January 1985
PROPERTY J
• DIVISICs
OF
EFFECTS OF ACZD DEPOSITION 08 THE PROPERTIES
OF PORTLAND CEMENT CONCRETE
STATE-OF-KNOVLEDGE
ATMOSPHERIC SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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EFFECTS OF ACID DEPOSITION ON THE PROPERTIES
OF PORTLAND CEMENT CONCRETE
STATE-OF-KNOWLEDGE
R. P. Webster and L. E. Kukacka
Brookhaven National Laboratory
Upton, NY 11973
DW899307010-01-0
Project Officer
John W. Spence
Emissions Measurement an.d Characterization Division
Atmospheric Sciences Research Laboratory
Research Triangle Park, NC 27711
ATMOSPHERIC SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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NOTICE
The information in this document has been funded wholly
by the United States Environmental Protection Agency under
Interagency Agreement DW899307010-01-0 to Brookhaven National
Laboratory. It has been subject to the Agency's peer and
administrative review, and it has been approved for publica-
tion as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for
use.
ii ,
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ABSTRACT
Presented are the results of a program conducted to
determine the state-of-the-art knowledge pertaining to the
effects of acid deposition on the properties of portland cement
concrete structures. Information was collected from a comput-
erized literature survey, interviews, and replies to mail and
telephone inquiries addressed to cement and concrete research-
ers and to governmental agencies and private firms active in
the maintenance and restoration of concrete structures. In
general, the study revealed very little qualitative or quanti-
tative information on the effects of acid deposition on PCC
structures. The rate of deterioration of reinforced PCC struc-
tures in polluted areas, however, appears to be increasing, and
available information makes it readily apparent that acids and
acid waters significantly affect the durability of concrete,
and that SC>2» NOX> and HC1 accelerate the corrosion of
reinforcing steel.
iii
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CONTENTS
Abstract ill
Abbreviations and Symbols vi
1. Introduction 1
Background I
Program Objectives 1
Program Summary 2
2. Conclusions and Recommendations ..... 6
3. State-of-the-Art Review 8
Background ..... 8
Literature Survey. ........ 8
a. General Summary 8
b. Resistance of Concrete to Chemical Attack . . 11
Effects of Acids 11
Effects of Carbon Dioxide 15
Effects of Sulfur Dioxide 17
Effects of Nitrogen Oxides 20
Mail and Telephone Inquiries 20
Summary 22
References 24
Appendices 29
A. Summaries of Selected References 29
B. Individuals and Organizations Surveyed 35
C. Letter of Inquiry 37
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LIST OF ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS
PCC
SYMBOLS
C3A
CaC03
Ca(OH)2
CaS04
C1,C1-
G02
H2S03
H2S04
HC1
HN02
HN03
NH3
N03,N03~
NOX
S02
S03 ,S03-2
S04,S04-2
sox
Portland cement concrete
tricalcium aluminate
calcium carbonate
calcium hydroxide, i.e. lime
calcium sulfate, i.e. gypsum
chlorine, or chloride
carbon dioxide
sulfurous acid
sulfuric acid
hydrochloric acid
nitrous acid
nitric acid
ammonia
nitrate
nitrogen oxides
sulfur dioxide
sulfi te
sulfate
sulfur oxides
vi
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SECTION 1
INTRODUCTION
BACKGROUND
Over the last 25 years, an increasing amount of evidence
has been gathered indicating that acid deposition, resulting
from the emission of oxides of sulfur and nitrogen into the
atmosphere, has a significantly adverse effect upon man's en-
vironment including the acidification of lakes, rivers and
groundwaters, acidification and demineralization of soils, re-
duction of forest productivity, damage to crops, and deterio-
ration of building materials.(*"'' Although much of this
evidence pertains to the effects of acid deposition on the
natural environment, i.e. lakes, rivers, forests and crops, it
is becoming increasingly clear that acid deposition has a sig-
nificant impact also on the durability of building materials
such as metals, masonry, bui.lding stone, and concrete. Since
concrete is the most widely used construction material in the
United States, any comprehensive assessment of the economic
impact of acid deposition on materials should include consider-
ation of portland cement concrete (PCC) and steel reinforced
PCC. To this end, Brookhaven National Laboratory (BNL) has
carried out a program as part of the National Acid Precipita-
tion Assessment Program (NAPAP) Task Force Project G3-1.05,
sponsored by the Environmental Protection Agency/Atmospheric
Sciences Research Laboratory (EPA/ASRL), entitled "Effects of
Acid Deposition on the Properties of Reinforced Portland Cement
Concrete Structures."
PROGRAM OBJECTIVES
The specific objectives of the BNL program were (a) to
determine the state-of-the-art-knowledge pertaining to the
effects of acid deposition on the properties of portland
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cement concrete (FCC), and (b) if the results indicated a need
for quantitative data, to develop recommendations for an exper-
imental test program to be submitted for Task Group G approval
and implementation.
PROGRAM SUMMARY
This report presents a summary of the state-of-knowledge
pertaining to the effects of acid deposition on the properties
of portland cement concrete. Information for this review was
obtained from a computerized literature survey, interviews, and
replies to mail and telephone inquiries addressed to cement and
concrete researchers and to governmental agencies and private
firms active in the maintenance and restoration of concrete
structures.
In general, the computerized literature survey indicated
that an abundance of literature on acid precipitation is avail-
able, but most of it deals with the chemistry of acid precipi-
tation and its effects on the natural environment. Literature
dealing with the effects on buildings and building materials
does exist, however, very little of it deals with the effects
on cement or concrete. The information that was found
regarding the effects of acid deposition on buildings and
building materials, however, indicates that the increasing
acidity of precipitation enhances normal weathering and corro-
sion processes. In addition, private communications indicated
that a rapidly increasing number of reinforced concrete struc-
tures in cities are showing deterioration which the respondents
attributed to S02, NOX, and HC1.
Because the literature on the effects of acid deposition
on PCC is limited, the large amount of literature dealing with
the corrosive effects of acids, acid waters, and sulfates on
concrete was reviewed in an attempt to estimate the effects of
acid deposition on PCC.
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This review indicated that acid solutions generally attack
concrete in a combination of four ways: (a) by dissolving both
hydrated and unhydrated cement compounds present in the cement
paste, (b) by dissolving calcareous aggregates present in the
composite, (c) through physical stresses induced by sulfate and
nitrate salts crystallized within the pore structure, and (d)
by salt-induced corrosion of the reinforcing steel.
The first two forms of attack involve the same mechanism:
the leaching away of water-soluble salts formed by reaction of
the acid with the calcium compounds present in the cement paste
and aggregate. This is one of the major mechanisms of the
deterioration of many ancient statues, monuments, and buildings
made with calcareous building stone in and near industrialized
areas of Europe.
The latter two forms of attack involve the development of
stresses within the pores of the cement paste or aggregate
which eventually cause the concrete to crack or spall. These
stresses result from the crystallization of salts that have
accumulated beneath the surface of the concrete or from salt-
induced corrosion of the reinforcing steel.
