DECEMBER 1972
Environmental Protection Technology Series
A Search:
New Technology for
Pavement Snow and Ice Control
I
I
UJ
a
Office of Research and Monitoring
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
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EPA-R2-72-125
December 1972
A SEARCH: NEW TECHNOLOGY
FOR
PAVEMENT SNOW AND ICE CONTROL
by
Donald M. Murray
Maria R. Eigerman
Contract No. 68-01-0706
Project No. Z-800615
Project Officers:
Richard Field
Hugh E. Masters
Storm and Combined Sewer Technology Branch
Edison Water Quality Research Laboratory, NERC
Edison, New Jersey 08817
Prepared for:
OFFICE OF RESEARCH AND MONITORING
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Tor sale by the Superintendent ol Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.00
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EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommenda-
tion for use.
11
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ABSTRACT
A study was undertaken to search for new approaches to the problem of
snow removal and ice control in vehicular and pedestrian usage areas.
Proven techniques of technology transfer were applied for the purpose of
identifying technologies that have not yet been utilized for deicing
purposes. Contacts with specialists and a "brainstorming session" were
used to determine strategies for searches of computerized data banks.
Although several approaches were identified, none are immediately
usable.
Results of the study indicate that: (1) more information is needed-on
salt damage to the environment, paved areas, highway structures, and
vehicles in order to perform accurate cost-benefit analyses of alterna-
tive approaches. (2) More complete knowledge is needed on the effects
of alternate chemical deicers. (3) Pavement heating is an expensive
means of removing snow and ice but can be justified in special cases for
safety or environmental reasons. (4.) Two mechanical devices, snow plow
with compressed air and a brush and blower system require further testing
and development. (5) Research is required to identify a hydrophobia
substance which can be applied to pavement to reduce ice adhesion.
A brief cost estimate of the various approaches has been included.
This report was submitted in fulfillment of Contract No. 68-01-0760 under
the sponsorship of the Environmental Protection Agency.
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TABLE OF CONTENTS
Section Page
I. CONCLUSIONS 1
II. RECOMMENDATIONS 5
III. INTRODUCTION 7
Technology Transfer 7
Problem Identification 7
Technology Identification 8
Technology Implementation 10
IV. STATE OF THE ART REVIEW 11
Chemical Treatment 14
Pavement Heating 15
Ice Adhesion and Release 16
Other Approaches 19
V. DISCUSSION OF FINDINGS 21
New Tire and/or Vehicle Design 21
Negation of Chemical Effects 21
Improved Removal Techniques 22
Prevention of Ice Adhesion By Pavement Heating 25
Prevention of Ice Adhesion By Hydrophobic Surface 27
VI. EVALUATION OF FINDINGS 29
Commonly Used Deicing Chemicals 30
Alternate Chemicals - An Example 31
Chelating Agent 32
Mechanical Devices 33
Pavement Heating 33
Hydrophobic Pavements 36
VII. ACKNOWLEDGEMENTS 38
VIII. REFERENCES 41
IX. APPENDICES 47
A. Sample Computer Search Outputs 48
B. List of Contacts 52
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FIGURES
1. Approach to Deicing 9
2. Fluid Circulating Heat Exchanger 17
3. Electrical Pavement Heaters 18
4, Compressed Air Jet and Snow Plow Blade 24
5. Broom and Blower System 26
VI
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TABLES
Page
I. Mechanical Devices for Snow Removal and 13
Ice Control
II. Pavement Heating System Cost Per Season 35
III. Summary of Cost Evaluation 37
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SECTION I
CONCLUSIONS
The genesis of this report was a mounting concern that the continued
broadcasting of deicing chlorides onto streets, highways, and other
pavements would have irreversibly harmful effects on the environment.
The litany of arguments against chemical solutions to snow and ice
control was familiar:
• Pavement salting causes saline intrusions into ground and ^/
surface waters, contaminating them as habitats for sensi-
tive fresh-water organisms critical in the food chain.
• Brines running off pavements and thrown into the air by \J
passing vehicles contribute significantly to the scorching
and die-off of roadside vegetation.
• Increasing levels of salt in public water supplies pose a
threat to the public's health. Individuals restricted to *'
low-sodium diets may suffer adverse physical effects or be
required to seek alternate sources of supply. In addition,
increased hardness may make existing supplies unfit for
industrial and commercial purposes.
• Increased amounts of salt runoff collected by sewers cannot
\ /
be handled by existing treatment plants; the cost for the
required equipment is very high compared to present facilities.
• Vehicle corrosion is greatly speeded by continual exposure
to salt, in some cases to the extent of structural damage
hazardous to the motorist.
• Corrosion of bridge decks and other highway structures caused
by salt creates an expensive and sometimes dangerous situation.
From all these factors issued the first premise of our study: the
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continued application of vast tonnages of conventional deicing chemicals
and their additives to the pavements of snowbelt states is inimical to
their respective ecosystems and inconsistent with rational policies of
environmental management. This position is not a wholesale rejection
of chemical deicers. Judicious salting in selected areas tolerant of
salt is acceptable.
Our hypothesis is that a search for new techniques constrained to
perform within the bounds of reduced total cost to the public would
reveal innovative technology for snow and ice removal.
By applying a proven method for accessing technology responsive to a
well-defined problem, we explored
1) research and development beyond the state of the deicing
art
2) techniques generated for other applications but unutilized
for deicing
Despite our confidence that this approach would be productive, however,
it must be emphasized that we neither sought nor expected to find
"the answer" to the bare pavement vs. environmental integrity dilemma.
Indeed, there can be no universal solution for what is a highly in-
dividual problem. Blocks of geography have characteristics peculiar
to each of them, making prescriptive findings or "best" practice of
uncertain value. A single technological find, while useful in one
dimension of the deicing problem-say, thermal efficiency-may be
infeasible in some contexts because of another factor, e.g., extra-
ordinary energy requirements.
Searches for new technology have proved to be effective means of
problem solving. However, the method does not guarantee that a solution
exists. In the case of our search for alternate approaches to the snow
and ice problem, technology transfer has been relatively unsuccessful.
The project has found two methods of snow removal which are
useable but require development, and two conceptual approaches which
require further research. If one of the two concepts eventually proves
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to be useful, then the method will have demonstrated its value. If
this is not the case, then the study will have at least enumerated
the existing techniques, demonstrated the nature of the required
solution, and shown that no obvious approaches have been overlooked.
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SECTION II
RECOMMENDATIONS
There have been three major approaches identified by this report:
continue to use salt but find a method for negating its effects,
develop improved mechanical means of removing snow and ice, or
prevent ice from forming or adhering to the pavement. The chief
recommendations stemming from these approaches are:
1) Much more knowledge of salt damage to the environment,
pavement, highway structures and vehicles is a necessity.
A method for assigning costs to the damages must be
devised. Without this information it is difficult or
impossible to accurately assess the benefits of alternate
approaches or justify their implementation.
2) More complete knowledge of the effects of certain alterna-
tive chemicals, including their potential effects on the
environment (i.e. biodegradability, toxicity, etc.), is
required. These are: Ethylene glycol, formamide, urea,
calcium formate, ammonium acetate, Union Carbide's UCAR
Deicing Agent, and proprietary products sold by Kaiser
and Monsanto. It is conceivable that one or a combination
of these chemicals would have a lower total cost to the
public than salt.
3) Pavement heating is an expensive means of removing snow and
ice but can be justified for special locations such as bridge
decks, hazardous intersections, or near water supplies that
cannot tolerate salt. This approach is almost immediately
available for implementation.
4) Pursue testing and development of two mechanical devices:
Compressed air with snow plow and brush and blower system.
5) Pursue search for a hydrophobic substance which can be used
to reduce the adhesion of ice on pavements. While this
approach is the most remote at the present time, it is
potentially the most valuable.
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SECTION III
INTRODUCTION
Technology Transfer
This section describes the methods of technology transfer and the
specific steps taken for the snow and ice problem. Our experience
with technology transfer has involved: (1) the development of
effective and efficient methods for transferring technology from
one context to another and (2) the application of aerospace tech-
nologies to urban problems. The process by which these objectives are
achieved has three major phases: problem identification, technology
identification and technology transfer implementation. The activities
internal to each of these phases are discussed below. It should be
pointed out, however, that the progression of activities for any
one transfer effort is not necessarily sequential, moving from prob-
lem identification to technology searching to technology implemen-
tation. Sometimes these activities proceed simultaneously, sometimes
iteratively. For example, initial work toward implementation of
an identified problem-technology match may require redefining the
problem and subsequently considering alternative technologies.
