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NBSIR 84-2919
REVIEW OF TEST METHODS, PERFORMANCE REQUIREMENTS AND MATERIALS FOR
CONSOLIDATING DEGRADED MASONRY SURFACES
Mary E. McKnight
Building Materials DivisionCenter for Building TechnologyNational Engineering LaboratoryNational Bureau of StandardsWashington, DC 20234
Prepared for:
United States Air Force Engineering Services Center
Tyndall Air Force Base, FL
Contract No.
October 1984
U. S. Department of Commerce
National Bureau of Standards
#
NBSIR 84-2919
REVIEW OF TEST METHODS, PERFORMANCE REQUIREMENTS AND MATERIALS FORCONSOLIDATING DEGRADED MASONRY SURFAGES
Mary E. McKnight
Building Materials DivisionCenter for Building TechnologyNational Engineering LaboratoryNational Bureau of StandardsWashington, DC 20234
Prepared for:
United States Air Force Engineering Services CenterTyndall Air Force Base
,FL
Contract No.
October 1984
U, S. DEPARTMENT OF COMMERCE, Malcolm Balrige, SecretaryNATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
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TABLE OF CONTENTS
PAGE
ABSTRACT v
1. INTRODUCTION 1
2. PERFORMANCE 2
2.1 Consolidating Ability 2
2.2 Depth of Penetration 3
2.3 Water Vapor Permeability 3
2.4 Compatibility 4
2.4.1 Thermal 4
2.4.2 Chemical 4
2.5 Change in Appearance 4
2.6 Coatability 5
2.7 Durability 5
3. CONSOLIDATING MATERIALS 7
3.1 Inorganic Materials 7
3.2 Alkoxysilanes 7
3.3 Organic Materials 8
4. PERFORMANCE REQUIREMENTS 10
4.1 Consolidating Ability 10
4.2 Depth of Penetration 10
4.3 Water Vapor Permeability 11
4.4 Compatibility 11
4.4.1 Thermal 11
4.4.2 Chemical 11
4.5 Change in Appearance 11
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TABLE OF CONTENTS
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4.6 Coatablllty 12
4.7 Durability 12
5. RECOMMENDATIONS 14
6. REFERENCES 15
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ABSTRACT
When a masonry surface with a weakened, deteriorated surface layer is to be
coated, special preparation of the surface prior to maintenance coating is
required. Two methods of surface preparation are usually used: 1) removal
of the deteriorated surface layer and 2) consolidation of the deteriorated
layer. Although the recommended procedure is to remove the degraded surface
material, this procedure is not always possible. This report is concerned
with the second approach, i.e., consolidation of the deteriorated surface
layer. The literature was reviewed for test methods used to assess the
performance of consolidating materials, the types of materials used, and the
performance requirements needed for consolidating materials. Current test
methods in use for evaluating consolidating ability, depth of penetration, water
vapor permeability, thermal and chemical compatibility, appearance, recoatability
and durability are described. Performance requirements found in the literature
for these properties are cited. Consolidating materials fall into one of
three classes: 1) inorganic materials, 2) alkoxysilanes,and 3) organic materials.
However, none of these materials has been found to completely meet all the
performance requirements sited. Recommendations for further work include
characterization of mechanisms of degradation and developing improved accelerated
tests and performance criteria.
Keywords: Consolidating materials; masonry; performance criteria; test
methods
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1 . INTRODUCTION
Weathering of masonry surfaces, improper cleaning procedures, chemical
attack and use of inappropriate coating systems can result in a deteriorated,
weakened surface and loss of material [1,2]. When a weakened masonry surface
is to be coated, special preparation is required because application of most
coatings directly to a deteriorated surface may lead to failure. Two approaches
for the preparation of a deteriorated surface are 1) removal of the deteriorated
layer and 2) consolidation of this layer. Although the former approach is the
preferred method according to the American Concrete Institute [3], it is not
always feasible to blast or otherwise remove the degraded surface layer.