In addition to the forms of deterioration identified
above, the cracking and spalling of concrete due to acid-
induced corrosion can also lead to and accelerate other forms
of deterioration, most notably freeze-thaw deterioration.
The literature review concentrated on the effects of three
specific pollutants; carbon dioxide, sulfur dioxide, and nitro-
gen oxides.
Carbon dioxide was found to affect concrete in two ways;
through carbonation of the concrete surface and carbonic acid
attack. The carbonation of the concrete surface results in a
decrease of the pH value of the cement paste which eventually
leads to the corrosion of the reinforcing steel near the
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surface. Carbonic acid attack primarily results in the leach-
ing of calcium hydroxide from the surface and interior of the
concrete.
Sulfur dioxide, when dry, has little or no effect on dry
concrete. It does, however, combine with water and oxygen to
form sulfurous and sulfuric acid, both of which will attack
concrete. Sulfuric acid attacks concrete (a) by converting
calcium carbonate to gypsum, which is subsequently leached
away, and (b) by reacting with calcium compounds to form salts
which crystallize, producing enormous stresses within the pores
of the cement paste which eventually lead to spalling and
cracking. The latter form of attack is commonly known as sul-
fate attack.
Very little information was available regarding the ef-
fects of nitrogen oxides on concrete. They do, however, react
with water or, as ammonia, with oxygen to form nitrous and
nitric acid. Nitric acid is not as strong as sulfuric acid,
however, it is destructive enough to bring about extensive
deterioration even in highly diluted solutions, primarily
through the transformation of calcium hydroxide into highly
soluble calcium nitrate.
None of the individuals and organizations responding to
the mail and telephone inquiries was aware of any documented
information dealing specifically with the effects of acid
deposition on PCC structures, or of any research that had been
or was being done in this area. Comments on the need for such
research work were varied: some respondents thought it was
needed because the large volume of concrete structures in the
United States could present a potentially large problem;
others thought the need for such research was open to question
because they considered other mechanisms of deterioration to
be more important.
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The study revealed very little qualitative or quantitative
information on the effects of acid deposition on PCC structures.
The rate of deterioration of reinforced PCC structures in pol-
luted areas, however, appears to be increasing, and available
information makes it readily apparent that acids and acid
waters significantly affect the durability of concrete, and
that S02» NOX, and HC1 accelerate the corrosion of reinforcing
s tee 1.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
The results of the literature survey, private discussions,
and the responses to mail and telephone inquiries have indica-
ted that very little qualitative or quantitative information is
available dealing specifically with the effects of acid deposi-
tion on PCC structures, but there is a considerable amount of
information available indicating that acids and acid waters
have a significant effect on the durability of concrete. This
effect may not be sudden or dramatic, but it is a cause for
concern.
It has been well documented that high levels of pollutants
(S02, N0x> etc«) have greatly accelerated the deterioration of
many of the ancient statues, monuments, and buildings made
using calcareous building stone in and near the industrialized
areas of Europe. Evidence is now beginning to indicate that
rapidly increasing numbers of reinforced concrete structures
are also showing increased rates of deterioration which are
attributed by some to be due to exposure to high levels of S02»
NOX, and HC1.
On the basis of this evidence, it is recommended that an
experimental test program, consisting of both laboratory and
field tests, be developed and implemented to quantitatively
measure the effects of acid deposition on PCC structures. It
is, however, recommended that a preliminary series of acceler-
ated laboratory tests be carried out before a full-scale field
evaluation program is instituted. The objectives of the labor-
atory test program should be to identify the magnitude of the
problem and to attempt to differentiate between the effects of
wet deposition, dry deposition, and normal weathering. Para-
meters to be studied in the test program should include:
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wet deposition - various simulated acid rain mixtures
to differentiate between the effects
of 804, ^03, and the normal background
components of rain.
- simulated acid rain mixtures of
varying pH values.
dry deposition - various levels of S(>2 and NOX.
- various relative humidities.
normal weathering - freeze-thaw cycles.
Test methods used in the evaluation should include; (a)
tests to evaluate changes in the physical and mechanical
properties of the specimens, (b) chemical analyses to determine
the depth and rate of penetration of the aggressive solutions,
and (c) tests to monitor and control the treatment solutions
and to analyze them for materials being leached from the test
specimens.
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SECTION 3
STATE-OF-THE-ART REVIEW
BACKGROUND
Information pertaining to the effects of acid deposition
on the properties of portland cement concrete was obtained (a)
from a computerized literature survey, and (b) from mail and
telephone inquiries, and meetings with cement and concrete
researchers, and from government agencies and private firms
active in the maintenance and restoration of concrete struc-
tures.
The information collected in these surveys was used to
determine: (a) if data exist regarding problems associated
with the effects of acid deposition on PCC, and what the econo-
mic impact of these problems may be, (b) if any research work
has been or is being done to investigate the effects associated
with acid deposition, and (c) if there is a need for experimen-
tal work to be done in this area. Results of each survey are
summarized below.
LITERATURE SURVEY
General Summary
In the computerized literature survey, ten data bases,
listed in Table 1, were searched for information on acids,
acid deposition, and portland cement concrete. A total of 132
papers and reports were collected and reviewed. In general,
this literature dealt with one of four subject areas; (a) the
chemistry of acid precipitation, (b) the effects of acid depo-
sition on the natural environment, (c) the effects of acid
deposition on buildings and building materials, and (d) the
effects of acids and acid waters on concrete. The survey
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Table 1. DATA BASES USED IN COMPUTERIZED LITERATURE SEARCH
Data Base
Supplier
Dates Covered
CA SEARCH
CAB ABSTRACTS
COMPENDEX
DOE ENERGY
ENVIROLINE
ENVIRONMENTAL
BIBLIOGRAPHY
NTIS
PAIS
INTERNATIONAL
POLLUTION
ABSTRACTS
SCISEARCH
Chemical Abstracts Service
Commonwealth Agricultural
Bureau
Engineering Info., Inc.
Office of Scientific and
Technical Information
(OSTI)
Environmental Info., Inc.
Environmental Studies Inst.
National Technical Info.
Service
Public Affairs Information
Service, Inc.
Cambridge Scientific
Abstracts
ISI Inc.
1980-81
1972-1983/Dec.
1970-1983/Aug.
1974-1984/Mar.
1970-1984/Mar.
1974-1983/Oct.
1964-1983/Iss25
1976-1984/Apr.
1970-1983/Dec.
1981-1984/Mar.
Keywords: acid rain, acid precipitation, acid deposition,
cement, portland cement, concrete, buildings,
structures, deterioration, building materials
revealed an abundance of literature on acid precipitation, but
most of it deals with the chemistry and effects on the natural
environment. Some of the papers include general statements
indicating that the increasing acidity of precipitation enhan-
ces the weathering and corrosion of materials and buildings,
but nothing any more speci f ic .
)
por example, Trumbule
and Tedeschl(12) state: "Acid rain also is believed to cause
damage to buildings and other manmade structures. One estimate
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places damage to structures in the eastern third of the United
States from acid rain at $2 billion per year in 1978 dollars."
They do not, however, cite any supporting data or damage
functions describing the deterioration. Martin'^) also makes
a similar statement.