Problem Identification
Technology transfer occurs at a rather specific level of detail. It
therefore requires that the problem be well-defined. The purpose of
a detailed definition is to provide sufficient description and
analysis of the problem such that the chances of identifying relevant
technology will be maximized. For the current project on snow and
ice removal, a literature review was undertaken to determine various
aspects of the problem, including present-day methods. This review,
and contacts with several engineers (see Appendix B) provided the
basis for generating new approaches. While we found that there was
ample literature on both the physical properties of snow and ice
and on snow removal methods, there was a severe lack of knowledge
regarding salt damage and the safety aspects of salt use. A
major result of our problem identification task was the development
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of an approach to deicing as shown in Figure 1. The first decision box
in the flow chart represents the question, "Should we allow ice and snow
to remain on the pavements with the resultant need for improved tire
and vehicle design, or should we continue to remove it?" The second
decision point represents the question, "Given that we must remove
ice, should we use deicing chemicals or find another approach?" The
third decision box indicates the question, "Given that we will not
use chemical deicers, but must not allow the ice to remain, shall we
remove the ice after it forms or not allow it to form in the first
place?". This flowchart formed the basis for our search for new
technologies.
Technology Identification
This phase of technology transfer involves the generation of many
types of alternative solutions. Besides general contacts with people
knowledgeable of the problem, one of the key components is a "brain-
storming" session. The session is held with engineers and scientists
in an attempt to generate many solution approaches. The "brainstorm-
ing1' technique has proved to be very valuable in past technology
application work and has become an accepted step in the process of
reaching technological solutions. For this project, a session was
held with five senior scientists and engineers from the Massachusetts
Institute of Technology faculty: Professor Clark Colton, Chemical
Engineer; Professor Fred Moavenzadeh, Civil Engineer specializing in
highway problems; Professor Lynn Gelhar, Hydrologist; Professor
David Adler, Electrical Engineer; and Professor David Wilson, Me-
chanical Engineer.
The insights gained from this session were used to develop specific
search strategies for accessing computerized data banks. These
strategies are formulated by alternative combinations of key word
descriptors. For the snow and ice search, three data banks were
accessed - Chemical Abstract Condensates, the National Aeronautic
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J
YES
Develop new tire
and/or vehicle
design.
YES
Mitigate or negate
unacceptable chemical
effects.
YES
Improve removal
techniques, mechanical,
thermal, etc.
Allow Ice to Remain
on Pavements?
NO
\>
Use Salt or Other
Chemical Deicers?
NO
Permit Ice to Form?
NO
Prevent ice adhesion
through special surface
or by pavement heating.
FIGURE 1
Approach to Deicing
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and Space Administration files and the Bibliography on Cold Regions
Science and Technology. In addition, manual searches were performed
on Highway Research Abstracts, Engineering Index, U.S. Government
Research and Development Reports, British Technology Index, Govern-
ment Printing Office Monthly Catalog, Applied Science and Technology
Index, and Highway Research Information Service Abstracts. Sample
pages from the computerized searches are presented in Appendix A.
Upon receipt of the computer printouts, titles of documents were
reviewed for their relevance. Abstracts of these documents were
read and screened a second time. The documents which survived
this second process were then ordered in microfiche or hard copy
form for detailed review.
Computerized searching identifies not only technologies themselves,
but technologists who are involved in continuing research efforts.
It is especially important to discuss a problem directly with the
engineer because documentation can be outdated and significant
advances with a technology may not yet have been recorded. Fur-
ther, he may be aware of related projects in progress elsewhere
which bear more directly on the problem.
Technology Implementation
Once a potentially useful technology is found, it is carefully
evaluated for its technical feasibility. If it appears sound from
the technical point of view, before expending any resources on applica-
tions engineering, it is investigated for its economic feasibility.
This requires an analysis of the characteristics of commercially
available products now attempting to meet the same need. The com-
petitive advantage of the technology over commercial technologies
should be estimated on either a cost or quality basis.
Additional phases of technology implementation include feasibility
testing, performance testing, prototype development, and determination
of production and marketing costs. These subsequent steps, however,
proceed beyond the scope of our project on snow and ice control.
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SECTION IV
STATE OF THE ART REVIEW
An extensive review of the literature and current research on snow
and ice control was undertaken in order to place the study findings
in a proper perspective. It is not necessary here to provide an
exhaustive account of our search since previous studies have described
the range of available equipment and techniques. This section is
intended rather to summarize our overall findings and focus attention
on recent work which has not yet received detailed coverage in the
literature.
Essentially all pavement snow and ice control in the United States
is performed by the long-established methods of plowing, sanding
and salting. While there are numerous types of plows, snowblowers,
and abrasives, and techniques for their use, the basic approach
has remained the same. This is not surprising considering there
has been no continuing program to provide for systematic research
on new equipment, materials and techniques. Government funding
has been scattered and insufficient; industry is not capable of
supporting the type of research required to significantly advance
the state of the art. Thus, what research projects have been
undertaken on either the public or private level have not yet
produced innovative techniques which are economically feasible.
A significant portion of the recent work, both state of the art
reviews and new research, has been performed at U.S. Army Cold
Regions Research and Engineering Laboratory in Hanover, New
Hampshire. This facility sponsors the Bibliography on Cold Region
Science and Technology (1), and has published several other docu-
ments on pavement snow and ice control (3,4). The laboratory
also maintains an extensive library of material on the subject.
Some of their recent research will be discussed later on in
this section.
The Highway Research Board has also published a number of
reports related to pavement snow and ice control (2,5,6,14,16,
36,37,39,54). These reports help to disseminate information
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on the latest devices and techniques. Finally, there are a number
of trade journals (8) which carry a variety of articles on
new equipment and maintenance methods. These journals discuss
materials and equipment which are commercially available for
use. Such publications reach many of the persons who are actually
responsible for winter maintenance efforts.
Beyond the standard methods of plowing, salting and sanding,
many other approaches have been tried. The first of these
are mechanical means aside from simple plowing. Table I lists
the basic types of mechanical devices which are used regularly.
Categories 1 and 2 in the table are conventional devices which
are used regularly. Categories 3 through 6 have all been.tried,
but are not used in an extensive or systematic way. Blowers have
been employed to clear the pavement surface of loose and, especially,
low density snow. However, their use is limited to snow of this
type and they are not capable of directing or piling the snow as it
often must be. Power brooms consisting of engine driven rotary
brushes have been tested for use on airport runways (3). The
brooms have proven to be most useful with wet snow and slush.
They have not been employed on the highway to date.
Ice crushing rollers have undergone limited testing (3). While
they can be used effectively, proper operation is critical to
avoid pavement damage. Ice melting machines consisting of
forced draft oil burners have also been tested at airports.
The burners must be moved over the pavement very slowly. Such
burners do not do a thorough job of deicing and furthermore can
cause noticeable softening of the pavement.
The combinations of equipment listed last in Table I are, of
course, more effective than are the individual pieces of machinery.
The blade and impeller, or blade and cutter combinations have
been used successfully but are not widely available. The broom
and blower combinations have been tested only in prototype form.
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TABLE I
MECHANICAL DEVICES FOR SNOW REMOVAL AND ICE CONTROL
1. Blade or Displacement Plows
1.1 Front Mounted
One-way Blade
Fixed Position (right or left cast)
Reversible (swivel or roll-over)
V-Blade
1.2 Underbody
Road Grader
Truck Mounted
1.3 Side Mounted (wings)
1.4 Trailing
2. Rotary Snow Blowers
2.1 Two-element (impeller)
Auger
Horizontal Axis
Vertical Axis
Swept-back Axis
Cutters
Helical
Horizontal Breakers (rakes)
2.2 Single-element (no impeller)
Scoop Wheel
Drum
3. Pure Blowers
3.1 Compressed Air Jet (compressor fed)
3.2 Combustion Jet (jet engine)
4. Power Brooms (rotary brush)
5. Specialized Ice Removing Equipment
5.1 Ice Crushing Rollers (pressure cutting edges
Wobble Wheel
Spiral Rolls
Serrated Blade
5.2 Ice Melting Machines
6. Combination Equipment
6.1 Blade and Impeller
6.2 Blade and Cutter
6.3 Blade and Compressed Air
6.4 Broom and Blower
6.5 Burner and Blower
6.6 Burner, Broom and Vacuum
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They appear promising for use in removing low to medium volume snow
which is not very hardpacked. As with the blower alone, the broom
and blower combinations often cannot cast the snow far enough or
cast it in the correct direction. There is still a need for improve-
ment of such equipment.
One combination which appears to hold promise for the future is the
use of compressed air in conjunction with a snowplow blade (13). Air
is forced out of the edge of the plow blade and is directed onto the
pavement along the plow's angle to the road. The plow blade does not
make contact with the pavement (thus saving wear on plow blades and
pavement surfaces), as the compressed air lifts the snow off the road
onto the blade. The method works no better than a conventional blade
on ice but is very effective for removing light to heavy snow. To
date, only small shovel-sized models have been tested; a satisfactory
compressor has not yet been found for use on a full size plow.
Chemical Treatment
Chemicals are commonly used on ice pavements to melt and break up
the ice. They can also be used in advance of a snow storm to pre-
vent ice adhesion and snow build-up. Chemical action is a result
of the freezing point depression that occurs in the water, ice and
chemical mixture. Since the degree of depression depends upon the
number of molecules or ions of the chemical in the mixture, the
most effective chemicals are those which ionize in solution and have
low molecular weight. There are a number of soluble salts and
other substances which are capable of substantially depressing the
freezing point. However the choice of chemical is limited by
cost, ease of handling, and degree of damage caused to the pavement
vehicles and the environment. The chief advantage of salt is that
it is both very low in cost and quite effective.