Hence, consolidation of the surface may be desired. This report addresses
the second approach. The objectives of this report are 1) to review test
methods used for evaluation of consolidating materials, 2) to review generic
types of materials which are presently used as consolldants , 3) to review
reported performance requirements of consolidating materials, and 4) to recommend
research needed to improve the selection and specification of consolidating
materials
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2. PERFORMANCE TEST METHODS
Two ASTM standard practices [4,5] list recommended evaluation procedures
for exterior coatings. However, it is implicitly implied in the practices
that coatings will be applied to a sound, well-prepared surface. When the
substrate is weakened or deteriorated, additional evaluation procedures are
required. Many papers have been published on stone consolidants [6,7] and
several international symposia dedicated to this subject have been held [8,9].
This large bank of information is also pertinent to the problem of maintaining
other masonry surfaces. Included in the literature are details of performance
tests which have been used to evaluate stone consolidating materials [6].
These tests relate to 1) consolidating ability, 2) penetration, 3) permeability
of water vapor, 4) compatibility with the substrate and, 5) change in appearance.
These test methods can also be used for assessing consolidants for other masonry
materials. When the consolidating material is part of a coating system, com-
patibilty of intermediate or topcoat with the consolidated substrate also must
be determined. These special test methods, as well as more detailed procedures
for durability tests than described in the practices [4,5], are discussed
below.
2,1 Consolidating Ability
Since the primary function of a consolidating material is to bond together
the weak surface material of the substrate, a test which measures this ability
is required. In one such test, granules of crushed material, similar to that
of the substrate to be coated, which pass through a No, 30 (0,53 mm) but are
retained on a No. 50 (0.29 mm) seive ,are used to make test specimens [10],
The granules are throughly mixed with enough consolidating material to make a
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mold as described in ASTM C190 [11] and allowed to cure according to the directions
of the manufacturer of the consolidant. Tensile strength of the specimens are
measured
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2.2 Depth of Penetration
In order for the consolidating materials to bind weakened surface material
together, the consolidant must penetrate through the weakened layer to sound
substrate material. One test method developed to determine the depth of pene-
tration [9] uses a 150 mm cube of substrate material to which a a 140 mm diameter
glass cylinder is attached. All the exposed surface of the cube, except the
side opposite the cylinder, is coated with molten wax and allowed to cool, A
500 ml aliquot of consolidant is added to the cylinder and the assembly is
allowed to stand for one hour. The cylinder is then emptied and covered and
the consolidating material allowed to migrate for 24 hours. The specimen is
then fractured by knife edges along the plane parallel to the direction of
consolidant flow in a compression machine. Maximum depth of penetration of
the consolidant is measured. In another test, the consolidating material is
applied at the rate recommended for maintenance, the test specimen is fractured
and the depth of penetration is measured [12],
2.3 Water Vapor Permeability
Large changes in the water vapor permeability of masonry substrates caused
by the application of coatings are reported to be associated with accelerated
degradation [6], Changes in the permeability of consolidated materials, as
compared with untreated materials, can be determined using the method described
in ASTM E96 [13], Samples are sealed above either a 0 percent or 100 percent
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relative humidity environment and placed in a constant 50 percent relative
humidity environment at a specified temperature. The amount of water taken up
or lost is determined as a function of time.
2.4 Compatibility
2.4.1 Thermal
In this test procedure, thermal expansions of specimens of substrate
treated with the consolidant are compared with thermal expansion of untreated
specimens. A method to measure thermal expansion of consolidated stone using
an interferometer is available [14]. Specimens are dried at 105 C to constant
weight and then completely immersed in the consolidant for 4 hours. Viscous
materials are diluted with an appropriate solvent to increase their ability to
penetrate the specimens. Treated specimens are broken and the cross section
examined to be certain that the consolidants have penetrated to the center of
the specimens.
2.4.2 Chemical
Since most masonry substrates are alkaline, consolidating materials must
be alkali resistant. ASTM D1308 [15] describes a spot test procedure to
evaluate chemical resistance. Sodium hydroxide solutions having concentrations
by weight of about 0.5 percent are often used to evaluate alkali resistance of
coatings [16,17]. Since the laboratory test may not correlate with field
exposure durability, field tests are also performed.