The literature also indicates that while it is felt, by
some, that acid precipitation does have an adverse effect on
the performance of building materials, no work apparently is
being done to investigate these effects. Ashton and
Sereda^1^) report that: "Monitoring of the concentration of
pollutants in the atmosphere and in rain is done by various
government agencies in many countries, but little effort is
directed to the study of their effect on building materials,
particularly that of acidic components in rainwater."
Of the articles reviewed, ~20% dealt with the effects of
acid deposition on buildings and building materials, and most
of those dealt with its effects on natural building stones
(marble, limestone, sandstone) and metals (steel, iron, alumi-
num). (14-27) Only references 4, 5, and 23-27 dealt directly
with the effects of acid deposition on cement or concrete.
Each of these is summarized in Appendix A.
Because the literature on the effects of acid deposition
on PCC is limited, the large amount of literature dealing with
the corrosive effects of acids, acid waters, and sulfates on
concre te( 28-54) wag use
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Resistance of Concrete to Chemical Attack
Effects of Acids -
Since concrete, chemically, is a basic material, having a
pH of about 13, it is subject to attack by acids. Woods(37)
reports that concrete is not very resistant to strong solutions
of sulfuric, sulfurous, hydrochloric, nitric, hydrobromic, or
hydrofluoric acids, and is destroyed by prolonged contact with
any of these, though not necessarily at the same rate. Weaker
solutions (<1%) attack concrete at a slower rate, but in some
cases the severity of the attack can be very significant.
Woods further states that for all practical purposes, an acid-
ity of pH 5.5 to 6 may be considered the limit of tolerance of
high quality concrete in contact with any of these acids,
although the pH value is not invariably a good criterion of the
aggressiveness of acids. The chemical composition of the acid
is at least as important as pH in influencing the rate a.t which
concrete is attacked.
Galloway^1) reports that the relative contribution of
H2S04, HN03, and HC1 to the acidity of precipitation is
difficult to determine because the acids are not present as
such in solution but rather as dissociated ions. However,
using the absolute concentration of 804, NC>3 and Cl it is
possible to determine their relative contribution. Likens and
Bormann^2) and Glass et al^3) report that precipitation
data for the northeastern United States indicate that 60 to 70%
of the acidity in acid precipitation is due to sulfuric acid,
30 to 40% to nitric acid, and ~5% to hydrochloric acid. For
this reason, the following discussion of the effects of acids
on concrete will focus on effects of sulfuric acid.
In general, acid solutions attack concrete in any combi-
nation of four ways: (a) by dissolving both hydrated and
11
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unhydrated cement compounds, (b) by dissolving calcareous
aggregates present in the mix, (c) through physical stresses
induced by the deposition of soluble sulfate and nitrate salts
and the subsequent formation of new solid phases within the
pore structure, and (d) by salt-induced corrosion of the
reinforcing steel.
The first two forms of attack involve the same mechanism:
the leaching away of water-soluble salts formed by reaction of
the acid with the calcium compounds in the cement paste and
aggregate. When calcareous materials are attacked by sulfuric
acid, the sulfate radicals in the acid react with the calcium
carbonate (CaCOj) to produce calcium sulfate (CaSO^) , or
gypsum. Since gypsum is much more soluble in water than cal-
cium carbonate, it is readily washed away. This process even-
tually results in the complete destruction and removal of any
calcareous material exposed to attack. Brown(31)f reports
that this is the type of damage observed on the walls and floor
of the lock chamber of the Holt Lock and Dam near Tuscaloosa,
Alabama, after they were subjected to prolonged contact with
waters having a pH of about 4.2. The damage consisted of a
large number of areas where the limestone coarse aggregate was
removed from the surface of the concrete to depths of 0.64 to
1.27 cm (1/4 to 1/2 in.). The evidence, collected by the Corps
of Engineers, indicated that the removal of the aggregate was
due to the dissolution of the exposed aggregate particles by
acid or acids in the river water as pollution from local strip
mines. While the source of the acid may be different, this
type of deterioration has also been documented to be one of the
major mechanisms of the damage occurring to many of the ancient
statues, monuments, and buildings made with calcareous building
stone in and near industrialized areas of Europe.(4-6,14-17,
21-23)
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Acid attacks cement paste the sane way: it reacts with the
calcium compounds in the paste, such as calcium hydroxide and
calcium carbonate, producing soluble salts that are easily
leached away. Gradually, the acid also attacks the hydrated
minerals in the cement paste, again producing soluble salts.
The leaching process results in the gradual loss of cement
paste from the surface of the concrete and eventual exposure of
the aggregate. In addition, Tremper(30) reports that the
leaching process is not limited to the surface of the concrete,
but also extends into the concrete. He states that as calcium
carbonate is removed from the surface, calcium hydroxide (lime)
diffuses from the interior to the surface and is precipitated
as calcium carbonate. When calcium hydroxide is thus precipi-
tated, the water held in the pores of the concrete becomes un-
saturated and more calcium hydroxide is taken into solution.
There is thus a continuous travel of calcium hydroxide from the
interior to the surface, resulting in a general loss of lime
throughout the body of the concrete. In its early stages, this
form of attack is characterized by a slight etching of the sur-
face, and, in later stages by severe pitting and scaling,
followed by'a gradual decrease in strength.
The third form of attack is a secondary effect of the
first two forms. The reaction of acids with the various cal-
cium compounds present in the cement paste or aggregate leaves
a residue of soluble salts, which accumulates on or just
beneath the surface. The salts at the surface are leached away
by rainwater, the salts accumulated beneath the surface can
crystallize with the absorption of water, which increases their
volume. This results in the development of enormous stresses
within the pores of the cement paste or aggregate, which can
eventually lead to blistering and spalling of the surface. In
addition, some of the sulfates formed, such as gypsum, react
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with the hydra ted tricalcium aluminate in the cement paste to
produce ettringite (3CaO'A1203•3CaS04'31H20) , which also
occupies a large volume and, thus, can also cause cracking.
The accumulation of salts beneath the surface can also
lead to the formation of crusts in protected areas that are
shielded from washing by rainwater. These impermeable crusts
can hold water and salts within their pore structure, causing
the concrete or stone to spall off in layers rather than
gradually eroding.
Regarding this type of deterioration, Fishert4) reports:
"Many scientists think that acid deposition damages buildings
more through the physical stresses than through the chemical
reactions it brings on."
The accumulation of salts within the concrete pore struc-
ture can also lead to the corrosion of reinforcing steel, the
fourth form of deterioration identified above. This corrosion
is accompanied by an increase in the volume of the steel, which
eventually causes the concrete to crack and spall. In discuss-
ing the atomospheric corrosion of concrete reinforcements,
Skoulikidis(25) notes: "The increase of atmospheric pollution
intensifies the corrosion tendency of the reinforcements in the
atmosphere. The cracking of the concrete was observed more
frequently with an increase of the atmospheric pollution (SC>2,
C02» NH3 , NQX, etc.) and the acceleration of the corrosion by
the formation of a more conductive environment, that also
chemically attacks the metals."