Some of the other chemicals which have been proved effective are:
urea, formamide, urea-formamide mixture, ethylene glycol, ammonium
acetate, tetrapotassium pyrophosphate (KPP), and several proprietary
products. While all of these chemicals eventually biodegrade, the
manner in which this occurs combined with the climatic conditions
determine the effects on the environment. For example, during the
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winter months only a small amount of biodegradation of the accumulating
chemical might occur and, if the chemical were not carried away by
surface or ground water, there would be a high concentration of the
chemical during the spring melt. Such high concentration could cause
serious vegetation damage and abnormal algae growth in surface waters.
Thus the environmental hazards of these chemicals are very dependent
on local conditions. At any rate, these chemicals are very expensive,
the cheapest being almost ten times the cost of salt. At present,
only airports are able to justify this cost through the reduced
occurance of corrosion. Further tests must be performed on all of
the alternate chemicals to determine exactly their dangers to the
environment and their effects on roads and other paved areas, bridge
structures, and vehicles.
Pavement Heating
There have been a number of experiments with heated pavements over the
past several years (17,18,19,20,21,22,22). Such an approach allows
for the melting of snow and ice before any appreciable amount can
form. Some systems have been designed to operate automatically,
sensing the presence of ice or snow and thus removing the need for
observation by an operator. The pavement heater must supply sufficient
heat to melt the ice or snow while simultaneously undergoing the un-
avoidable heat losses both to the ground and to the air. The heat
output required is determined largely by the weather conditions - air
temperature, windspeed, humidity and snowfall rate, but is also
dependent on ground temperature and previously accumulated snow or
ice. There are two types of heaters: fluid circulating systems and
electrical resistance mats.
Fluid circulating systems usually consist of pipes carrying a low
freezing point liquid, heated by an oil-fired furnace or other
device. The pipes are placed a few inches below the surface of the
pavement at the time the pavement is laid. The temperature and cir-
culation rate in the pipes are such that the pavement is maintained
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at 1 or 2° F above the freezing point. The pipes are usually
closely spaced (about 1 to 1 1/2 feet apart) and set in concrete.
There are also circulating systems having no heating element, which
instead use the earth as a heat exchanger (17,18,20,21). This
system utilizes the heat stored in the earth to warm the pavement. One
set of pipes is laid a few inches from the pavement surface as they
are with the regular heating systems, but another set of pipes is
laid 10 - 15 feet below the surface. The two sets are connected and
the fluid in the pipes is circulated by a pump. (See Figure 2)
Although the initial cost of excavation for this system is higher than
with heated systems since pipes must be laid so far below the ground
surface, the operating cost is negligible.
Electrical pavement heaters are of three types: high voltage in-
sulated cable systems, low voltage systems using uninsulated metal
mesh, and electrically conductive pavements (4,23,61). (See Figure
3) These systems work quite well and are less expensive to install
than the fluid circulating systems, although the operating costs are
somewhat higher. Recent experiments (61) with the electrically
conductive pavements have found an encouraging ease of repair and
replacement. Operating costs are very similar to that of the cable
or mesh systems. Electrical pavement heating is most common in
England where a number of sections of road are being tested. Total
annual operating costs are on the order of fifteen to thirty times
that of salt.
Ice Adhesion and Release
One alternate approach is to find ways of reducing the adhesion of the
ice (25,26,27,28,29,30,31,32,33). Most research has been directed
toward solving the ice adhesion problem on equipment and not on
pavements. Although the work may be extended to include pavements,
most substances used have low friction characteristics and could not
be used. This approach has not been fully investigated and is the
subject of further discussion in later sections of this report.
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From pump
To Pump
Pipe Placement in Pavemeat (Top View)
Pavement Surface
Sub-Base
To Pump
From pump
Sand Fill
13 ft.
Heat Exchanger Pipes (Side View)
FIGURE 2
Fluid Circulating Heat Exchanger
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High Voltage Power Supply
High Voltage Cable System
Low Voltage Power Supply
Cable Mesh .
Low Voltage Metal Mesh System
Cable
V
v
Cable
Conductive
Pavement
v
v.
Electrically Conductive Pavement
FIGURE 3
Electrical Pavement Heaters (overhead view)
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Other Approaches
Attempts have been made at using dyes or coal dust sprinkled on the
snow to increase the absorption of solar radiation and thus raise
the rate of melting. Although melting does increase slightly, the
amount cannot justify the application and cleanup costs.
Ultrasonics or vibrational energy techniques have been used to
break up ice on the pavement. While the method should work well
in theory, in practice the energy losses are so great as to make
the process highly inefficient.
Similarly, the use of electromagnetic energy to break up ice has
also proved very inefficient. One test (24) involved the use of
xenon flash lamps to vaporize the ice at the surface of the pavement
causing the surface ice to explode away. While this approach is
certainly a satisfying one, there is little hope that it could ever
be put to practical use because the energy requirements are too great.
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SECTION V
DISCUSSION OF FINDINGS
The literature review and technology reconnaissance generated a
large number of approaches to snow and ice control. Most of these
were found in the literature, and have already been tried in varying
degrees. Some of these were failures; others were not practical
solutions in the sense that they are not both technically and eco-
nomically feasible. For example, the technique of shattering ice
with electromagnetic energy is technically impracticable because
a vehicle could not carry a large enough power generating and ca-
pacitative discharge system; and the idea of- using pavement heating
in all locations is economically unjustifiable. The approaches
described in this section are restricted to those which are either
presently or potentially viable from both an economic and technical
standpoint. The discussion will follow the "Approach to Deicing"
outline in Figure 1.
New Tire and/or Vehicle Design
One obvious direction for research and development is the redesign
of components of the road vehicle itself, such as tire tread or
tire structure, tire accessories, braking systems, suspension systems,
etc. Substantial efforts, chiefly on the part of automobile and tire
manufacturers, have already been made in this area and will continue.
We elected not to pursue this in part because it is already the
subject of active research, but principally because the problem it
poses - that of vehicle design - has wholly different dimensions from
the central concern of the present study - that of clearing road
surfaces. Moreover, it is our belief that vehicle design alone will
not, in the short or medium term, obviate the necessity to free roads
from snow and ice.
Negation of Chemical Effects
A second approach is to allow the continued use of salt or other
chemicals and to somehow alter their effect on the environment. We
would first point out that further testing is required to determine
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the dangers of the alternate chemicals such as ethylene glycol,
formamide, urea, etc. While they are totally biodegradable and could
conceivable be safe under the proper conditions, their total effects
are not well known. It is clear that under some circumstances,
particularly when the chemical level rises in a locality, each of
these can have definitely harmful effects on the environment. Con-
sequently, we suggest that these chemicals be studied more thorough-
ly before attempting to find a method of negating effects which are
not yet well understood.
If the use of salt is to continue at the present level, it appears
that its effects must somehow be counteracted or eliminated. Collection
of the salts after they have served their purpose on pavements would
require special drainage and collection systems which appear wholly
impracticable (not true for salt storage piles, of course). Another
tack is to chemically alter the action of the salt. In theory this
could be accomplished by applying a chelating agent to the highways
after the salt was no longer needed. A satisfactory agent would,
immediately upon contact, tie up most of the sodium ions, making them
unavailable for chemical reactions. A chemical equilibrium would
be maintained between the free sodium and the combined sodium and,
given a sufficient amount of the chelate, the free sodium could be
kept at an acceptable level. However, as the free sodium ions left
the solution via ground or surface waters, more sodium ions would
be released by the chelates. Eventually all the sodium would be
released into the environment (not all in the original location)
although the concentration would be maintained at a reasonable
level. It is questionable whether such an approach would be
effective, or if it would only introduce a time delay in the effect
of the salt. In addition, it would have to be shown that the
chelating agent itself was not harmful to the environment. To
date, a satisfactory chelate has not been identified.
Improved Removal Techniques
If we must keep our paved areas clear of ice and snow, and simul-
taneously restrict our use of chemicals, it is essential that we
devise removal techniques that are more effective than the present
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inadequate methods of plowing and sanding. It is difficult to
predict whether or not a purely mechanical means will ever be developed
capable of completely removing glare ice from the pavement. During
the course of this study we have not been able to pinpoint a feasible
solution, and we doubt that one exists. The adhesive bond that ice
forms with the pavement is often stronger than the cohesive forces
of the pavement itself. Consequently, if one tries to mechanically
break the interfacial bond, the pavement breaks apart first. The
potholes and cracked pavements seen during the winter months
are often the results of a plow being used to "scrape off the ice".
The problem of adhesion does not exist with snow, however, and there
is hope for improving its removal. Dr. C. J. Posey of the University
of Connecticut has worked with the Connecticut Department of Trans-
portation to develop a snow plow blade which works in conjunction with
compressed air to clear the pavement. (13, 62) This device utilizes
a conventional plow blade with an attached air pipe that directs a
thin sheet of high velocity air onto the pavement at the angle of
attack of the blade. (See Figure 4) This stream of air loosens
and lifts the snow so that the plow blade can move it off the road.