2.5 Change in Appearance
When the consolidated surface is not to be topcoated, changes in color,
gloss and reflectance of the consolidated surface are important. To determine
4
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these changes, color [18], reflectance [19] and gloss [20] of untreated substrate
material are measured. The substrate is coated with the consolidant and the
consolidant allowed to cure. Color, reflectance and gloss of the consolidated
material are measured and the values compared with those obtained before coating.
Changes in texture between untreated and treated masonry surfaces can also be
important even if a topcoat is applied. No standard methods are available to
assess change in texture. Evaluation of texture should include such properties
as smoothness and porosity,
2.6 Coatability
When a consolidant is used as part of a coating system, it is essential
that good interfacial adhesion be obtained and that it remain so after weathering.
Adhesion of a coating applied to a consolidated surface can be measured quali-
tatively using a tape test according to ASTM method D3359 [21] and after immer-
sion in distilled water (Fed. St. Test Method 141, Method 6301 [22]). To
obtain more quantitative numbers, tensile adhesion can be measured using a
pneumatic adhesion tester [23],
2.7 Durability
Although there is guidance on evaluation of performance of coatings in
durability tests in the ASTM Standard Practices [4,5], additional information
is needed to completely specify the testing procedure. Evaluation of consolidated
specimens (complete with the topcoats, if any) in accelerated laboratory tests
should be accompanied with exterior field testing. Laboratory tests should
include 1) exposure in an accelerated weathering machine with moisture and 2)
exposure to freeze-thaw cycles. Acid rain tests should also be conducted if
the structure will be exposed to acid rain conditions. An acid rain test.
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used in evaluation of consolidating materials, has been described [10]. In
this test, specimens are exposed to water, acidified with C02, NOx,or S02
,
which drip on the surface of the treated substrate. The amount of material
that is dissolved is measured. Field tests should be carried out in several
different climate zones. Changes in appearance, adhesion and water vapor
transmission, as a result of either field or laboratory testing should be
determined as described in sections 2.3, 2.5 and 2.6.
6
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3. CONSOLIDATING MATERIALS
Several types of materials have been used as consolidants . These materials
can be classified into one of the following types: inorganic, aloxysilanes
,
and organic polymers.
3.1 Inorganic Materials
Inorganic materials, such as calcium hydroxide and barium sulfate, were
used extensively during the 19th century as stone consolidants and are still
being used occasionally [6]. However, in general, these materials have not
been very successful in consolidating stone and some acceleration of stone
decay as a result of their use has been noted [6]. This accelerated deteriora-
tion is thought to be due to a hard crust that develops on the surface and to
changes in molecular structure that occur as a result of their use. Soluble
alkali silicates have also been used for consolidation of stone but poor perfor-
mance has often been reported [6]. However, soluble alkali silicates are now
being considered for consolidation of degraded concrete or stucco.
3.2 Alkoxysilanes
Alkoxysilanes are reported to be good candidates for stone consolidating
materials because of their ability to penetrate the surface effectively before
polymerizing and because the film formed has little effect on the flow of
water vapor, on the frost resistance of the stone, and on the porosity of
stone [28], In experimental studies, silane consolidants were found to effect-
ively penetrate test specimens [12,24]. However, in one study, two alkoxysilanes
failed to form moldable specimens in the consolidation test described in section
2.1 [10]. Alkoxysilanes which are applied in the polymerized state are often
called silicones and their use as water-repellents is well known [25,26].
7
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3.3 Organic Materials
Two types of organic materials have been used to consolidate stone. In
one type, the monomer or an oligomer is applied directly to the surface and
polymerization takes place after application. In the other, the monomer is
polymerized before application. Methylmethacrylate monomer has been used to
consolidate several masonry materials and, where effective penetration was
achieved, the durability and mechanical properties of concrete were shown to
be improved [29]. Moldable specimens of limestone and sandstone were also
reported to be formed using a methylmethacrylate consolidant [10]. However,
incomplete impregnation may result in the formation of a distinct, undesirable
interface between treated and untreated material. Experiments are on-going to
determine the durability of treated brick in a mild coastal environment [24].