In addition to the forms of attack already discussed,
cracking and spalling of concrete due to acid-induced corrosion
can also lead to and accelerate other forms of attack having
other causes, most notably freeze-thaw deterioration.
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found that concrete which normally withstood
attack due to freeze-thaw cycling was subject to attack after
exposure to acid solutions.
Effects of Carbon Dioxide -
Concrete is known to be affected by the take-up of C<>2
from ambient air, i.e. carbonation.<37»39-42) tfoods<37)
states: "The reaction between atmospheric carbon dioxide and
dense hardened concrete is very slow, and even after a consid-
erable number of years, may affect only a thin layer nearest
the exposed surfaces. A principal product of the reaction is
calcium carbonate, the presence of which may enhance the early
resistance of concrete to attack by some chemicals in solution,
such as sulfates. In practice, however, any beneficial effect
that may exist appears to be of relatively small moment."
The harmful effect of carbonation arises when the carbon-
ated layer created on the surface of reinforced concrete over
the years reaches the steel reinforcement. The alkaline pro-
tective layer is then considerably less alkaline, and the
steel bars may start to rust. Sentler'3?) has determined the
thickness of concrete cover required to protect the reinforcing
steel from corrosion as a function of the water/cement (w/c)
ratio. He finds that for a 50-yr life the concrete cover
needed for w/c » 0.4 or 0.8 is 12 or 45 mm (0.47 or 1.77 in.),
respectively, for a failure probability of 0.05; and 13 or 51
mm (0.51 or 2.01 in.) for a failure probability of 0.01. These
values are for the carbonation effect only, without cracks in
the concrete; if other factors affecting degradation are taken
into account, the required thickness of the cover will be
greater.
Carbon dioxide will also react with water to form carbonic
acid. There are, however, conflicting data regarding the rate
at which carbonic acid will attack concrete.
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Bertacchi(32) reported, for standard portland cement
concrete, a weight loss of 287 g/kg of concrete and compressive
and flexural strength reductions of -90% after a 7-yr exposure
to distilled water into which CO2 was continuously bubbled and
which was replaced periodically as the dissolved lime content
increased so that its pH varied from ~4 to 5.5. Tremper'30)
reported reductions in compressive strength of 5 to 127. for
portland cement concrete subjected to carbonic acid solutions
of pH 6.9 to 6.1, respectively, for 8 months.
On the other hand, Greschuchna'43) reports that a car-
bonic acid solution saturated at 760 Torr (14.7 psi) and 25°C
(77°P) has a pH of 3.7, and that for pH >3 the corrosion rate
should be hardly greater than that due to leaching by pure
water, i.e. the acid effect becomes negligible. There is also
evidence, however, that carbonic acid attack is enhanced by the
presence of suIfates(^*)t
Tremper'^O) developed a damage function to describe the
deterioration observed in his work. The damage function, which
is expressed as
log L - K-log T,
where L * the percentage of the original lime lost from the
concre te
T * the time in days for which the concrete has been
exposed
K » a constant which varies with the pH of the solution
to which the concrete is exposed and the surface to
volume ratio of the concrete
predicts the rate of detrioration due to acid attack based upon
the loss of lime from concrete. Based upon the results of a
series of laboratory tests, Tremper concluded that for purposes
of computation the mechanical failure of average portland
cement concrete will occur when 50% of the original lime
16
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content has been removed. Values for K are developed based
upon the results of the laboratory tests, however, Tremper had
to make several assumptions during the development of these
values, thereby limiting the accuracy of the damage function.
Tremper does point out, however, that: "It should be borne in
mind that the results (using this damage function) cannot, in
any event, be expected to be more than relative measures since
factors other than corrosion will generally have their effect
in determining actual life." He also points out that he does
not believe that data on the quality of concretes are suffi-
ciently developed to warrent applying (the damage function) in
more than a general way.
published a series of equations for
calculating the depth of the corroded zone for concrete spec-
imens exposed to carbonic acid attack as a function of the
physical and mechanical properties of corroded and noncorroded
specimens, i.e. density, volume, mass, modulus of elasticity,
and strength. The equations, however, do not take into consid-
eration such factors as the composition of the concrete or the
degree of attack to which it is subjected. In addition, the
wide variation in test results, obtained from laboratory tests
performed to varify the theoretically derived equations, limit
their applicability.
Effects of Sulfur Dioxide -
Sulfur dioxide, when dry, has little or no effect on dry
PCC. It does, however, combine with water to form sulfurous
acid (^303), which gradually reacts with oxygen to form sul-
furic acid (t^SC^), both of which will attack concre te . ( 37 )
Most of the damage to materials from SOX is attributed to
highly reactive sulfuric acid formed either in the atmosphere
or on the surface of materials. Damage to limestone products,
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concrete, and marble have been observed in those areas experi-
encing relatively high levels of 802 over a prolonged
period.<27>
As previously discussed, sulfuric acid attacks concrete
(a) by converting calcium carbonate to gypsum, which is subse-
quently leached away, and (b) by reacting with calcium com-
pounds to form salts which crystallize, producing enormous
stresses within the pores of the cement paste which eventually
lead to spalling and cracking. The latter form of attack is
commonly known as sulfate attack. Both mechanisms of deterior-
ation were identified by Hansen et al(35) in their work
regarding the corrosion of concrete due to sulfuric acid
attack, in which they conclude that exposure to sulfuric acid
can progress from a straight corrosive attack to a combination
of corrosion and sulfate attack.
The effects of sulfate attack on portland cement concrete
have been well documented.<28»29»37•38,45-47,50-54) Kuenning
(29) describes the mechanism of sulfate attack as follows:
"The destructive action of sulfates on concrete is primarily
the result of their reaction with either CjA err the C3A hydra-
tion products to form the high-sulfate form of calcium sulfo-
aluminate (ettringite). The crystalline reaction product is of
larger volume than the original aluminate constituent, and
expansion results. The concrete or mortar increases in
strength at first, because of the increase in solid matter,
even though it is changing chemically. As the process contin-
ues the concrete or mortar expands, cracks, becomes progres-
sively weaker, and finally disintegrates."
Jambor'^'' has published a damage function describing
sulfate attack in terms of the percent of 803 bound in hardened
cement paste, which he reports as being the prime cause of sul-
fate corrosion. The damage function (DC) which is expressed as
18
-------
DC - (0.11s0.45)(0<143t0.33)(0>204e0'145c3M
takes into consideration the concentration of the acting sul-
fate solution (S), the period of time of its action (t), and
the tricalcium aluminate (C^A) content of the portland cement
used. The damage function was developed on the basis of exper-
imental test results which demonstrated the effects, with time,
of sodium sulfate solutions, with varying 804 concentrations,
on the dynamic modulus of elasticity, compressive and flexural
strength, volumetric and mass changes, and changes in the bound
content of portland cement mortar specimens.
Jambor has, apparently, been able to relate the changes
observed in the physical and mechanical properties of the spec-
imens to changes in the bound 803 content. These data, how-
ever, were not given in the paper. The data presented relate
bound 803 content to sulfate concentration, C3A content, and
time of testing. It is these data upon which the damage func-
tion was based. As Jambor points out, the damage function is
limited in that it does not take into account temperature
effects, influence of the cement content in the mortars and
concrete, total porosity of the composite material, as well as
the influence of the cross- sec tion size of the structure. It
does, however, serve to give a first approximation.