The advantages of this system are that:
1) snow in cracks and uneven portions of the pavement can
easily be removed, and
2) the plow does not have to be in contact with the pave-
ment, saving wear on both the road and the blade.
It is thought that with high enough pressure, even dense snow could
be lifted from the pavement. Experiments have been successfully
performed with a shovel-sized test apparatus. Wet snows up to four
inches deep (not tested in deeper snow) were easily cleared from
the pavement. A full size plow was then equipped with a similar
setup and tested on highways. Unfortunately the compressor did not
supply a high enough volume of air and the project has been tem-
porarily suspended until an adequate compressor can be found.
23
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Moldboard
Supply
Air Slot
FIGURE 4
Compressed Air Jet and Snow
Plow Blade
24
-------
One other mechanical approach which merits further development
and testing is a broom and blower system (See Figure 5). The
broom consists of a rotating drum that contains rows of steel bristles.
The broom can be positioned at different angles to change the direction
in which the snow is brushed. The blower follows the broom, clearing
all the loose snow and ice particles left on the surface. The de-
vice works best with heavy snow or slush. Light snow is just
blown around and left behind; hard packed snow is not completely
removed. The brush and blower might be most effectively used
in combination with a snow plow plow on the front, brush under
the truck, and blower at the rear.
Prevention of Ice Adhesion By Pavement Heating
One obvious way to prevent ice adhesion is to prevent ice from
forming at all through the use of heated pavements. Pavement
heating has been tried extensively for nearly 20 years. There
are two major methods of heating. The first type consists of a
fluid circulating system which can either use a fuel burning heat
source (such as an oil burner) or use the earth as a heat source.
The latter has lower operating costs because there are no fuel
supplies or machinery to monitor; however, the initial capital
costs are high because of the requirement for placing a set
of pipes 12 to 15 feet deep under the pavement. The second
type of system utilizes electric power to heat the pavement either
by embedded current carrying cables or by electrically conductive
pavement. The first of these has been more fully tested since
the second is fairly new. However, conductive pavements could
be less expensive for initial installation and for maintenance.
Power requirements are about the same.
Pavement heating is a fairly expensive approach and extensive
use could not be justified. However, it could prove quite valuable
and cost effective in special cases - on bridge decks where
chemical damage cannot be tolerated, at dangerous highway locations
where snow and ice cannot be allowed to remain, or in limited areas
where the environment cannot withstand chemical use.
25
-------
FIGURE 5
Broom and Blower System
26
-------
Prevention of Ice Adhesion By Hydrophobic Surface
The other approach to prevention of ice adhesion is the use of
special road surfacing substances. Many studies have been made
on ice adhesion in general and a few experiments have been performed
on ice releasing agents for aircraft exteriors and outdoor mechanical
equipment. However, little has been done to directly investigate
the use of such agents on pavement. The addition of a hydrophobia
or icephobic (water or ice repellant) substance to a pavement
surface would theoretically produce a significant reduction in the
adhesive forces of any ice that might form. Possibly the movement of
an automobile tire over the surface would cause the ice to crack
or break away, exposing the bare pavement. The pieces of ice
could then be removed by a snow plow. The substances which have
been developed for other applications are not appropriate for
highway pavement because they have low friction characteristics and
would last only briefly on pavement surfaces.
We believe that this approach, reduction of ice adhesion by use
of a hydrophobic substance poses the greatest opportunity for
significantly advancing the art of ice and snow removal. The subs-
tance required must be capable of being applied to existing roads, be
long lasting, have negligible effects on friction, and be reasonably
priced.
While a specific substance which can fill all of these requirements
has not yet been identified, there are a number of existing compounds
which should be tested before new research is begun. These compounds
are all characterized by their ability to form a fairly strong bond
to a surface while leaving no available bonds for water molecules, thus
''repelling" any water that comes in contact with it. There are three
major classes of compounds; Cationic Surface Active Agents, Organo-
Flourochemical Compounds, and Organo Silicone Compounds. Fatty-
quaternary-ammonium compounds, a subgroup of the first class listed
above, might be particularly suitable. Such a compound, when dissolved
in the proper solvent(s), could be sprayed on the road surface pro-
27
-------
ducing the desired film. This film would adhere to the road because
the positively charged cationic agent would be attracted to the neg-
atively charged road surface. Although such a film would repel water
its wearlife can not be predicted easily without testing. A few
specific examples of such a substance are:
"Aliquat H-226", Dimethyl-tallow-ammonium chloride made by General
Mills Chemicals Inc.
"Arosurf TA-100", Dimethyl-tallow-ammonium chloride and "Cationic
Softener-x", Alkyl-imidazoline-derivative both made by Onyx Chemical Co.
"Ceramine H.C.", Fatty amide derivative made by Sandoz Colors and
Chemicals
"Hipochem Aquapruf", Quaternary methylol amide made by High Point
Chemical Corp.
"Scotchgard", a soil repellant chemical made by Minnesota Mining and
Manufacturing Company, is an example of an Organo-Flourochemical compound,
While this specific chemical may not be applicable to the ice release
problem, this class of compounds deserves consideration.
Finally the Organo Silicone Compounds, for example, siloxane resins,
should be evaluated. Two companies involved in the area of silicone
chemistry are Dow Corning and General Electric Silicone Products Depart-
ment.
It is the professional opinion of Dr. Anthony E. Lintner, a
chemical engineer and specialist in surfactants, that it should be
possible to develop a substance that would reduce the adhesion of ice
on pavements. We therefore recommend that research be undertaken in
this direction.
28
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SECTION VI
EVALUATION OF FINDINGS
In order to determine the potential benefits of alternative
snow and ice removal approaches, it is necessary to compare
each to the present method of salting. Such an analysis must
be comprehensive, covering all of the costs involved both tangible and
intangible. Cost estimates for the use of sodium chloride
and calcium chloride cannot be based on acquisition and spreading
costs alone. Costs incurred from damage to automobiles, highway
structures, and the environment must also be evaluated. Unfortunately,
there is a severe lack of knowledge of these costs - especially
the cost to the environment. While there have been a few studies
reporting specific instances of damage to roadside wells (35,36,
40,43,46), ponds (35,40), and vegetation (35,36,39,40,41), there
has been no generalized assessment of the total damage occurring.
In addition, it is difficult to attach monetary figures to the
damage except in cases such as the relocation of wells. How can
one attach a value to mature sugar maples lining the edge of a
highway?
The accelerated corrosion of vehicles which results from contact
with salt has been confirmed (54,55,56). Salt itself is not
corrosive; rather the salt on the surface of the metal causes the
retention of moisture, raising the rate of corrosion to an abnor-
mally high level. A study by the American Public Works Association
(56) has shown that "up to 50 per cent of vehicle corrosion can be
attributed to the action of deicing salt". Estimates of the cost
per vehicle per year range as high as $200. The Society of Auto-
motive Engineers has placed the figure at approximately $100 per
vehicle each year (46, 50). Even if the actual amount were as
low as $50, this would imply a cost of $3 billion per year for
the residents of the snow belt states (based on 60 million vehicles).
Therefore, it would be worth spending as much as $3 billion per year
to avoid the salt damage to vehicles.
29
-------
Damage to pavement and highway structures has also been confirmed
(51). Bridges are especially vulnerable because they are supported
by steel structures which are easily damaged by salt solutions.
Reinforcing rods within the concrete pavement cannot be easily
protected and their corrosion causes the structure to weaken and
the pavement to crack. Unfortunately, cost estimates of the
chemical damage have not been made. One source (51) claims that
without salt, concrete bridge decks could be expected to last
25-30 years before reinforcing was required, but with salt the decks
would last only about 20 years. Based on these estimates, the
maintenance costs of bridge decks is increased by 25-50 per cent
due to chemical damage. However, this figure must be substantiated
by further research before drawing conclusions about the cost of bridge
deck damage. This is also the case with highway surfaces. While
it is generally accepted that deicing chemicals cause scaling and
cracking of pavement, further research must be done to determine
the exact effects of salt.
Commonly Used Deicing Chemicals
The purchase and application costs of salt are fairly well
known. Including delivery to a salt storage and pick-up area,
the purchase cost of sodium chloride ranges from $10 to $20 per
ton. (56) Calcium chloride costs between $30 and $35 per ton.
Dispensing costs have been estimated at $.10 per lane mile for
the vehicle. Labor costs, based on $4 per hour wage and vehicle
speed of 20 mph are approximately $.20 per two-lane mile (since
spreaders normally cover two lanes), or $.10 per lane mile. It should
be noted that in many cases there might be two crew members per truck
and that the work might be done on overtime, raising the labor cost
substantially. Recommended salt application rates for sodium chloride
range from 150 to 400 pounds per lane mile (35,36). Using these
figures, total cost after application could be as low as $1.00 or
as high as $4.40 per lane mile. According to other sources, the
total cost for applied salt is $18 to $25 per ton (58, 59). This
would imply a per lane mile price of approximately $1.40 to $5.00
depending on the application rate. For calcium chloride the price
30
-------
ranges from $2.45 to $7.40 per lane mile
Salt use in Maine is approximately 400 Ibs. per lane mile with
an average of 125 applications per season (35), or a total of
25 tons of salt per lane mile. This implies a cost close to
$500 per lane mile per season. This amount is not unusual -
during the winter of 1966-67, the District of Columbia, Massa-
chusetts, Pennsylvania, and Illinois are known to have applied
20 to 37 tons of salt per lane mile. Since that time, nation-
wide use of salt has grown more than 50 per cent to a present
level of approximately 10 million tons a year at a total cost of
$200 million.