Pol 3nBeric materials which have been used as consolidants include acrylics,
vinyls, silicones, epoxies and urethanes. These materials are known for their
ability to form protective continuous films and are used to protect steel,
wood and the like. But for consolidation of masonry materials, the mechanism
of film formation for organic materials should be such that resinous material
is not deposited on the surface as the solvent evaporates. For if the polymer
is deposited on the surface, a distinct layer will be produced. Such a layer
may be quite resistant to the flow of water, and possess different thermal and
water absorption properties than the bulk substrate. This could cause excessive
shear stresses near the surface, resulting in spalling of the substrate [28].
In one study [10], two epoxy consolidants penetrated a sandstone specimen 2 to
3 mm and, in another study [7], an acrylic epoxy was found to reduce the permea-
bility of water vapor by 30 percent. However, the ability of epoxy consolidants to
consolidate ground stone has been demonstrated. The consolidated stone was
8
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resistant to erosion in the acid rain test (sec 2.7) [10]. An acrylic resin
was found to penetrate sandstone to a depth of about 15 mm, consolidate ground
stone and provide effective protection in the acid rain test [10]. Thermal
expansion of stone consolidated with organic polymers was found to be quite
variable [10]. For example, the coefficient of thermal expansion for sandstone
treated with an epoxy decreased by 15 percent; while for limestone treated with a
silane, the coefficient of thermal expansion increased by A3 percent as compared
with untreated material.
9
4
4. PERFORMANCE REQUIREMENTS
The performance requirements of consolidating materials that are related
to the tests described in section 2 are reviewed in this section. Other require-
ments relating to such characteristics as application properties and storage
stability are not included. These types of requirements are well established
and are found in most Federal paint specifications.
4.1 Consolidating Ability
The primary function of consolidating materials is to reinforce a weak
surface and protect it from further degradation. One means of assessing con-
solidating ability is to measure both tensile and compressive strength of the
consolidated surface material. A proposed performance requirement is that the
strength of the consolidated surface material, when prepared as described in
section 2.1, be similar to, but less than, that of the bulk material of the
substrate [6]. No numerical values defining "similar" were found in the liter-
ature .
4.2 Depth of Penetration
The ability of a consolidant to penetrate the surface depends upon the
porosity of the surface to be consolidated, as well as the physical and chemical
properties of both the substrate and the consolidating material. A high degree
of penetration may result in gradual changes taking place in the thermal and
chemical properties from the consolidated surface to the bulk material [20].
Penetration of a weathered porous surface to a depth of at least 25 mm has
been suggested as a performance requirement [31].
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4.3 Water Vapor Permeability
Consolidating materials are usually designed to restrict the flow of
liquid water but to allow the flow of water vapor. However, if water vapor
transmission is greatly retarded, moisture may accumulate behind the consolidated
surface. Then as water vapor slowly passes through the consolidated layer,
soluble salts will be carried toward the surface. Resulting crystal formation
could lead to spalling of the substrate or blistering of coating films or
both. It has been suggested that vapor transmission of a consolidated surface
should be no less than 50 percent of an untreated surface [7].
4.4 Compatibility
4.4.1 Thermal
To minimize shear stresses, the coefficient of thermal expansion of the
consolidated layer should be similar to that of the bulk substrate. Recommended
performance requirements for thermal properties were not found in the literature.
4.4.2 Chemical
Chemical compatibility of the consolidant with the substrate is required
for good durability. No data relating performance in accelerated chemical
exposure tests to in-service performance were found. Minimum suggested perfor-
mance requirements for in-service tests should require no deterioration after
several years exposure in moist, warm climates.
4.5 Change in Appearance
The effect of consolidating materials on the appearance of masonry substrates
has been reported to include changes in color and reflectance, formation of a
white substance in the pores and a smoothing of the overall appearance [6].