Even though the mechanisms are not fully understood, it
has been fairly well established that 802 accelerates the cor-
rosion of carbon stee 1 . (18-20 , 55-57 ) xh£s results in the
creation of a layer of rust, i.e. iron oxides, on the surface
of the steel, which occupies more than twice the volume of the
iron from which it was produced. In addition, Haynie and
Upham(19) report that iron oxides catalyze the oxidation of
802 to 803 as well as react with 802 to form sulfates. Both
19
-------
conditions, i.e. the expansion of reinforcing steel due to
corrosion and sulfate attack, have been shown to cause the
deterioration of PCC.
Effects of Nitrogen Oxides -
Very little information is presently available in the
literature regarding the effects of nitrogen oxides (NOX) on
PCC. Gauri^23) reports that nitrogen dioxide produced
primarily during combustion processes by the oxidation of
atmospheric nitrogen is the main cause of the acidity of preci-
pitation in the Los Angeles Basin where N03* is more than twice
as concentrated as SO^"2. H0
-------
deposition. The individuals and organizations contacted are
listed in Appendix B; 14 of them replied to the inquiries. The
letter used in the survey appears in Appendix C.
None of the individuals replying was aware of any documen-
ted information dealing specifically with the effects of acid
deposition on PCC structures, although a few mentioned that
there is some information about the effects of acids and acid
waters, as well as about the effects of acid deposition on
building stone structures. No one was aware of any research
that has been or is presently being done in this area.
The question regarding the need for experimental work got
varied replies. Some thought that the need for research in
this area was open to question because other mechanisms of
deterioration, such as freeze-thaw cycling and chloride-induced
corrosion of reinforcing steel by deicing salts, were more
important. Others thought the need was pressing because the
large volume of concrete structures in the United States could
present a potentially large problem. In fact, Mr. 6. W. DePuy
of the Bureau of Reclamation stated that the Bureau is cur-
rently in the process of formulating a program to determine
which of its projects are in areas with high levels of acid
precipitation so that it can evaluate the need for addressing
the problem of deterioration due to acid precipitation.
Discussions at the Third International Conference on the
Durability of Building Materials and Components held in Espoo,
Finland, August 1984, disclosed that at least one research
effort on the effects of pollutants on reinforced PCC is in
progress. The Building Research Institute in Japan is doing
chamber studies with S02 and CC>2 at two relative humidities,
50% and 90%, but has not yet published any results. The goal of
this work is to develop models for predicting deterioration
rates, and to use the results in establishing design criteria
for the extension of service life.
21
-------
Information from private communications indicated that a
rapidly increasing number of reinforced concrete structures in
cities are showing deterioration attributed to the presence of
high concentrations of S02» Nox» an<* **C1 in the atmosphere.
The mechanism appears to be similar to chloride attack of rein-
forced concrete bridge decks. For example, in areas of South-
east Asia, highly polluted with SC>2 and NOX, cracking in at
least 200 buildings was noted after ~*2 yr, and severe corrosion
occured within 5 yr (e.g. Prof. H. 0. W. Kim, National Univer-
sity of Singapore, personal communication, 1984). In New York
City, highrise multiple dwellings built in the 1950s are show-
ing similar distress. A staff member of one engineering firm
states: "The deterioration on bridge decks due to corrosion is
now being observed in concrete structural members. Corrosion
of vertical members may take longer because of gravity drain-
age, but if the materials and conditions are similar, corrosion
will take place no matter the angle."
SUMMARY
The literature survey, private discussions, and responses
to mail and telephone inquiries have revealed very little
qualitative or quantitative information on the effects of acid
deposition on PCC structures. The rate of deterioration of
reinforced PCC structures in polluted areas appears to be
increasing, and available data make it readily apparent that
acids and acid waters significantly affect the durability of
concrete. The immediate effects of acid deposition on PCC may
not be sudden or dramatic, but the available evidence suggests
that there is cause for concern. When steel reinforcement is
used, as it normally is, the potential for problems is much
greater because acid rain or pollutants eventually reach the
steel via the capillary porosity in the cement phase or through
22
-------
cracks and then will initiate corrosion of the steel, which
subsequently results in cracking and spalling of the concrete.
Dry deposition is anticipated to produce much greater effects
than acid rain, or wet deposition, because it results in much
more concentrated forms of attack. Synergistic effects that
accelerate the deterioration are also presumed to occur.
23
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REFERENCES
1. Galloway, J. N. Acid Precipitation: Spatial and Temporal
Trends. Acid Rain, Proceedings of a Symposium Sponsored
by ASCE, April 2-6, 1979, 1-20.
2. Likens, G. E., and F. H. Bormann. Acid Rain: A Serious
Regional Environmental Problem. Science, 184(4142), 1974,
1176-9.
3. Glass, N. R., et al. Effects of Acid Precipitation in
North America. Environmental International, 4, 1980,
443-52.
4. Fisher, T. When the Rain Comes. Prog. Arch., 7, 1983,
99-105.
5. Stanwood, L. Acid Rain, A Cloudy Issue. The Construction
Specifier, Nov. 1983, 74-9.
6. Gauri, K. L. Effects of Acid Rain on Structures. In:
Proceedings of a Session Held at the National Convention,
ASCE, Boston, MA, April 2, 1979, 70-91.
7. Cowling, E. B. Acid Precipitation in Historical Perspec-
tive. Environ. Sci. Technol., 16(2), 1982, 110A-123A.
8. Martin, H. C. Acid Rain: Impacts on the Natural and Human
Environment. Materials Performance, 21(1), Jan. 1982,
36-9.
9. Likens, G. E. Acid Precipitation. Chem. and Engr. News,
54(48), Nov. 22, 1976, 29-44.
10. Cogbill, C. V., and G. E. Likens. Acid Precipitation in
the Northeastern United States. Water Resources Research,
10(6), Dec. 1974, 1133-7.
11. Berry, M. A., and J. D. Bachmann. Developing Regulatory
Programs for the Control of Acid Precipitation. Water,
Air, and Soil Pollution, 8(1), 1977, 95-103.
12. Trumbule, R. E., and M. Tedeschi. Acid Rain Information:
Knee Deep and Rising. Science Technology Libraries,
4(2), Winter 1983, 27-41.
13. Ashton, H. E., and P. J. Sereda. Environment, Micro-
environment and Durability of Building Materials. Dura-
bility of Building Materials, 1, 1982, 49-66.
24
-------
14. Dornberg, J. The Plaster of Paris Cathedral. Pan Am
Clipper, July 1982, 18-22 and 77-9.
15. Fassina, V. A Survey on Air Pollution and Deterioration
of Stonework in Venice. Atmospheric Environment, 12,
1978, 2205-11.
16. Gauri, K. L. and G. C. Holden, Jr. Pollutant Effects on
Stone Monuments. Environ. Sci. and Technol. 15(4), April
1981, 386-90.