The general lack of knowledge of the damage caused by salt and
the inability to assign costs to much of the damage make it
extremely difficult to make precise cost evaluations. Therefore,
we will use only the costs for salt application and vehicle corrosion
as firm figures in our comparisons. Environmental and pavement damage
costs will have to be left out of the analysis while remembering that
there are very real, and probably significant, costs involved.
Alternate Chemicals An Example
While the findings of this project do not condone the use of chemicals
because of the lack of knowledge of their effects, we present an
example cost comparison for urea in order to demonstrate the im-
portance of considering all costs.
The purchase price of urea is approximately $90 per ton or six times
that of salt. To obtain the same deicing results, 1 - 1/2 to 2 times
the amount of salt required must be used. To replace the 10 million
tons of salt we must use 15 to 20 million tons of urea costing $1.35
to $1.8 billion (whereas the salt cost $150 million). Urea is much
less corrosive to vehicles than salt so let us assume that auto damage
amounts to only $1.5 billion (probably a high estimate) instead of
31
-------
$3 billion for salt. Together with a spreading cost of $75 to $100
million (1 1/2 to 2 times that of salt ) , urea costs between $2.9
and $3.35 billion as compared to $3.2 billion for salt. This demonstrates
the fallacy in the argument that urea would be 9 to 12 times the cost
of salt.
UCAR Runway Deicer made by Union Carbide for airport use also compares
favorably to salt. Its primary ingredient is ethylene glycol. The
chemical causes essentially no corrosion in vehicles and is totally
biodegradable (although this does not necessarily make it safe for
the environment). Its cost is $180 per ton, and approximately 1 1/2
to 2 times the amount of salt is needed for equal melting. Spreading
costs would be about $75-$100 million. Damage to automobiles, pave-
ments and bridges, would be near zero. Consequently, annual costs
would range from $2.8 to $3.7 billion, still a reasonable cost without
even considering the saving on pavement damage. It should be noted
that the $180 per ton price might be lowered if the product were mass
produced.
Chelating Agent
While we do not have a specific chemical to recommend, we will
demonstrate what cost could be justified for its use. Let us assume
that the chelate would reduce the corrosion effect of salt on vehicles
by 50 to 75 per cent (some corrosion will occur since free salt will
be picked up by the vehicles until the chelate is applied). Conse-
quently, corrosion costs would be $.75 to $1.5 billion. Subtracting
$100 million for application leaves $1.4 to $2.15 billion in savings,
which is the maximum amount we could afford to spend on the chelate
to effect a net savings. Dividing this amount by 20 million tons
gives a cost of $70 to $107 per ton. If an adequate chelate could
be found which costs less than this amount, its use would be beneficial.
If the cost of pavement and environmental damage were known and in-
cluded in this evaluation, then the allowable cost for the chelate
would be significantly higher. By not including these costs, we have
arrived at a conservatively low allowable price for the chelate.
32
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Mechanical Devices
The compressed air system and the brush and blower can be considered
similar in their functions. They are able to remove almost all types
of snow but usually very little ice. Their use alone would definitely
reduce, but not eliminate, the need for chemicals. Snow could be
removed more easily and completely without need for salt. In addition,
more complete removal would mean less moisture on the road to form
an ice slick at a later time. Total snow and ice clearing costs per
season (plowing, sanding and salting) in the northeast are estimated
to be $1,000 per lane mile, about half of which is for salt. If we
were able to double the number of trucks (with compressors, etc.,
added) and raise the effective plowing costs by 20 per cent to account
for the increased equipment purchase price, the "plowing" costs would
be about $1,200 per lane mile. At the same time, we could probably
cut the salt use by 50 per cent, reducing the salt cost to $250 per
lane mile. The net increase is $450 per lane mile, about 90 per cent
of the original cost of salt per lane mile. Using the total salt cost
of $150 million, this would imply an increased clearing cost of approxi-
mately $135 million. However, with the salt use cut by 50 per cent
we could expect vehicle corrosion to be reduced. If we assume that the
corrosion damage also drops by 50 per cent, the savings will amount to
$1.4 billion. Even if the plowing were increased five-fold, the
cost savings would still be $.825 billion. This is still a substantial
savings, demonstrating that the introduction of the new mechanical
devices is probably well justified.
Pavement Heating
Pavement heating is a more complete solution to the snow and ice
problem because it eliminates the need for all other procedures -
plowing, sanding and salting. Pavements would be free of snow and
ice at almost all times, further reducing the chance for accidents.
Chemical pollution of the environment would be traded for another
form of pollution resulting from the power requirements for road
heating. While the cost for installing a heating system in a new road
33
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or a paved area is high, addition to an already existing road or paved
area is more than likely out of the question. Thus, the installation
is mainly applicable to paved areas such as new roads, roads undergoing
major resurfacing, shore road spans, or parking and walkway areas which
warrant the addition for safety reasons. The costs for prototype
systems are shown in Table II. The operating costs are for average
winter conditions in the northeast. It is expected that the installa-
tion costs could be reduced once efficient procedures were developed.
To compare the cost of a heating system to the present methods, let
us consider a one mile lane which is 10 feet wide. The area is
approximately 50,000 square feet with a resulting annual operating
cost of $16,000 to $22,000 for an electric system;.$5,000 to $7,500
for a fuel burning system, or about $500 for a heat exchanger.
Comparing this to the present total cost of $1,000 per lane mile per
season, only the heat exchanger would seem reasonable. However, this
system would require a capital cost of at least $300,000 per lane
mile, making it also infeasible for large scale use. The reduction
in vehicle corrosion must be considered. It is clear that the corrosion
cost would be zero if pavement heating replaced salt on all roads.
This is highly unlikely—only a few special locations might use heating
systems with the result that vehicles would still be exposed to almost
the same amount of salt. Highway damage might be reduced at the
location of the heater if salt were not carried from other locations
by vehicles.
Tests to date probably have not shown accurate maintenance costs, which
could be high for the fluid circulating systems. Installation for
the heat exchanger is probably much higher than the cost of the other
systems, possibly making this system unattractive, despite its
extremely low operating costs. It appears that the heating systems can
be justified only in cases where ice and snow are difficult to remove,
where extremly hazardous conditions exist, or where salt poses a serious
threat to highway structures or the environment. Such cases must 'be
evaluated individually—no general rule of thumb can be applied.
34
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TABLE II
PAVEMENT HEATING SYSTEM COSTS PER SEASON
System Type
Installation Cost
Costs (per sq.ft.)
Operating Cost
(per sq.ft.)
Fluid Circulating
Earth Heat Exchanging
Fuel Burning
Electric
Cable or Mat
Electrically Conductive
Not Established
(Estimated $6 - $12)
$4.00
$2.00 - $4.00
$1.00 - $3.00
Less than $.01
$.10 - .15
$.32 - .45
$.32 - .45
(References: 17, 18, S 51)
35
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Hydrophobia Pavements
Although a specific substance has not been identified yet, this analysis
will show the cost constraints for its use. If the surface of our roads
could be made to release the ice, we would eliminate the costs of salt-
ing, vehicle damage, highway damage, and environmental damage. Based
on the first two of these alone, the savings would be approximately $3.2
billion annually. Let us suppose that the substance would have to be
applied once a year, ideally just before the snow season. Suppose also
that there are approximately 1 million miles of road that would have to
be treated - a liberal estimate considering it is about 27% of all the
roads in the U.S. (60). Let us also suppose there is an average of three
lanes per mile, each ten feet wide. Then the allowable cost per square
foot including application costs for the substance is:
$3'2 * 1Q9
1 x 106 mi. x 30 ft x 5280 ft/mi
$.02 sq. ft.
If the substance were able to cover about 250 square feet per gallon,
then the allowable cost would be $5 per gallon including application
costs. If the chemical could be applied by spraying from a moving truck
(as liquid devices are now applied) , the application cost would be fairly
low leaving most of $5 per gallon for the purchase of the substance.
It is extremely important to note that this $5 breakeven figure is low
because we have not indluded any costs for pavement, highway structure,
and environmental damage in the $3.2 billion figure. Inclusion of these
costs could raise the breakeven price considerably.
A number of chemicals have been identified in Section V which would have
the required hydrophobic properties. However all of these are likely to
suffer from at least one main deficiency - short wear life . Tests should
be made to determine their expected life. The cost for some of these
chemicals is as low as $.60 per pound or about $5.00 per gallon. With
the mass production required to produce enough for large scale use, the
price might drop considerably.
A summary of the evaluations in this section is displayed in Table III .
