ASTM C1791-16(2021)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1791 − 16 (Reapproved 2021)
Standard Guide for
Reduction of Efflorescence Potential in New Unit Pavement
Systems
This standard is issued under the fixed designation C1791; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.2 efflorescence, n—a crystalline deposit, usually white,
of water-soluble compounds on the surface of a unit pavement
1.1 This guide covers methods for reducing efflorescence
system.
potential in new unit pavement systems.
3.2.2.1 Discussion—While not considered to be
1.2 The values stated in inch-pound units are to be regarded
efflorescence, stains produced by acid-soluble vanadium com-
as the standard. The SI units given in parentheses are for
pounds in clay masonry are usually yellow or green; and stains
information only.
produced by acid-soluble manganese compounds are usually
1.3 This standard does not purport to address all of the
brown or gray.
safety concerns, if any, associated with its use. It is the
3.2.3 jointing material, n—mortar, aggregate, sealant, or
responsibility of the user of this standard to establish appro-
other materials used between paver units.
priate safety, health, and environmental practices and deter-
3.2.4 unit pavement system, n—a system consisting of edge
mine the applicability of regulatory limitations prior to use.
restraint, wearing course of discrete clay or concrete pavers,
1.4 This international standard was developed in accor-
setting bed, jointing material, base or sub-base, or combination
dance with internationally recognized principles on standard-
thereof, and appropriate drainage elements.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3.2.4.1 Discussion—Flexible pavement is a unit pavement
mendations issued by the World Trade Organization Technical
system whose wearing course consists of discrete clay or
Barriers to Trade (TBT) Committee.
concrete pavers on an aggregate base, an aggregate base
stabilized with asphalt or cement, or asphalt pavement.
2. Referenced Documents
3.2.4.2 Discussion—Rigid pavement is a unit pavement
2.1 ASTM Standards:
system whose surface wearing course consists of discrete clay
C67/C67M Test Methods for Sampling and Testing Brick or concrete units on a rigid base such as concrete.
and Structural Clay Tile
4. Significance and Use
C270 Specification for Mortar for Unit Masonry
C1180 Terminology of Mortar and Grout for Unit Masonry
4.1 This guide provides information that, if implemented,
C1232 Terminology for Masonry
will reduce efflorescence potential in new unit pavement
systems. However, its implementation will not always com-
3. Terminology
pletely prevent efflorescence.
3.1 Definitions:
4.2 This guide may be augmented by related information
3.1.1 Terminology defined in Terminologies C1180 and
contained in the appendixes of Specification C270, the addi-
C1232 shall apply in this guide.
tional material listed in Appendix X1 in this standard, and
other publications.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 cryptoflorescence, n—a crystalline deposit of water-
5. Principles of Efflorescence
soluble compounds in the pores of unit pavement system
materials.
5.1 Efflorescence is directly related to the quantity of
water-soluble compounds within, or exposed to, a unit pave-
ment system; and to the quantity of water exposed to these
compounds. Water-soluble compounds or water causing efflo-
This test method is under the jurisdiction of ASTM Committee C15 on
Manufactured Masonry Units and is the direct responsibility of Subcommittee
rescence may be from adjacent surfaces or beneath the pave-
C15.05 on Masonry Assemblies.
ment system: for example, fertilizer in runoff from adjacent
Current edition approved June 1, 2021. Published June 2021. Originally
flower beds or lawns; ground water evaporating through the
approved in 2014. Last previous edition approved in 2016 as C1791–16. DOI:
10.1520/C1791-16R21. wearing course; water-soluble compounds leaching out of
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1791 − 16 (2021)
crushed recycled concrete used in pavement bases; and water mortar joints; cold weather construction practices that prevent
from sprinkler systems and roofs. Since neither water nor masonry materials from freezing.
water-soluble compounds can be completely eliminated from 6.2.3 Construction practices that protect uncompleted unit
unit pavement systems, the potential for efflorescence is pavement systems from rain or snow during construction.
reduced by reducing water-soluble compounds and water
6.2.4 Properly sized and located movement joints in the
retained within the unit pavement system. pavement and in rigid bases such as concrete.
6.2.5 Gutters, overhangs, and canopies to protect the pave-
5.2 Water can penetrate through joints in the surface of unit
ment from rain.
pavementsystems.Itcanpenetratevoidsinthemortarjointsor
6.2.6 For concrete paving units, utilization of integral efflo-
the interface between the paver unit and jointing material.
rescence controlling compounds in the units or compatible
5.3 If a significant amount of water penetrates a unit
applied water repellent sealer on the surface of unit pavement,
pavement system, the water will dissolve water-soluble com-
or both.
pounds that may exist in the paver units, mortar components,
6.2.7 Utilization of compatible integral water repellent ad-
grout,settingbed,concreteslab,admixturesorothersecondary
mixtures and mortar modifiers.
sources, and may deposit them on the exterior surface of the
6.3 Water that penetrates a unit pavement system is quickly
unit pavement system when it migrates to the surface and
drained out of the system by:
through evaporation. The presence of a concrete slab below
6.3.1 The use of a drainage system that conveys water to
sand setting beds in unit pavement system allows water to
low points and allows water to be conveyed out of the
remain on top of the slab where it can more readily dissolve
pavement system.
water-soluble compounds in the concrete.
6.3.2 Drainage holes through the slab base at the low points
5.4 The most common efflorescence deposits contain two or
in systems that are installed over slab bases to drain water off
more of the following: potassium, sodium, calcium, sulfates,
the slab base.
carbonates, bicarbonates, chlorides, and hydroxides.
6.4 Contact between dissimilar paver units is minimized by:
5.5 Some water-soluble compounds deposited on the sur-
6.4.1 The use of a separator between changes in paver
face of unit pavement systems can chemically react to form
materials in unit pavement systems.
compounds
...