17. Longinelli, A. and M. Bartelloni. Atmospheric Pollution
in Venice, Italy, As Indicated By Isotopic Analyses.
Water, Air, and Soil Pollution, (10) 1978, 335-41.
18. Kucera, V. Effects of Sulfur Dioxide and Acid Precipita-
tion on Metals and Anti-Rust Painted Steel. Ambio, 5(5,6)
1976, 243-8.
19. Haynie, F. H. and J. B. Upham. Effects of Atmospheric
Pollutants on Corrosion Behavior of Steels. Materials
Protection and Performance, 10(11) 1971, 18-21.
20. Ericsson, R. and T. Sydberger. , Influence of S02»
Periodical Wetting and Corrosion Products on the
Atmospheric Corrosion of Steel. Werkstoffe und Korrosion,
31, 1980, 455-63.
21. Schreiber, H. Air Pollution Effects on Materials. Report
for Panel 3 ("Environmental Impact") of the NATO/CCMS
Pilot Study on Air Pollution Control Strategies and Impact
Modelling, 1982.
22. Von Ward, P., ed. Impact of Air Pollutants on Materials.
A Report of Panel 3 ("Environmental Impact") of the NATO/
CCMS Pilot Study on Air Pollution Control Strategies and
Impact Modelling, 1982.
23. Gauri, K. L., Deterioration of Architectural Structures
and Monuments. Polluted Rain (Environmental Science
Research), 17; 1980, 125-45.
24. Dijkstra, G. Effects of Air Pollution on the Materials in
the Netherlands. Report for Panel 3 ("Environmental
Impact") of the NATO/CCMS Pilot Study on Air Pollution
Control Strategies and Impact Modelling, 1982.
25
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25. Skoulikidis, T. N. Atmospheric Corrosion of Concrete
Reinforcements, Limestones, and Marbles. Atmospheric
Corrosion of Concrete Reinforcements and Their Protection,
date unknown, 807-25.
26. Skoulikidis, T. N. Effect of Primary and Secondary Air
Pollutants and Acid Depositions on (Ancient and Modern)
Buildings and Monuments. In: Proceedings of Symposium
and Acid Deposition, A Challenge for Europe, Proceedings
Preliminary Edition, Sept. 1983, 193-226.
27. Gillette, D. G. Sulfur Dioxide and Material Damage. J.
Air Pollution Control Assoc., 25(12), Dec. 1975, 1238-43.
28. Biczok, I. Concrete Corrosion, Concrete Protection.
Akademia Kiado, Budapest, 1972.
29. Kuenning, W. H. Resistance of Portland Cement Mortar to
Chemical Attack - A Progress Report. Highway Research
Record, (113), 1966, 43-87.
30. Tremper, B. The Effect of Acid Waters on Concrete. ACI
Journal, 28(1), Sept. 1931, 1-32.
31. Brown, F. R. Examination of Surface Concrete from Lock
Chamber, Holt Lock and Dam near Tuscaloosa, Alabama.
U.S. Army Corps of Engineers Report, October 6, 1977.
32. Bertacchi, P. Deterioration of Concrete Caused by
Carbonic Acid. In: RILEM Symposium, Durability of Con-
crete-1969, Final Report, Part II, Academia Prague, 1970,
C159-C168.
33. M/odecki, J. Testing the Resistance of Mortars and Con-
cretes to Acid and Carbonic Acid Attack by Stationary
Accelerated Method and by Flow Method. In: RILEM Sympo-
sium, Durability of Concrete-1969, Preliminary Report,
Part II, Academia Prague, 1970, C221-C240.
34. Prudil, S. Effect of Combined Actions of Acid and Frost
on Corrosion of Concrete. In: RILEM Symposium, Durabi-
lity of Concrete-1969, Preliminary Report, Part I, Aca-
demia Prague, 1970, A59-A68.
35. Hansen, W. C., et al. Corrosion of Concrete by Sulfuric
Acid. ASTM Bulletin, 231, July 1958, 85-8.
36. Wong, S. G. Life Expectancy of Concrete Attacked by Acid.
Paper for CE 697D, Purdue Univ., 1978.
26
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37. Woods, H. Durability of Concrete Construction. ACI
Monograph Mo. 4, 1968.
38. Czernin, W. Cement Chemistry and Physics For Engineers.
Chemical Publishing Co., New York, NY, 1962.
39. Sentler, L. Stochastic Characterization of Carbonation of
Concrete. In: Proc. Third International Conference on
the Durability of Building Materials and Components,
Espoo, Finland, Vol. 3, Aug. 12-15, 1984, 569-80.
40. Verbeck, G. Carbonation of Hydrated Portland Cement.
ASTM STP-205, 1958, 17-36.
41. Leber, I. and F. A. Blakey. Some Effects of Carbon
Dioxide in Mortars and Concrete. Journ. Amer. Cone.
Institute, 53-16, Sept. 1956, 295-308.
42. Smolczyk, H. G. New Aspects About Carbonation of Concrete.
RILEM Symposium on Durability of Concrete-1969, Preliminary
Report, Part II, Academia Prague, 1970, D59-D75.
43. Greschuchna, R. Concrete Corrosion and Chemical
Equilibrium. In: RILEM Symposium, Durability of
Concrete-1969, Final Report, Part II, Academia Prague,
1970, C189-C191.
44. Idorn, G. M. Durability of Concrete Structures in
Denmark. Ph.D. Thesis, Technical University of Denmark,
1967.
45. Brown, P. W. An Evaluation of the Sulfate Resistance of
Cements in a Controlled Environment. Cement and Concrete
Research, 11, 1981, 719-27.
46. Heller, L., and M. Ben-Yair. Effect of Sulphate Solutions
on Normal and Sulphate-Resisting Portland Cement. J. App.
Chem., 14, Jan. 1964, 20-30.
47. Jambor, J. Possibilities for More Precise Evaluation of
the Resistance of Concrete to an Aggressive Medium. Dura-
bility of Building Materials and Components, ASTM STP-691,
1980, 301-12.
48. Lea, F. M. The Chemistry of Cement and Concrete. 3rd
Edition, Arnold Publishers, 1970.
49. Friede, H. Depth of the Corroded Zone in Concrete Exposed
to Carbonic Acid. Durability of Building Materials and
Components, ASTM STP-691, 1980, 355-63.
27
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50. Reading, T. J. Combating Sulfate Attack in Corps of
Engineers Concrete Construction. Durability of Concrete,
ACI SP-47, 1975, 343-66.
51. Mehta, P. K. and M. Polivka. Sulfate Resistance of Expan-
sive Cement Concretes. Durability of Concrete, ACI SP-47,
1975, 367-79.
52. Ludwig, V. Durability of Cement Mortars and Concretes.
Durability of Building Materials and Components, ASTM
STP-691, 1980, 269-81.
53. Klieger, P. Durability Studies at the Portland Cement
Association. Durability of Building Materials and Compo-
nents, ASTM STP-691, 1980, 282-300.
54 Mehta, P. K. Performance Tests for Sulfate Resistance and
Alkali-Silica Reactivity of Hydraulic Cements. Durability
of Building Materials and Components, ASTM STP-691, 336-45.