36
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OJ
-j
TABLE III
Summary of Cost Evaluation
(all costs per season)
METHOD OF
SNOW AND
ICE CONTROL
Salt
(Present Method)
Urea
UCAR
Chelate
Mechanical
(Reduced Salt)
Pavement Heaters:
Heat Exchanger
Fuel Burning
Electric Cable
Conductive
Pavement
Hydrophobic
Surface
$
500
4. 5-6. OK
9-12K
S-7P
200
-
-
-
-
1050
'/
-
-
-
-
-
320-600K
215K
102-215K
53-100K
-
£ /// ////&// //* A // A*
/•/ >/ // fff //J A/ // //
fa // fa /£ // /* /f ft*
500
750-1000
750-1000
1.5K
200
-
-
-
-
®
-
-
-
-
1000
500
5-7. 5K
16-22K
16-22K
-
-
-
-
-
-
7
?
7
7
-
-
-
-
-
-
10-20
10-20
10-20
10-20
1
-
-
-
70-107
-
-
-
-
-
1000
.2B
1.4-1.85B
2.8-3.7B
1.7-2.45B^
.3B
NA®
NA®
NA®
«A
3.2B®
3. OB
1.5B
0
.75-1.5B
1.5B
NA
NA
NA
NA
0
3.2B
2.9-3.35B®
2.8-3.7B ®
3.2B ®
NA
NA
NA
NA
3.2B®
K = Thousands of dollars
M = Millions of dollars
B = Billions of dollars
(J) Theoretically allowed
@ Not intended for total replacement of salt
© Included in chemical cost
© Reduced pavement and environmental damage not indicated
© Pavement and environmental damage reduced to zero
-------
SECTION VII
ACKNOWLEDGEMENTS
This project was carried out within Abt Associates Inc., by Donald
M. Murray, Project Supervisor, Maria R. Eigerman, and Richard N.
Foster.
Richard Field, Project Officer and Chief, Storm and Combined Sewer
Technology Branch, assisted by Hugh E. Masters and Anthony N. Tafuri,
Staff Engineers in the Branch at the Edison Water Quality Research
Laboratory, Edison, N. J., monitored the work for the U.S. Environmental
Protection Agency.
Frank Condon, Staff Engineer, Municipal Pollution Control Section,
USEPA, Washington, D.C. conceived the project and provided many useful
insights.
The support of this work by the USEPA and the interest and contributions
of these men, are acknowledged with appreciation.
The advice and assistance given by L. David Minsk, U.S. Army Cold
Regions Research and Engineering Laboratory was greatly appreciated.
39
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SECTION VIII
REFERENCES
1. Bibliography on Cold Regions Science and Technology, U.S. Army
Cold Regions Research and Engineering Laboratory, Report No.
12, Hanover, New Hampshire.
2. Snow Removal and Ice Control Research, Special Report 115, U.S.
Army Cold Regions Research and Engineering Laboratory and
Highway Research Board, Washington, D.C., April 1970.
3. Minsk,L.D. /'Survey of Snow and Ice Removal Techniques," CRREL
Technical Report 128, Cold Regions Research and Engineering
Laboratory, Hanover, N.H., December 1964.
4. Mellor, Malcolm,"Snow Removal and Ice Control," Cold Regions Science
and Engineering Part III, Section A3b, Cold Regions Research and
Engineering Laboratory, Hanover, N.H., April 1965.
5. "Snow Removal and Ice Control Techniques at Interchanges," National
Cooperative Highway Research Program Report 127, Highway Research
Board, National Research Council, Washington, D.C., 1971.
6. Hegmon, R.R. and W.E. Meyer, "The Effectiveness of Antiskid Materials,"
Highway Research Record Number 227, Highway Research Board,
National Research Council, Washington, D.C., 1968.
7. Glauz, W.D., "Watch for Ice on Bridge," MRI Quarterly, Midwest Research
Institute, Kansas City, Mo., Spring 1972.
8. "Snow and Ice Control Methods and Problems," Rural and Urban Roads,
Vol. 10, No. 7, Pontiac, Illinois, July 1972.
9. Anderson, H.E.B.,"Snow on its Way...Will You Move it or Melt it"?
Plant Engineering, Vol. 23, No. 18, Barrington, Illinois,
Sept. 1969.
10. Croce, Karl, "Principles of Snow Removal and Snow-Removal Machines,"
Snow Removal and Ice Control Research, Special Report 115, U.S.
Army Cold Regions Research and Engineering Laboratory and
Highway Research Board, Washington, D.C., April 1970.
11. Tanaka, Yasuyuki,"Snow-removing Performance of the Snowplow Truck,"
Snow Removal and Ice Control Research Special Report 115, U.S.
Army Cold Regions Research and Engineering Laboratory and
Highway Research Board, Washington, D.C., April 1970.
12. Tsuchiya, Raizo and Motoya Inoue,"Current Research on Snow Removal
and Ice Control on Roads in Japan," Snow Removal and Ice Control
Research, Special Report 115, U.S. Army Cold Regions Research
and Engineering Laboratory and Highway Research Board, Washington,
D.C., April 1970.
41
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13. Posey, C.J. "Plow Clean Without Scraping," Snow Removal and
Ice Control Researchr Special Report 115, U.S. Army Cold Regions
Research and Engineering Laboratory and Highway Research Board,
Washington, D.C., April 1970.
14. "Maintenance Practices," Highway Research Record, #94, Highway
Research Board, Washington, D.C., 1965.
15. Maintenance Manual, Department of Public Works, Boston, Massachusetts.
16. "Anti Skid Program Management and Related Papers," Highway Research
Record, #376, Highway Research Board, National Research Council,
Washington, B.C., 1971.
16. "Control of Pavement Slipperiness Asphalt Pavement Cracking," Western
Summer Meeting, Colorado Department of Highways, Highway Research
Board, Washington, D.C. , 1969.
17. Winters, Frank and Sasor, S. Robert, Pavement Heating, Progress Report
1970-1971, New Jersey Department of Transportation, Trenton, N.J.
August 1971.
18. Winters, Frank, Pavement Heating, New Jersey Department of Transportation,
Trenton, N.J., March 1970.
19. Development of a Pavement Heating System to Remove Snow from Airport
Runway Inset Lights, Contract #FA64WA-5183, Federal Aviation Agency,
December 1965.
20. Schaerer, P.A., Melting Snow and Ice by Heating Pavements, National
Research Council, Ottawa, Canada, January 1966.
21. Winters, F.,"Pavement Heating," Snow Removal and Ice Control Research
Special Report 115, U.S. Army Cold Regions Research and Engineering
Laboratory and Highway Research Board, Washington, D.C., April
1970.
22. Watkins, F, "Control of Road Snow and Ice by Salt and Electrical Road
Heating," Snow Removal and Ice Control Research,Special Report 115,
U.S. Army Cold Regions Research and Engineering Laboratory and
Highway Research Board, Washington, D.C., April 1970.
23. Williamson, P.J. and L.E. Hogbin,"Electrical Road Heating," Road
Research Laboratory Report LR 303, Crowthorne, Berkshire, 1969
24. Minsk, L.D., Absorption of Electromagnetic Energy by Ice and Water,
(unpublished paper), U.S. Army Cold Regions Research and Engineering
Laboratory, Hanover, New Hampshire, January 1964.
25. Jellinek, H.H.G.,"Ice Adhesion and Abhesion: A Survey," Snow Removal
and Ice Control Research, Special Report 115, U.S. Army Cold Regions
Research and Engineering Laboratory and Highway Research Board,
Washington, D.C., April 1970.
42
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26. Ackley, S.F. & K. Itagaki, "Ice Adhesion Studies: Properties
of Defects in the Interfacial Region," Snow Removal and Ice
Control Research, Special Report 115, U.S. Army Cold Regions
Research and Engineering Laboratory and Highway Research Board,
Washington, D.C., April 1970.
27• Experimental Use of Urethane Foam Insulation to Control Bridge Deck
Icing, Final Report, Illinois Division of Highways, U.S.
Department of Transportation, June 1969.
28. Millar, Donald M., Investigation of Ice Accretion Characteristics
of Hydrophobic Materials, Final Report, National Aviation Facilities
Experimental Center, Federal Aviation Administration, Washington,
D.C., May 1970.
29. Plump, R.E., Screening of 3M Adhesive Tapes for Ice Releasability,
U.S. Army Cold Regions Research and Engineering Laboratory,
Hanover, N.H., July 1970.
30. Plump, R.E., Comparative Evaluation of Three New Silicone Varnishes
for Ice Release, U.S. Army Cold Regions Research and Engineering
Laboratory, Hanover, N.H., February 1971.
31. Plump, R.E., Ice Adhesion and Release, U.S. Army Cold Regions Research
and Engineering Laboratory, Hanover, N.H., May 1971.
32. Jones, John R., and Michael N. Gardos, "Adhesive Shear Strength of
Ice to Bonded Solid Lubricants," Technical Information Service,
American Institute of Aeronautics and Astronautics, New York,
N.Y., May 1972.
33. Merkle, E.L., Irving Tunnel Tests of Icephobic Coatings, Annual National
Conference on Environmental Effects of Aircraft and Propulsion
Systems, Bordentown, N.J., October 8-10, 1968.