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The importance of these effects on the overall appearance of the material is
best left to the decision of the maintenance engineer. Changes in color of 1
to 2 Hunter color units [18] are usually apparent visually. Changes in reflect-
ance, gloss and texture may also be undesirable. Changes in reflectance of
less than 10 percent [19] and of 85 degree gloss of less than 10 percent [20]
are normally not detected visually. Since there are no visual standards for
characterizing texture, only qualitative requirements can be specified at
present
.
4.6 Coatability
When a consolidating material is being used as part of a coating system,
the intermediate or topcoat must be compatible with the consolidated surface.
Both initial adhesion of the intermediate or topcoat to the consolidated surface
and adhesion after weathering must be adequate. Initial values of tensile
adhesion of an acrylic latex to untreated concrete surfaces have been reported
to range from 1 to 5 MPa depending on the method of casting and the surface
pretreatment [32]. An estimate of acceptable adhesion of 0.8 MPa for architect-
ural paints and 1.2 MPa for floor paints has been reported [32]. When qualita-
tive tests are used, such as a tape test, there should be no intercoat adhesion
failure observed.
4.7 Durability
For any environment, the durability of the consolidated surface will depend
on both the durability of the consolidating material and the consolidated
surface. As for other coatings, durability of the consolidating materials
will depend on their resistance to degradation by ultraviolet radiation, temper-
ature cycling, moisture and pollutants. Many factors will affect the durability
12
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of the consolidated surface Itself, These include depth of penetration of the
consolidant, compatibility of the consolidating material with the substrate and
porosity. Pore size and pore size distribution have been reported to have an
effect on the durability of the surface [30], (Frost and salt crystallization
damage increase as the proportion of small pores and cracks increases. Thus,
partially filling pores and cracks with consolidating materials could be harmful,)
Exposures of 1000 hours in an accelerated weathering machine, of 1000
hours in the acid rain environment, or of 1000 cycles in the freeze-thaw test
or of a combination of the tests have been reported [7,10], Suggested interim
performance requirements for coating systems are that color changes as a results
of such exposures be less than 1 liinter unit and that no loss of surface integrity
be observed. But, because of the often observed poor correlation of accelerated
durability tests with field tests, field testing of materials should also be
carried out.
13
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5. RECOMMENDATIONS
From this study, it is obvious that there is a need for further evaluation
of consolidating materials in both the laboratory and the field. There is
very little assessible data on the service life of consolidating materials and
little comparable laboratory data. Standard test methods are not available to
measure many of the key performance properties. Work to relate some laboratory
measured properties with service life is just beginning; hence, only a few
performance criteria have been established. Therefore, the following recommen-
dations for further work are made;
Initiate field tests of consolidating materials from each generic class
over degraded concrete, stucco or other masonry surfaces. Test specimens
should include both those topcoated and not topcoated.
Perform the laboratory tests described in section 2 on materials exposed
in field tests to develop new or improved performance criteria.
Characterize the mechanisms of degradation observed in both the field
and laboratory tests.
Using the information obtained in the mechanistic research, develop new
test methods, as needed, to characterize the performance properties of
candidate materials.
Work to develop voluntary consensus standards so that performance data
can be compared more easily among laboratories. This would improve the
knowledge base so that coating selections could be made more effectively.
14
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6 REFERENCES
1. Johnson, Sidney, M,, Deterioration, Maintenance, and Repair of Structures,
McCraw Hill, New York, New York, 1965.
2. Grimmer, Anne E.,"Masonry Conservation: Documentating Condition and
Treatment of Historic Building Materials," Technology and Conservation,
6, No. 2, 32(1981).
3. "A Guide to the Use of Waterproofing, Dampproofing, Protection and DecorativeBarrier Systems for Concrete," ACI 515R-1, Concrete Abstracts, 8, No.l,515R-1 ,(1980)
.
4. ASTM D3129, "Standard Practice for Testing Exterior Latex House Paints,"Annual Book of ASTM Standards, Part 06.01, American Society for Testingand Materials, 1916 Race Street, Philadelphia, PA 19103.
5. ASTM D2932, "Standard Practice for Testing Experior Solvent-Based Houseand Trim Coatings," Annual Book of ASTM Standards, Part 06.01, AmericanSociety for Testing and Materials, 1916 Race Street, Philadelphia, PA19103.
