1、Designation: C1791 15C1791 16Standard 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
2、last revision. 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 efflorescence potential in new unit pavement systems.1.2 The values stated in
3、inch-pound units are to be regarded as the standard. The SI units given in parentheses are forinformation only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safe
4、ty and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:C67 Test Methods for Sampling and Testing Brick and Structural Clay TileC270 Specification for Mortar for Unit MasonryC1180 Terminology of Mortar and Grout for Unit
5、 MasonryC1232 Terminology of Masonry3. Terminology3.1 Definitions:3.1.1 Terminology defined in Terminologies C1180 and C1232 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 pa
6、vement system materials.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 be efflorescence, stains produced by acid-soluble vanadium compounds in clay masonry are usually yellowor g
7、reen; and stains produced by acid-soluble manganese compounds are usually brown or gray.3.2.3 jointing material, nmortar, aggregate, sealant, or other materials used between paver units.3.2.4 unit pavement system, na system consisting of edge restraint, wearing course of discrete clay or concrete pa
8、vers, settingbed, jointing material, base or sub-base, or combination thereof, and appropriate drainage elements.3.2.4.1 DiscussionFlexible pavement is a unit pavement system whose wearing course consists of discrete clay or concrete pavers on an aggregatebase, an aggregate base stabilized with asph
9、alt or cement, or asphalt pavement.1 This test method is under the jurisdiction ofASTM Committee C15 on Manufactured Masonry Units and is the direct responsibility of Subcommittee C15.05 on MasonryAssemblies.Current edition approved July 1, 2015Aug. 1, 2016. Published July 2015August 2016. Originall
10、y approved in 2014. Last previous edition approved in 20142015 as C179114a.15. DOI: 10.1520/C1791-15.10.1520/C1791-16.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may
11、 not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the
12、 end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.4.2 DiscussionRigid pavement is a unit pavement system whose surface wearing course consists of discrete clay or concrete units on a rigid basesuch as concrete.4
13、. Significance and Use4.1 This guide provides information that, if implemented, will reduce efflorescence potential in new unit pavement systems.However, its implementation will not always completely prevent efflorescence.4.2 This guide may be augmented by related information contained in the append
14、ixes of Specification C270, the additionalmaterial listed in Appendix X1 in this standard, and other publications.5. Principles of Efflorescence5.1 Efflorescence is directly related to the quantity of water-soluble compounds within, or exposed to, a unit pavement system;and to the quantity of water
15、exposed to these compounds. Water-soluble compounds or water causing efflorescence may be fromadjacent surfaces or beneath the pavement system: for example, fertilizer in runoff from adjacent flower beds or lawns; groundwater evaporating through the wearing course; water-soluble compounds leaching o
16、ut of crushed recycled concrete used inpavement bases; and water from sprinkler systems and roofs. Since neither water nor water-soluble compounds can be completelyeliminated from unit pavement systems, the potential for efflorescence is reduced by reducing water-soluble compounds and waterretained
17、within the unit pavement system.5.2 Water can penetrate through joints in the surface of unit pavement 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 unit pavement system, the water w
18、ill dissolve water-soluble compounds thatmay exist in the paver units, mortar components, grout, setting bed, concrete slab, admixtures or other secondary sources, and maydeposit them on the exterior surface of the unit pavement system when it migrates to the surface and through evaporation. Thepres
19、ence of a concrete slab below sand setting beds in unit pavement system allows water to remain on top of the slab where itcan more readily dissolve water-soluble compounds in the concrete.5.4 The most common efflorescence deposits contain two or more of the following: potassium, sodium, calcium, sul
20、fates,carbonates, bicarbonates, chlorides, and hydroxides.5.5 Some water-soluble compounds deposited on the surface of unit pavement systems can chemically react to form compoundsthat are not water-soluble. Calcium carbonate (CaCO3) deposits on unit pavement system are a fairly common example. They
21、area result of reaction between the efflorescence compound calcium hydroxide and carbon dioxide after the calcium hydroxide isdeposited on the surface of the pavement and is exposed to the air.5.6 Under some circumstances, particularly when exterior coatings are present, efflorescence compounds can
22、be depositedbelow the surface of the paver units. This condition is called cryptoflorescence. When cryptoflorescence occurs, the forces resultingfrom its confinement can cause disintegration of pavement surfaces.6. Reduction of Efflorescence Potential in New Pavements6.1 Efflorescence on new unit pa
23、vement systems is reduced when water penetration of the pavement is minimized; when waterthat penetrates pavement is quickly drained from the pavement; when contact between dissimilar paver units is minimized; whenpotential efflorescence compounds in the pavement system materials are minimized; and
24、when exposure of the pavement topotential efflorescence causing compounds is minimized.6.2 The amount of water from precipitation and other sources that is able to penetrate a unit pavement system is minimized by:6.2.1 A minimum surface slope to drain of 14 in./ft (20 mm/m).6.2.2 Good bond and full
25、contact between paver units and mortar in masonry pavements. This condition is achieved by usingmortar that is compatible with the paver units; completely filled mortar joints; compacted concave, V, or grapevine mortar joints;cold weather construction practices that prevent masonry materials from fr
26、eezing.6.2.3 Construction practices that protect uncompleted unit pavement systems from rain or snow during construction.6.2.4 Properly sized and located movement joints in the pavement and in rigid bases such as concrete.6.2.5 Gutters, overhangs, and canopies to protect the pavement from rain.6.2.6
27、 Utilization of For concrete paving units, utilization of integral efflorescence controlling compounds in the units orcompatible applied water repellent sealer on the surface of unit pavement systems or integral efflorescence controlling admixturesin paver units when specified.pavement, or both.6.2.