34. Scotto, G.E.,"Liquid Treatments of Commercial CaCl2 in Winter Road
Maintenance," Snow Removal and Ice Control Research, Special Report
115, U.S. Army Cold Regions Research and Engineering Laboratory
and Highway Research Board, Washington, D.C., April 1970.
35. Environmental Impact of Highway Deicing, Environmental Protection
Agency, Water Quality Research, Edison Water Quality Laboratory,
Edison, New Jersey, June 1971.
36. Smith, H.A., Progress Report on MCHRP Project 16-1 Effects of Deicing
Compounds on Vegetation and Water Supplies, National Cooperative
Highway Research Program, Highway Research Board, December 1968.
37. "Environmental Considerations in Use of Deicing Chemicals," Highway
Research Record, #193, Highway Research Board, National Research
Council, Washington, D.C., 1967.
43
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38. Smith, H.A., Environmental Effects of Snow Removal and Ice Control
Programs, Highway Research Board, National Research Council,
Washington, D.C., April 1971.
39. Hanes, R.E., L.W. Zelanzy, and R.E. Blaser, "Effects of Deicing Salts
on Water Quality and Biota, " National Cooperative Highway Research
Program Report #91, Highway Research Board, 1970.
40. Hutchinson, Frederick E., The Influence of Salts Applied to Highways
on the Levels of Sodium and Chloride Ions Present in Water and
Soil Samples, Office of Water Resources Research, Project #A-007-ME,
June 1969.
41. Zelzany, L.W., R.E. Hanes and R.E. Blaser, Effects of Deicing Salts
on Roadside soils and Vegetation, (unpublished), Virginia Polytechnic
Institute Research Division, Blacksburg, Virginia.
42. Hutchinson, F.E., "Effect of Highway Salting on the Concentration of
Sodium and Chloride in Rivers," Research in the Life Sciences,
Winter, 1968.
43. Salt Contamination of Existing Well Supplies, Town of Burlington, Mass.
Whitman & Howard, Inc., Boston, Mass., October 1971.
44. Miller, Edward L., "Models for Predicting Snow-Removal Costs and
Chemical Usage," Snow Removal And Ice Control Research, Special
Report 115, U.S. Army Cold Regions and Engineering Laboratory
and Highway Research Board, Washington, D.C., April 1970.
45. The Use and Effects of Highway De-icing Salts, Commonwealth of
Massachusetts, Legislative Research Council, January 1965.
46. Nisbet, I.C.T.,"Has Salt Lost Favor," Conservation Leader, Lincoln,
Massachusetts 1972.
47. Survey of Salt, Calcium Chloride and Abrasive Use for Street and
Highway De-icing'in the United States and in Canada for 1966-67,
Salt Institute, Alexandria, Virginia 1967.
48. Maintenance Cost Study, Final Report, Ohio Department of Highways,
December 1971.
49. Etude D'Une Formule de Ponderation Des Contrats D'Entretien D'Hiver,
Direction General De La Recherche, Minister de la Voirie,
Quebec, August 1969.
50. Hopt, Roger L., Complete Salting-Sanding Economic Study, Idaho
Department of Highways, Boise Idaho, April 1971.
51. Blackburn, R.R. et al.. Economic Evaluation of the Effects of Ice
and Frost on Bridge Decks, Final Report, Midwest Research
Institute, National Cooperative Highway Research Program,
Kansas City, Missouri, September 1971.
44
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52. Hall, J.N. and S.P. LaHue,"Effect of Salt on Reinforced Concrete
Highway Bridges and Pavements," Snow Removal and Ice Control
Research, Special report 115, U.S. Army Cold Regions Research
and Engineering Laboratory and Highway Research Council,
Washington, D.C., 1970.
53. Winter Damage to Road Pavements, Road Research Group, Organization
for Economic Co-operation and Development, OCED Publications
Center, May 1972.
54. Fromm, H.J.,"Corrosion of Auto-Body Steel and the Effects of Inhibited
De-icing Salts," Highway Research Record Number 227, Highway
Research Board, National Research Council, Washington, D.C.,
1968.
55. Palmer, J.D., "Corrosive Effects of De-icing Salts on Automobiles1,1
Materials Protection and Performance, Vol 10, No. 11, November
1971.
56. Vehicle Corrosion Caused by De-icing Salts, American Public Works
Association Research Foundation, Special Report #34, Chicago
Illinois, September 1970.
57. Wood, F.O., "The Role of De-icing Salts in the Total Environment
of the Automobile," NACE Symposium, March 1970.
58. Personal communication with F.E. Hutchinson, University of Maine,
Oroho, Maine, May 1970.
59. Personal communication with U.S. Geological Survey, Federal
Building, Boston, Massachusetts, May 1970.
60. U.S. Bureau of the Census, Statistical Abstract of the United States:
1971. (92nd edition.) Washington, D.C., 1971, p. 528.
61. Minsk, L. David, "Electrically Conductive Asphalt for Control of
Snow and Ice Accumulation," Highway Research Record , Number 227,
Highway Research Board, National Academy of Sciences, Washington,
D.C., 1968.
62. Kasinskas, Michael M. and Dr. Chesley J. Posey, Development of the
Air Jet Snowplow: Final Report, Connecticut Department of Trans-
portation, Wethersfield, Connecticut, July 1972
63. "Non-Chemical Methods of Snow and Ice Control on Highway Structures1',
National Cooperative Highway Research Program Report 4, Highway
Research Board, National Research Council, Washington, D.C., 1964
64. Water Pollution and Associated Effects From Street Salting, Environ-
mental Protection Agency, Storm and Combined Sewer Technology
Branch, National Environmental Research Center, Edison, New
Jersey, October 1972.
65. "How to Assess the Economics of Urban Snow Problems", Rural and Urban
Roads, pp. 20-21, November 1972
45
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SECTION IX
APPENDICES Page No.
A. Sample Computer Search Outputs
B. List of Contacts 52
47
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APPENDIX A
SAMPLE COMPUTER SEARCH OUTPUTS
The following three pages are sample output from the computerized
searches of Chemical Abstract Condensates, NASA, and the Bibliography
on Cold Regions Science and Technology respectively. The first two
of these have references only; the third includes an abstract. Since
a search strategy must be sufficiently broad to ensure that
all useful references are obtained, a majority of the documents
identified by the search are necessarily irrelevant.
48
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: 910472 SNOW REMOVAL AND ICE CONTROL PERRY
DOCUMENT*
006009
0: CA VOL. 72. A0ST. NO. 006009
i: HYOROPH08IC COATING ON HYDRAULIC
2' HUNG. 800IS, JANOS; PAPP, LNQREJ
3: eO'DJS, JANOS; PAPP, ENDREJ SIMON,
3: C 04B) 22 SEP 1969, APPL. 27 MAY
OBJECTS,
SIMON, AGOSTON; SZERECZ, JANOSJ
AGOSTONl S2EREC2, JANOS; HUXXAT1&6457
1968? 8
CL<
4: HYDROPHOBIC COATINGS CONCRETES, COATINGS HYDROPHOBIC CONCRETES,
DOCUMENT:
006174
0: CA VOL. 72. ABST. NO. 006174
i: WAJER- REPELLANT PERLITE FOR THE ABSORPTION OF OILY LIQUID
2: GER. OFFEN. CULEMEYER, KARL; OIEDRICH, ERWIN CULEMEYER K, DIEDRJCH E.
3: GOLOSCHMIDT, TH. A. G. GWXXBX1807409 CL. B 0J.G) 21 JUN 1969. SWISS APPL.
3; 14 DEC
4: REMOVAL OILS WATERS, GROUND WATERS OIL REMOVAL. OILS REMOVAL
DOCUMENT:
006205
0: CA VOL. 72. ABST. NO. 006205
1- ASSOCIATION COMPLEXES OF PROCAJNE HYDROCHLORIDE WITH SODIUM LAURYL
3: CHEM. PHYS. APPL. SURFACE ACTIVE SOBST, PROC. INT. CONGR. 4TH VILA JATO. J
?.- L, OTERO AENLLE t, CADORNJGA CARRO'R.
3: FAC. PHARM, SAINT JACQUES CQMPOSTELLE, SANTIAGO OE COMPOSTELA. 20UGAG VOL
3= 2, NO. 0, 1967, P. 735- 41.
4: COMPLEXES PROCAINE DEGRADATION, KINETICS PROCAJNE COMPLEXES
DOCUMENT:
015744
0: CA VOL. 72. ABST. NO. 015744
i: INTERACTION OF'SQDIUM ERYTHROSIN AND POLY(VJNYLPYRROLIDONE)
2- J. PHARM. SCI, ANDERSON JC» BOYCE CM.
3= RES. LAB. ASTRA PHARM. PROD. INC, WORCESTER, MASS. JPMSAE VOL 58, NO, 11,
3: 1969, P. 1425- 7.