6. Clifton, J. R. , Stone Consolidating Materials—A Status Report, NBSTN-1118,National Bureau of Standards, Washington, D. C., 1980.
7. Sleater, G. A., A Review of Natural Stone Preservation, NBSIR 74-444,
National Bureau of Standards, Washington, D.C.,1973.
8. The Conservation of Stone I, Proceedings of the International Symposium,Bologna, June 1975 (Centro per la Conservazione deele Sculture all’Aperto,Bologna, Italy, 1976).
9. Conservation of New Stone and Wooden Objects, New York Conference, June
1970 (The International Institute for Conservation of Historic and Artistic
Works, London).
10. Clifton, J. R. and Godette, M., "Performance Tests For Stone Consolidants,
"
to be published as an NBSIR.
11. ASTM C190, "Test for Tensile Strength of Hydraulic Cement Mortars," Part
13, 1982 Annual Book of Standards, 1916 Race St., Philadelphia, PA 19103.
12. DeWitte, E.,Florquin, S., and Terfve, A., "The Efficiency of Water Repel-
lents for Historic Buildings," Material Science and Restoration, Technische
Akademie Esslingen, International Colloquim, Sept, 1983, p. 131.
13. ASTM E96, "Tests for Water Vapor Transmission in Materials," Part 27,
1982 Annual Book of Standards, 1916 Race St., Philadelphia, PA 19103.
15
--t. „
- —I—,, I, ,p
m .1;^'.‘4’
(: -UWA'fTWWljfcTD Jt
•*v ,' i a rcn^^att itrn^'
id- ,»»<J''‘<|/f3;: oi A"; ,,^/
“ • ijk,f ^
"W
irc'i/i^/ft ,j(J-
..-!PIBilP6- 3d#.?h=:«g|r ,^=C ^:: -..I*;?.;,
. ai
S:2
-«*. ©
'
,
'
E?*
'"
JB* -rt-.
' iP"-' -. isffl' '\-^
r-:5s
.:‘!i
-„ - ._...*-trtobito4 ";*,
„ ..^
->.,. -- ,- ,,. 4..., ... ---. ...... . .,.- ^--:^~.-|p
"ii ‘-
• ''"(: ^IjQ .'„ «^,,, M'-:f-''*
’'
^' —
'-
‘
KfaEf Iff., - '• ?.-' ' ^•
r ,X''i'J
i>
. .v;:s»ilLl Si
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14. ASTM E269, "Test for Linear Thermal Expansion of Rigid Solids with Inter-ferometry," ASTM E289, Part 41, 1982 Annual Book of Standards, 1916 RaceSt., Philadelphia, PA 19103.
15. ASTM D1308, "Standard Test Method for Effect of Household Chemical on Clearand Pigmented Finishes," Annual Book of ASTM Standards, Part 06.01, AmericanSociety for Testing and Materials, 1916 Race Street, Philadelphia, PA19103.
16. Federal Paint Specification, TT-P-29j,"Paint, Latex Base, Interior,
Flat, White and Tints," Copy can be obtained from Naval Publications and FormsCenter, 5801 Tabor Avenue, Philadelphia, PA 19120.
17. Federal Paint Specification, TT-P-1511b, "Latex (Gloss and Semigloss, Tintsand White, for Interior Use," Copy can be obtained from Naval Publicationsand Forms Center, 5801 Tabor Avenue, Philadelphia, PA 19120.
18. ASTM D2244, "Instrumental Evaluation of Color Difference of Opaque Materials,"Annual Book of ASTM Standards, Part 06.01, American Society for Testingand Materials, 1916 Race Street, Philadelphia, PA 19103.
19. ASTM E97, "Tests for 45-deg, 0-deg Directional Reflectance Factor of OpaqueSpecimens by Broad Band Filter Reflectometry ," Annual Book of ASTM Standards,Part 06.01, American Society for Testing and Materials, 1916 Race Street,Philadelphia, PA 19103.