55. Haynie, F. H. and J. B. Upham. Correlation Between Corro-
sion Behavior of Steel and Atmospheric Pollution Data.
Corrosion in Natural Environments, ASTM STP-558, 1974,
33-51.
56. Mikhailovskii, Y. N. and A. P. San'ko. Statistical Esti-
mation of the Influence of Fluctuations in the Atmospheric
Sulfur Dioxide Concentration on the Rates of Corrosion of
Metals. Protection of Metals, 15(4), 1979, 342-5.
57. Ma'tsushima, I. and T. Ueno. On the Protective Nature of
Atmospheric Rust on Low-Alloy Steel. Corrosion Science,
11(3), 1979, 129-40.
28
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APPENDIX A
SUMMARIES OF SELECTED REFERENCES
Reference 4. Fisher, T. When the Rain Comes. Prog. Arch.
(7), 1983, 99-105.
This paper presents a general discussion of the effects
of acid deposition on building materials. It is designed to
give architects a basic understanding of the mechanisms in-
volved in the acid-induced deterioration of buildings. The
author thinks that once architects understand the problem they
can greatly reduce the effects of acid deposition through
proper detailing and material selection. He makes the follow-
ing comments on the deterioration of concrete and other build-
ing materials.
The effects of acid rain on buildings range from minor
surface discoloration to possible destruction of structural
members.
Much of the acid-related damage to structures comes not
from acidic precipitation but from sulfur dioxide and nitrogen
oxide gases directly deposited on and absorbed by building
materials, i.e. "dry deposition." These dry compounds react
with dew or other moisture on a building to form strong acids
that attack the building material on which they are deposited.
The effects of acid deposition depend not only upon the
type of material but on its grain size, porosity, location on
the building, and relationship to other materials. Portland
cement, which contains tricalcium aluminate, is susceptible to
attack by sulfates or sulfuric acid. Silicate materials such
as concrete can produce a soft, colorless material called
kaolin as atmospheric acids accelerate their hydration.
29
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Fisher states: "Many scientists think that acid deposition
damages buildings more through the physical stresses it induces
than through the chemical reactions it brings on." The acids
leave a residue of soluble sulfate and nitrate salts, which
accumulate on or just beneath the surface of the material and
then crystallize with the absorption of water, exerting enor-
mous stresses within the material. These salts create an addi-
tional problem in reinforced concrete, i.e. salt-induced corro-
sion of the reinforcing steel, which increases the internal
stresses developed within the concrete.
The paper goes on to discuss methods for reducing the
effects of acid deposition on building materials.
Reference 5. Stanwood, L. Acid Rain, A Cloudy Issue. The
Construction Specifier, Nov. 1983, 74-9.
The paper presents a general discussion of the threat
posed by acid rain to building materials such as stone, con-
crete, metals, and paints and coatings. It indicates that
materials such as stone and concrete, which contain calcium
carbonate and related compounds, are particularly susceptible
to deterioration in an acid environment.
Sulfur compounds in acid rain react with calcium carbonate
to form calcium sulfate, or gypsum, which is about 30 times
more soluble in water than calcium carbonate and can be rapidly
washed away. Furthermore, the gypsum forming within the base
material can weaken it and at the same time provide a course
for more damaging moisture to penetrate the structure.
Stanwood refers to an interview with Paul Klieger, chair-
man of ACl's committee on durability. Klieger thinks that acid
rain "is an exceedingly minor problem" with concrete and that
"all you would get is a slight etching of the surface," and
30
-------
his committee has not deemed acid rain a problem needing exten-
sive study. Stanwood points out, however, that this statement
applies to concrete, not to the possible corrosion of metals
used in reinforcing a concrete structure, or to the effects of
acid-laden water on sewer pipes and other related structures.
Reference 23. Gauri, K. L. Deterioration of Architectural
Structures and Monuments. Polluted Rain
(Environmental Science Research), 17, 1980,
125-45.
The major objective of this paper is to present the
effects of increased atmospheric toxicity on common materials,
such as natural building stones, brick, concrete, mortar, and
terra-cotta, so that attempts will be made to reduce it.
Gauri states that: "Natural stone, concrete, and mortar
are the common materials exposed at the facade of architectural
structures. Carbonate and silicate minerals are the essential
constituents of these materials. These minerals are suscepti-
ble to attack by atmospheric CC>2 . The weathering of these
minerals has increased at an alarming rate in the industrial
countries due to NOj and 302 emanations."
"The S(>2 attack has produced sulfate crusts on ancient
buildings. The continuing reactivity behind these crusts has
resulted in the removal of stone in layers obliterating the
original sculptural details and causing serious damage to the
s true tures."
"Most ancient buildings and monuments contain flores-
cences. Evaporation of water at the surface tends to accumulate
the florescences in subsurface regions of the stone; their
migration is facilitated by increased ionic concentration
resulting from atmospheric pollution. Repeated dissolution and
31
-------
crystallization of the florescences in subsurface regions and
the accelerated oxidation of reinforcing metals generate
stresses which disintegrate the stone."
Gauri points out that deterioration mechanisms involve
more than just the reaction of the material with atmospheric
gases, the mechnical effects of weathering due to crystalliza-
tion and hydration of florescences, freezing of water, and the
expansion of reinforcement due to corrosion are equally
important.
Reference 24. Dijkstra, 6. Effects of Air Pollution on
Materials in the Netherlands. Report Prepared
for Panel 3 ("Environmental Impact") of the
NATO/CCMS Pilot Study on Air Pollution Control
Strategies and Impact Modelling, 1982.
The paper presents a brief summary of the effects of air
pollutants, mainly sulfur oxides, on materials such as metals,
paints, textiles and building stones. With reference to con-
crete, Dijkstra states: "Cement contains calcium aluminate
which converts in the presence of S02 into ettringite, which by
the large volume change causes cracks in concrete."
Reference 25. Skoulikidis, T. N. Atmospheric Corrosion of
Concrete Reinforcements, Limestones, and
Marbles. Atmospheric Corrosion of Concrete
Reinforcements and Their Protection, date
unknown, 807-25.
The paper reports the atmospheric attack on, and the pro-
tection of, concrete reinforcement, and the sulfation by atmo-
spheric S<>2 of limestones and marbles used in the construction
of ancient monuments and statues.
32
-------
In discussing the corrosion of concrete reinforcement, the
author states: "The increase of atmospheric pollution intensi-
fies the corrosion tendency of the reinforcements in the atmo-
sphere. The cracking of concrete was observed more frequently
with an increase of the atmospheric pollution (SC>2, C02, NH3,
NOX, etc.) and the acceleration of the corrosion by the for-
mation of a more conductive environment, that also chemically
attacks the metals."
Reference 26. Skoulikidis, T. N. Effect of Primary and
Secondary Air Pollutants and Acid Depositions
on (Ancient and Modern) Buildings and Monu-
ments. In: Proceedings of Symposium on Acid
Deposition, A Challenge for Europe, Preliminary
Edition, Sept. 1983, 193-226.