A- COMPLEX DRUGS,ERYTHROSIN, POLYVINYLPYRROLIDINONE ERYTHROSIN
DOCUMENT:
024229
0: CA VOL, 72, ABST. NO. 024229
15 COMPLEX STUDY OF CONCRETE,
2- SOVERSH. METOD. ISSLED, ISEM, KAMNYA 8ETONA LARIONOVA ZM, NIKITJNA LV,
2! GAHASHIN VR, VOLKOV OS,
3: USSR) 21ABA8 VOL 0, NO. 0, 1968, P. 43- 56,
4: ALUMINATES CA HYQRATED, PHASES HARDENED CEMENT, HYDRATED CA
49
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P^INT 3V2/1-92 TtRMINAL=4i
X63-8CV12 WADD-TR-61-65 AF 33/616/-7G10 61/0
WOO' UNCLASSIFIED DOCUMENT
A/KINDLEY, L. M.
HELPAR, INC., FALLS CHURCH, VA.
MELPAR INC., FALLS CHURCH, VA. DIELECTRIC MOI
STU'«E BARRIER COATING MATERIALS TECHNICAL REPORT,
MAR. 1, 1960 - JAN. 31, 1961 LEE M. KINDLEY URIG
HT-PATTERSDN AFB , OHIO, AERONAUTICAL SYSTEMS DIV.,
APR. 1961 128P 16 REFS /CONTRACT AF 33/616/-701
O/ /WADD-TR-61-65/ UNCLASSIFIED REP3RT AVAILABLE^
J U.S. GOVERNMENT AGENCIES AND U.S. GOVERNMENT CON
TRACTORS OMLY
/ ABSORPTION/ ADHESION/ BARRIER/ BINDER/ CAST/
COATING/ DIELECTRIC/ DISPERSION/ FILLER/ FILM/ MAT
ERIAL/ MOISTURE/ ORGANIC/ RESIN/ STRENGTH/ SURFACE
/ TENSILITY/ TREATMENT/ VAPOR/ VEHICLE/ WATER
X67-85789 NAEC-AML-2505 AD-808920L 66/09/02
UNCLASSIFIED DOCUMENT GOVT, AGCY. ONLY
EVALUATI3N OF FINCH PAINT COMPANY'S PROPRIETARY
COATING SYSTEM /ADHESION TESTS/
A/OHR, J.
NAVAL AIR ENGINEERING CENTER, PHILADELPHIA, PA.
(AERONAUTICAL MATERIALS LAB.)
2 SEP. 1966 13 P REF
/ ADHESION/ ALUMINUM/ EPOXY/ IMMERSION/ PRIMER/
SURFACE/ TEST/ WATER
©bS-84-605 LR-350 NRC-6980 62/07/00 UNCLASSIF
IED DOCUMENT GOVT. AGCY. ONLY
ON THE ADHESION OF ICE TO VARIOUS MATERIALS
A/PRICE, R. D.; B/STALLABRASSt J. R.
NATIONAL RESEARCH COUNCIL OF CANADA, OTTAWA (ONT
ARID). IDIV. OF MECHANICAL ENGINEERING.)
JUL. 1962 23 P REFS
/ ADHESION/ AIRCRAFT/ APPARATUS/ CENTRIFUGAL/ C
DATING/ DRDP/ ICE/ IMPACT/ LOW/ MATERIAL/ PENETRAT
ION/ PORE/ STRUCTURAL/ TEFLON
X65-83063 PTP-851 AO-416611 63/04/16 UNCLASS
IFIED DOCUMENT GOVT. + CONTR. ONLY
PARTICLE ADHESION IN THE PRESENCE OF A LIQUID FI
LM
A/CRUSS, N. L.; B/PICKNbTT, R. G.
CHEMICAL DEFENCE EXPERIMENTAL ESTABLISHMENT, POR
TON (ENGLAND).
16 APR. 1963 21 P REFS
/ ADHESION/ BALANCE/ FILM/ LAYER/ LIQUID/ PARTI
CLE/ SPHERE/ SURFACE/ TORSION
PAGE 1 (ITEMS 1- 4 OF 92)
50
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001 26-2118
100 Hearst, P.J.
2U5 DEICING MATERIALS FOR MILITARY RUNWAYS
501* U.S. Naval Civil Engineering Laboratory. Port Hueneme,
Calif. Technical memoranda
250 #b March 1957/7M-12U
035 AD-ll»3 509
690 DEICERS
652 RUNWAYS
652 TESTS
652 EFFECTIVENESS
7^0 Deicing materials for melting ice on runways
520 Various noncorrosive chemicals were investigated to determine
their suitability and effectiveness as materials for melting
ice on runways. Properties studies included, the ability to
lower the freezing point of water, the heat of solution, and the
rate of melting ice. It was found that in order to have a
reasonably high rate of melting ice, a deicing material must be
heavier than water. Formamide containing 20 per cent urea and
5 per cent water as freezing point depressants is the best deicing
material found for use at temperatures as low as -18 degrees
centigrade ( 0 degrees Fahrenheit). This mixture is effective
at still lower temperatures if a certain amount of slush formation
can be tolerated and if it is applied at temperatures no lower
than about -18 degrees centigrade.^At much lower temperatures
ammonium acetate may be a satisfactory deicing material.
501 b
502 h
008 15.eng 20.m 21.5703 23.us
.51
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APPENDIX B
LIST OF CONTACTS
The following persons and agencies were contacted in regard to the project:
L. David Minsk
U.S. Army Cold Regions Research and Engineering Laboratory
Hanover, N. H.
Adrian G. Clary
Highway Research Board
Washington, D.C.
Charles Dougan
Bureau of Research and Development
Connecticut Department of Transportation
Dr. C.J. Posey
University of Connecticut
Bernard Chaiken
Chemistry and Coatings Group
Federal Highway Administration
Harry Smith
National Cooperative Highway Research Program
Highway Research Board
J. Allan Schofield
Union Carbide Corporation
Tarrytown, New York
52
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William Latham
Kaiser Chemical Co.
Savannah, Georgia
Jack Slater
Kaiser Chemical Co.
Savannah, Georgia
William Tyler
NASA Scientific and Technical Information Facility
College Park, Maryland
Mark HeIyer
New England Research Applications Center
Storrs, Connecticut
Edward Perry
New England Research Applications Center
Storrs, Connecticut
John Feulner,
National Referral Center
Library of Congress
Geza T. Thuronyi
Cold Regions Bibliography Project
Library of Congress
Professor Clark Colton
Chemical Engineering
Massachusetts Institute of Technology
Professor Lynn Gelhar
Hydrology,
Massachusetts Institute of Technology
53
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Professor David Adler
Electrical Engineering
Massachusetts Institute of Technology
Professor David Wilson
Mechanical Engineering
Massachusetts Institute of Technology
Department of Public Works
Control and Research Laboratory
Montreal, Canada
Department of Transportation
State of Illinois
Department of Transportation
Division of Research and Development
Bureau of Instrumentation Services
Trenton, New Jersey
Department of Highways
State of Ohio
Division of Building Research
National Research Council
Ottawa, Canada
Road Research Laboratory
Ministry of Transport
Crowthorne, Berkshire
England
Ministere de la Voirie
Gouvernement du Quebec
Quebec, Canada
54
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Professor Frederick Moavenzadeh
Mechanical Engineering
Massachusetts Institute of Technology
Dr. Anthony E. Lintner
Chemical Engineer Consultant
Pittsburgh, Pennsylvania
William Burling
Department of Public Works
Burlington, Massachusetts
Professor Robert C. McMaster
Department of Welding Engineering
Columbus, Ohio
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
'/. Title
A Search: New Technology for Pavement Snow and
Ice Control
e. 10/1/72' ;.
S. f- .•rfotrnr, g Orgai..zafion
. ^utiierfi.'Donald M. Murray
Maria R. Eigerman
P. Organization
Abt Associates Inc.
10, Project No,
11. Contract/Giant No.
68-01-0706
! LIf Repot -i fani
eted
Supplementary Notes
Environmental Protection Agency report
number, EPA-R2-72-125, December 1972.
16. Abstract
A study was undertaken to search for new approaches to the problem of snow removal and
ice control. Proven techniques of technology transfer were applied for the purpose of
identifying technologies that have not yet been utilized for deicing purposes. Contracts
with specialists and a "brainsterming session" were used to determine strategies for
search of computerized data banks. Although several approaches were identified, none
are immediately useable.
Results of the study indicate that: (1) More information is needed on salt damage to the
environment, highway structures, and vehicles in order to perform accurate cost-benefit
analyses of alternative approaches. (2) More complete knowledge is needed on the effects
of alternate chemical deicers. (3) Pavement heating is an expensive means of removing
snow and ice but can be justified in special cases for safety or environmental reasons.
(4) Two mechanical devices, snow plow with compressed air and a brush and blower .system
require further testing and development. (5) Research is required to identify a hydro-
phobic substance which can be applied to pavement to reduce ice adhesion.
brief cost estimate of the various approaches has been included.
rhis report was submitted in fulfillment of Contract No. 68-01-0706 under the sponsor-
ship of the Environmental Protection Agency.
17a. Descriptors
17b. Identifiers
Send To:
WASHINGTON. O C. 2O24O
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