1、Designation: C1791 14Standard 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. Scope1.1 This guide covers methods for reducing efflorescencepotential in new unit pavement systems.1.2 The values stated in inch-pound
3、 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 heal
4、th 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 MasonryC1
5、232 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 syst
6、emmaterials.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 st
7、ainsproduced by acid-soluble manganese compounds are usuallybrown or gray.3.2.3 jointing material, nmortar, aggregate, or sealantused between paver units.3.2.4 unit pavement system, na system consisting of edgerestraint, wearing course of discrete clay or concrete pavers,setting bed, jointing materi
8、al, 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 asphalt pavement.3
9、.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 new unit pavementsy
10、stems. 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. Principles of Efflor
11、escence5.1 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 beneath the pave-men
12、t system: for example, fertilizer in runoff from adjacentflower beds or lawns; ground water evaporating through thewearing course. Since neither water nor water-soluble com-pounds can be completely eliminated from unit pavementsystems, the potential for efflorescence is reduced by reducingwater-solu
13、ble compounds and water retained within the unitpavement system.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.Current edition approved March 1, 2014. Published March 2014. DO
14、I: 10.1520/C1791-14.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West 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
15、jointing material.5.3 If a significant amount of water penetrates a unitpavement system, the 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
16、 surface of theunit pavement system when it migrates to the surface andthrough evaporation. 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 c
17、ommon efflorescence deposits contain two ormore of the following: potassium, sodium, calcium, 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-solu
18、ble. Calcium carbonate(CaCO3) deposits on unit pavement system are a fairly com-mon example. 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
19、some circumstances, particularly when exteriorcoatings are present, efflorescence compounds 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 s
20、urfaces.6. Reduction of Efflorescence Potential in NewPavements6.1 Efflorescence on new unit 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
21、; when potential efflorescence compounds in thepavement system materials are minimized; and 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 b
22、y:6.2.1 A minimum surface slope to drain of14 in./ft (20mm/m).6.2.2 Good bond and full contact 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 grapevinemo
23、rtar joints; cold weather construction practices that preventmasonry materials from freezing.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.6.2.5 Overhangs and canopies t
24、o protect the pavement fromrain.6.2.6 Utilization 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 W
25、ater that penetrates a unit pavement system 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 betw
26、een 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 systemmaterials, water, cleaning agents, deicing chemicals, and ad-mixtures to be used to evaluate their
27、 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. Availablepreconstruction tests include: Test Method C67 efflorescencetest for brick; chemical an
28、alysis 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 to determine alkali, chloride, and sulfate content.Presently, there is no ASTM efflorescenc
29、e 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 Storage and protection of all unit pavement systemmaterials prior to use to prevent contact wit
30、h 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, fertilizers, and airborne contaminants.6.5.4 Utilization of proper cleaning materials and proce-dure
31、s 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 from adjacent flower beds orlawns on the pavement.7. Keywords7.1 efflorescence; mortar; pavin
32、g units; percolate; precon-struction testingwater penetrationC1791 142APPENDIX(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 Interlockin
33、g ConcretePavements in Vehicular 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 Brownell, Wayne E., “The Causes and Control
34、 ofEfflorescence on Brickwork,” Research Report Number 15,Structural Clay Products Institute, McLean, VA, August 1969.X1.5 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,
35、 J. M. Melander and L. R. Lauersdorf, Eds.,American Society for Testing and Materials, Philadelphia,1993, pp. 317.X1.6 “Control and Removal of Efflorescence,” NCMA-TEK 8-3A, National Concrete Masonry Association, Herndon,VA, 1996.X1.7 “Efflorescence Causes and Mechanisms, Part I of II,”Technical Not
36、es 23 (revised), Brick Institute of America,Reston, VA, May 1985.X1.8 “Efflorescence Prevention and Control, Part II of II,”Technical Notes 23A (revised), Brick Institute of America,Reston, VA, June 1985.X1.9 Guide Specification for the Construction of Interlock-ing Concrete Pavement, Tech Spec Numb
37、er 9, InterlockingConcrete Pavement Institute, Herndon, VA.X1.10 Paving Systems Using Clay Pavers, Technical Notes14, Brick Industry Association, Reston, VA, March 2007.X1.11 Paving Systems Using Clay Pavers on a Sand SettingBed, Technical Notes 14A, Brick Industry Association, Reston,VA, October, 2
38、007.X1.12 Paving Systems Using Clay Pavers on a BituminousSetting Bed, Technical Notes 14B, Brick Industry Association,Reston, VA, June, 2010.X1.13 Paving Systems Using Clay Pavers on a MortarSetting Bed, Technical Notes 14C, Brick Industry Association,Reston, VA, July, 2011.X1.14 Permeable Clay Bri
39、ck Pavements, Technical Notes14D, Brick Industry Association, Reston, VA, February, 2012.X1.15 Structural Design of Interlocking Concrete Pave-ments for Roads and Parking Lots, Tech Spec Number 4,Interlocking Concrete Pavement Institute, Herndon, VA.X1.16 “Trowel Tips: Efflorescence,” 1S239, Portlan
40、d Ce-ment Association, Skokie, IL, 1991.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 such patent rights, and the
41、 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 revision of
42、 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 you shouldm
43、ake 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C1791 143