28、7 Utilization of compatible integral water repellent admixtures and mortar modifiers.6.3 Water that penetrates a unit pavement system is quickly drained out of the system by:6.3.1 The use of a drainage system that conveys water to low points and allows water to be conveyed out of the pavementsystem.
29、C1791 1626.3.2 Drainage holes through the slab base at the low points in systems that are installed over slab bases to drain water off theslab base.6.4 Contact between dissimilar paver units is minimized by:6.4.1 The use of a separator between changes in paver materials in unit pavement systems.6.5
30、Potential efflorescence compounds in the pavement system materials can be minimized by:6.5.1 Preconstruction testing of all unit pavement system materials, water, cleaning agents, deicing chemicals, and admixturesto be used to evaluate their potential to contribute to efflorescence. The results of t
31、hese tests should be evaluated together with theinfluence of construction practices and design in predicting efflorescence potential in pavements. Available preconstruction testsinclude: Test Method C67 efflorescence test for brick; chemical analysis of cements to determine water soluble alkali (Na2
32、O K2O)content; chemical analysis of hydrated lime to determine calcium sulfate content; and chemical analysis of sand, water, admixturesand cleaning agents to determine alkali, chloride, and sulfate content. Presently, there is no ASTM efflorescence test for concretepaver units or mortar. The potent
33、ial for efflorescence increases with increasing amounts of water-soluble alkali, chlorides, andsulfates in segmental and masonry pavement materials.6.5.2 Storage and protection of all unit pavement system materials prior to use to prevent contact with dissimilar materials andto protect materials fro
34、m moisture.6.5.3 Protection of all unit pavement system materials during transportation when there is a probability of contamination fromroad salts, fertilizers, and airborne contaminants.6.5.4 Utilization of proper cleaning materials and procedures on new unit pavement systems.6.5.5 Not using crush
35、ed recycled concrete in pavement bases where drainage is poor or high ground water conditions exist.6.6 Exposure of unit pavement systems to potential efflorescence causing compounds is minimized by:6.6.1 Minimizing the use of deicing chemicals.6.6.2 Minimizing water runoff from adjacent flower beds
36、 or lawns on the pavement.7. Keywords7.1 drainage; efflorescence; mortar; paving units; percolate; preconstruction testing; water penetrationAPPENDIX(Nonmandatory Information)X1. ADDITIONAL MATERIALX1.1 Application Guide for Interlocking Concrete Pavers, Tech Spec Number 10, Interlocking Concrete Pa
37、vement Institute,Herndon, VA.X1.2 Bedding Sand Selection for Interlocking Concrete Pavements in VehicularApplications, Tech Spec Number 17, InterlockingConcrete Pavement Institute, Herndon, VA.X1.3 Brick in Landscape Architecture-Pedestrian Applications, Technical Notes 29, Brick Institute of Americ
38、a, Reston, VA, July,1994.X1.4 Chin, I. R., and Petry, L., “Design and Testing to Reduce 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 Societyfor Testing and Materials, Phil
39、adelphia, 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,” Technical Notes 23, Brick Industry Association, Reston, VA, June, 2006.X1.7 “EfflorescenceCauses and Prevention,” T
40、echnical Notes 23A, Brick Industry Association, Reston, VA, June, 2006.C1791 163X1.8 Guide Specification for the Construction of Interlocking Concrete Pavement, Tech Spec Number 9, Interlocking ConcretePavement Institute, Herndon, VA.X1.9 Paving Systems Using Clay Pavers, Technical Notes 14, Brick I
41、ndustry Association, Reston, VA, March 2007.X1.10 Paving Systems Using Clay Pavers on a Sand Setting Bed, Technical Notes 14A, Brick Industry Association, Reston, VA,October, 2007.X1.11 Paving Systems Using Clay Pavers on a Bituminous Setting Bed, Technical Notes 14B, Brick IndustryAssociation, Rest
42、on,VA, June, 2010.X1.12 Paving Systems Using Clay Pavers on a Mortar Setting Bed, Technical Notes 14C, Brick IndustryAssociation, Reston, VA,July, 2011.X1.13 Permeable Clay Brick Pavements, Technical Notes 14D, Brick Industry Association, Reston, VA, February, 2012.X1.14 Structural Design of Interlo
43、cking Concrete Pavements for Roads and Parking Lots, Tech Spec Number 4, InterlockingConcrete Pavement Institute, Herndon, VA.X1.15 “Trowel Tips: Efflorescence,” 1S239, Portland Cement Association, Skokie, IL, 1991.SUMMARY OF CHANGESCommittee C15 has identified the location of selected changes to th
44、is standard since the last issue (C1791 14a)15) that may impact the use of this standard. (July(August 1, 2015)2016)(1) Revised 5.1 and 6.2.6.(2) Added 6.3.26.5.5.Committee C15 has identified the location of selected changes to this standard since the last issue (C1791 14)14a) that may impact the us
45、e of this standard. (December(July 1, 2014)2015)(1) Revised Added 3.2.36.3.2, 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 t
46、his standard are expressly advised that determination 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 y
47、ears andif not revised, either reapproved or withdrawn.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 commi
48、ttee, which you may attend. If you feel that your 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 194
49、28-2959,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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 164
