENDIX(Nonmandatory Information)X1. ADDITIONAL MATERIALX1.1 Application Guide for Interlocking Concrete Pavers,Tech Spec Number 10, Interlocking Concrete PavementInstitute, Herndon, VA.X1.2 Bedding Sand Selection for Interlocking ConcretePavements in Vehicular
34、 Applications, Tech Spec Number 17,Interlocking Concrete Pavement Institute, Herndon, VA.X1.3 Brick in Landscape Architecture-PedestrianApplications, Technical Notes 29, Brick Institute of America,Reston, VA, July, 1994.X1.4 Chin, I. R., and Petry, L., “Design and Testing toReduce Efflorescence Pote
35、ntial 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 Testing and Materials, Philadelphia,1993, pp. 317.X1.5 “Control and Removal of Efflorescence,” NCMA-TEK 8-3A, National Concrete Masonr
36、y Association, Herndon,VA, 2003.X1.6 “StainsIdentification and Prevention,” TechnicalNotes 23, Brick Industry Association, Reston, VA, June, 2006.X1.7 “EfflorescenceCauses and Prevention,” TechnicalNotes 23A, Brick Industry Association, Reston, VA, June,2006.X1.8 Guide Specification for the Construc
37、tion of Interlock-ing Concrete Pavement, Tech Spec Number 9, InterlockingConcrete Pavement Institute, Herndon, VA.X1.9 Paving Systems Using Clay Pavers, Technical Notes14, Brick Industry Association, Reston, VA, March 2007.X1.10 Paving Systems Using Clay Pavers on a Sand SettingBed, Technical Notes
38、14A, Brick IndustryAssociation, Reston,VA, October, 2007.X1.11 Paving Systems Using Clay Pavers on a BituminousSetting Bed, Technical Notes 14B, Brick Industry Association,Reston, VA, June, 2010.X1.12 Paving Systems Using Clay Pavers on a MortarSetting Bed, Technical Notes 14C, Brick Industry Associ
39、ation,Reston, VA, July, 2011.X1.13 Permeable Clay Brick Pavements, Technical Notes14D, Brick Industry Association, Reston, VA, February, 2012.X1.14 Structural Design of Interlocking Concrete Pave-ments for Roads and Parking Lots, Tech Spec Number 4,Interlocking Concrete Pavement Institute, Herndon,
40、VA.X1.15 “Trowel Tips: Efflorescence,” 1S239, Portland Ce-ment Association, Skokie, IL, 1991.SUMMARY OF CHANGESCommittee 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)(1) Revised 3.2.3,
41、 5.1, 6.2.4, 6.2.5, and Section 7. (2) Deleted X1.4, X1.7, and X1.8.ASTM 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
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