The author discusses the effects of atmospheric pollutants
on the accelerated corrosion of zinc, copper, aluminum, lead,
and steel as bare metals and as reinforcement in concrete, and
also the direct and indirect effects of S02» N0X, C02» H2S04,
and HNC>3 on the deterioration of calcites (such as limestones)
and marble. Regarding concrete the author states: "Air pollu-
tants accelerate the cracking of concrete and consequently the
corrosion of rebars. SC>2 and 803 transform Ca(OH)£ of concrete
to CaS04 a
-------
Most of the material damage associated with SO2 or other
pollutants is caused by long-term exposure. Furthermore, most
of the actual damage from sulfur compounds is due to the forma-
tion of sulfur acids, and 502 represents the best proxy for the
presence of those sulfur compounds.
Sulfur dioxide and its acid derivatives are known to
cause considerable damage to materials, attributed mostly to
highly reactive t^SO^ formed either in the atmosphere or on the
surface of materials. In the absence of adequate moisture, the
amount of material damage caused by SOX would be practically
nil.
Damage to limestone products, concrete and marble, has
been observed in areas experiencing relatively high levels of
S02 over a prolonged period.
34
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APPENDIX B
INDIVIDUALS AND ORGANIZATIONS SURVEYED
Dr. George Lauer
Environmental and Energy
Systems Div.
Rockwell International Corp.
2421 West Hillcrest Dr.
Newbury Park, CA 91320
Dr. Richard G. Stein
The Stein Partnership
20 West 20th Street
New York, NY 10011
Mr. James T. Dikeou
Chairman, Am. Concrete Inst.
(ACI) Committee 124-Research
Quazite Corp.
5515 Gasmer
Houston TX 77035
Mr. Paul Klieger
Chairman, ACI Committee 201-
Durability
Portland Cement Association
5420 Old Orchard Rd.
Skokie, IL 60077
Mr. Charles M. Dabney
Chairman, ACI Committee 303-
Architectural Concrete
L. M. Scofield Co.
6533 Bandini Blvd.
Los Angeles, CA 90040
Mr. Lawrence F. Kahn
Chairman, ACI Committee 364-
Rehabilitation
Georgia Inst. of Technology
School of Civil Engineering
Atlanta, GA 30332
Mr. Mark B. Hogan
Chairman, ACI Committee 531-
Concrete Masonry Structures
Natl. Concrete Masonry Assoc.
P.O. Box 781
Herndon, VA 22070
Mr. James E. McDonald
Chairman, ACI Committee 546-
Repair of Concrete
Waterways Exper. Station
P.O. Box 631
Vicksburg, MS 39180
Dr. Charles Duncan Pomeroy
Cement and Concrete Assoc.
Wexham Springs
Slough SL3 6PL 349620
ENGLAND
Mr. G. W. DePuy
Bureau of Reclamation
P.O. Box 25007/Code 1512
Denver, CO 80225
Dr. Peter J. Sereda
Div. of Building Research
National Research Council
Ottawa, Ontario FC1A OR6
CANADA
Professor Povindar K. Mehta
Dept. of Civil Engineering
Univ. of California
Berkeley, CA 94720
Dr. V. M. Malhotra
CANMET/EMR
405 Rochester St.
Ottawa, Ontario 209660
CANADA K1A OG1
35
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Dr. Geoffrey Frohnsdorff
Chief, Building Materials Div,
National Bureau of Standards
Building 226, Room B-368
Washington, DC 20234
Mr. Larry W. Masters
Building Materials Div.
National Bureau of Standards
Building 226, Room B-343
Washington, DC 20234
Dr. James R. Wright
RILEM President
National Bureau of Standards
Building 225, Room B-119
Washington, DC 20234t
Centre for Research and Devel-
opment in Masonry
No. 105, 4528 6A Street, N.E.
Calgary, Alberta T2E 4B2
CANADA
Mr. Sol Caller
MCP Facilities Corp.
P.O. Box 257
Glen Head, NY 11545
Mr. John M. Scanlon
Chief, Eng. Mechanics Div.
U.S. Army Corps of Engineers
Waterways Experiment Station
P.O. Box 631
Vicksburg, MS 39180
Dr. Gunnar Morten Idorn
G.M. Idorn Consult. Aps.
Tovesvej 14 B
2850 Naerum 299200
DENMARK
Dr. Delia M. Roy
Prof, of Materials Science
Pennsylvania State Univ.
Materials Research Laboratory
University Park, PA 16802
Mr. Howard Kanare
Portland Cement Association
5420 Old Orchard Rd.
Skokie, IL 60077
Dr. Vance Kennedy
U.S. Geological Survey
Water Resources Division
345 Middlefield Rd.
Menlo Park, CA 94025
36
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APPENDIX C
LETTER OF INQUIRY
April , 1984
Dear :
I am writing to you in hopes that you may be able to
assist us in gathering information for a research program cur-
rently underway at Brookhaven National Laboratory.
We are presently involved in the preliminary phase of a
research program funded by the Environmental Protection Agency
to investigate the effects of acid deposition on portland
cement concrete (PCC) structures. As part of this program we
are conducting a survey to determine; (a) if any information
exists regarding problems associated with acid deposition on
PCC, and what the economic impact of these problems may be,
(b) if any research work has been, or is currently being done
to investigate the problems associated with acid deposition,
and (c) if there is a need for experimental work to be done in
this area.
While I realize that these questions are very broad and
complex, any information that you may be able to provide to us
will be greatly appreciated.
Sincerely,
Ronald P. Webster
Materials Research Engineer
RPW:jgm
cc: L. E. Kukacka
37
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing]
1. REPORT NO.
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
EFFECTS OF ACID DEPOSITION ON THE PROPERTIES OF
PORTLAND CEMENT CONCRETE STATE-OF-KNOWLEDGE
S. REPORT DATE
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R.P. Webster and L.E. Kukacka
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Brookhaven National Laboratory
Upton, NY 11973
10. PROGRAM ELEMENT NO.
CCYN1A-08/4063 (FY-85)
11. CONTRACT/GRANT NO.
DW 899307010-01-02
12. SPONSORING AGENCY NAME AND ADDRESS
Atmospheric Sciences Research Laboratory - RTP, NC
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, N.C. 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/09
19. SUPPLEMENTARY NOTES
16. ABSTRACT
Presented are the results of a program conducted to determine the state-
of-the-art knowledge pertaining to the effects of acid deposition on the pro-
perties of portland cement concrete structures. Information was collected from
a computerized literature survey, interviews, and replies to mail and telephone
inquiries addressed to cement and concrete researchers and to governmental
agencies and private firms active in the maintenance and restoration of concrete
structures. In general, the study revealed very little qualitative or quanti-
tative information on the effects of acid deposition on PCC structures. The
rate of. deterioration of reinforced PCC structures in polluted areas, however,
appears to be increasing, and available information makes it readily apparent
that acids and acid waters significantly affect the durability of concrete,
and that SOa, NOX, and HC1 accelerate the corrosion of reinforcing steel.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS fTltisReport)
UNCLASSIFIED
21. NO. OF PAGES
20. SECURITY CLASS (Tills page I
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITION is OBSOLETE
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