20. ASTM D523, "Standard Test for Specular Gloss," Annual Book of ASTM Standards,Part 06.01, American Society for Testing and Materials, 1916 Race Street,Philadelphia, PA 19103. Book of ASTM Standards, Philadelphia, PA.
21. ASTM D3359, "Standard Test Method for Measurement of Adhesion by TapeTest," Annual Book of ASTM Standards, Part 06.01, American Society for
Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.
22. "Wet Adhesion," Fed. Test Method Std. No. 141B, Method 6301, U.S. PrintingOffice
.
23. Seiler, J. F,,McKnight, M. E.
,and Masters, L. W., "Development of A Test
Apparatus and Method for Measuring Adhesion of Protective Coatings,"NBSIR 82-2535, National Bureau of Standards, Washington, D. C., 1982.
24. Taylor, T. H,,"Conservation of Original Brickwork at Colonial Williamsburg,"
Material Science and Restoration, Technlsche Akademie Esslingen, Inter-
national Colloquim, Sept, 1983, p. 385.
25. Water-Repellant Coatings, CSI Monograph, 07M175, Construction Specification
Institute, Washington, D, C., 1974.
26. "Dampproofing and Waterproofing Masonry Walls," Technical Note on Brick
Construction No. 7, 76.01 Brick Institute of America, McLean, VA, 1961.
16
r-'
„ ..f'•
Ti* ^j|rr^4; •»Li^ 'n' ii^iB i.*vi "]>£«p’an^4ii
.,. ,,
-I -At rf«n ''*cil
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•'"-?^, AH AlAisU6Al 4iW >
L ..1
, j .. fr. «?». -fcriwD . tl'
ftrtiift *’, aOe '<
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v,
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- ,\fl'' -A'
'' '/'"* A '. ‘ IB
,'"• \i ’ -“^''jiVt'',W;
MTSA %Q ^^bSsX^ti> A
‘
'
.g;, 'IbAAit tif '©^oei'^'^a
^ _fer'
. tSD’lH 35»A^ , co*Ao ' ^i <o ife -S^Av 1 , , B$C€0_^8A'"
^ # i ^-
^ -% \.' ' .-JA ./. il/ <- .''I.vi ‘L -' E. :ju <M .'tA ’ ‘)Grini^ .ALi. tlil'i^: ^trXmk.t^' i* te'r«i..«M II ^ 4 A' /^
MW!;.
1V> ‘fikt^ri^ 3l{^; l»uu«A *',»ia»T
s^ %., ,
*>nA ^’iis»T
1
-1 -,
- -.r,'Tv '/:i''V .,'4V '^W **'^'^,
,
’^'''
jjtii'lnli^ . i<^ ,34;A|. ^*’,iiJOiB*d
•iia ,',
i W!3^:i»TX9Vim>\/- 4 .»m *•» »
mk
r
‘'T,
M "', :'j
3 (lAll -aqa^f-^lwaaV ' f
' ,mti-!(M9»V/ ,jtyp^lSkaX '^•^: f • '9.
jA ^
27. Kukacka, L, E. ,Auskern, A., Colombo, P.
,Fontana, J., and Steinberg, M.,
"Introduclotn to Concrete-Polymer Materials, Brookhaven National Laboratory;Available from National Technical Information Service, No. PB 241-691.
28. Furlan, V. and Panalla, R., "Effects of Water on Properties of a CalcareousSandstone Consolidated with Synthetic Resins, Material Science and Restora-tion, Technische Akademie Esslingen, International Colloqulm, Sept, 1983,
p. 335.
29. Hranilovic, M. and Ukraincik, V., "Adherence of Polymer Cement Mortarto Concrete," Material Science and Restoration, Technische Akademie Esslingen,International Colloquim, Sept, 1983, p. 249.
30. Decay and Conservation of Stone Masonry, Digest 177, Building ResearchStation (Garston, England, 1975).
31. Price, C. A., Stone Decay and Preservation, Chemistry in Britain, 11, No.
9, 350 (1975).
32. Lindberg, B., "Painting Concrete", J. of Oil Col. Chem. Assoc., 57, 100(1974).
17
