Ice aggregate road and method and apparatus for constructing same

A method and apparatus for constructing an ice aggregate structure, such as a road, at all sub-freezing temperatures likely to be encountered at high latitudes, including below -45.degree. F. Initially, ice is mined, crushed and then stripped of substantially all "fines", i.e., ice particles smaller than approximately 0.1 inch. The resulting crushed ice aggregate is then distributed and placed to the desired grade without requiring surface work or compaction. The upper thickness of the crushed ice aggregate is then bonded by spraying heated water thereon during single or multiple passes. Apparatus is provided to prevent evaporative cooling of the spray water prior to its contact with the crushed ice surface, which preferably comprises an enclosure or flexible skirt which extends around the spray nozzles downwardly to the ice aggregate surface. Substantially immediately following the final spray pass, normal wheeled traffic, such as machines utilized to form the ice aggregate road and to transport crushed ice and bond water, can be permitted to traverse the bonded crushed ice aggregate. A preferred embodiment of a crushed ice placement and bonding machine is disclosed which permits a smooth ice aggregate surface to be constructed over uneven terrain. The machine is capable of changing grade as may be required to ramp-on or ramp-off a structure or to clear a natural obstruction, and includes means for incorporating super-elevation (banking) into road curves. The machine is totally self-contained and self-sufficient, and permits construction, on a continuous flow basis, of roads and other civil structures over natural terrain without any machinery contact with the terrain. That is, the machine is capable of operating from the surface that it constructs.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is related to civil structures such as a road for use 
in cold climates, as well as a machine and technique for constructing 
same. More particularly, the present invention is directed towards a 
method and apparatus for constructing a novel road whose principal 
component consists of a crushed ice aggregate. 
2. Description of the Prior Art 
Wintertime work in environmentally sensitive parts of the arctic and 
sub-arctic often requires that access roads, work pads and air strips be 
constructed of non-permanent materials which will not be detrimental to 
the underlying native vegetation. 
The prior art has recognized the unique problems surrounding the 
construction of a suitable roadway in such cold climates. In the past, a 
common solution has been to construct such roads of ice. For example, the 
Rowley et al patent (U.S. Pat. No. 3,986,783) teaches a method and machine 
for constructing ice roads upon snow-covered regions. The machine gathers 
snow from the region upon which the road is to be built, heats the 
gathered snow until it is partially melted and becomes slush, and then 
spreads the slush to form the road upon refreezing. Other U.S. Patents of 
which I am aware which also relate to ice roads formed from snow include 
the Nikolaev et al patent (U.S. Pat. No. 3,371,586) and the Condo et al 
patent (U.S. Pat. No. 3,818,711). 
However, contrary to popular opinion, in many parts of the high latitudes 
very little snow falls, and what does fall is not predictable and seldom 
remains in a uniform distribution over the land surface because of 
incessant transport by the wind. As a consequence, snow is often found to 
be an unreliable material of construction therefore severely limiting the 
known prior art techniques of utilizing snow to construct ice roads. 
In contrast, the occurrence of sub-freezing temperatures and consequent 
freezing of the surfaces of lakes and rivers is highly predictable and is 
uniform over large regions. Ice therefore appears to be a more readily 
available base material from which roadways in cold climates can be 
constructed. Of course, it would be necessary to mine or harvest the ice 
preparatory to constructing the desired road. Fortunately, the technology 
of mining or harvesting ice was developed years ago when such ice was the 
primary source of refrigeration during warmer periods of the year. 
However, to the best of my knowledge, the use of such ice as a 
construction material for wintertime temporary structures such as roads or 
the like has, prior to my invention, not been utilized. 
In a publication entitled: "Building And Operating Winter Roads In Canada 
And Alaska" by Kenneth M. Adam on behalf of the Canadian Department of 
Indian and Northern Affairs, (believed published in 1978), the author 
describes an aggregate ice road whose "development was inspired by Alaskan 
Arctic Gas Pipeline Company as a technique to protect sensitive terrain 
from heavy traffic in areas where a lack of snow or lack of available 
water precludes the use of snow roads or solid ice roads." (Page 59). The 
aggregate ice road described by this author is believed derived from 
earlier studies and experiments I had performed in Fairbanks, Alaska, on 
behalf of the Alaskan Arctic Gas Pipeline Company. The author in this 
publication describes an aggregate ice road constructed utilizing a 
medium-sized tractor to pull the aggregating machine, a front-end loader, 
several dump trucks, a medium sized crawler tractor with blade for shaping 
the road, and a water tanker truck with spray bar for binding the 
aggregate. The technique and apparatus therein described calls for mining 
the aggregate using a roto-tiller and then transporting the ice aggregate 
by front-end loaders and dump trucks to the site. The loaded trucks dump 
the aggregate directly on the site, whereafter the crawler tractor shapes 
the road to the desired width and thickness. Water trucks are then used to 
finish the road by sprinkling with one inch of water. The author concludes 
that: "After sprinkling, several hours should elapse before heavy or large 
numbers of vehicles are allowed on the road. This will allow time for the 
bonds between aggregate particles to freeze solidly before the road is 
opened to traffic." (Page 61). 
While the foregoing article by Mr. Adam summarizes my earlier experimental 
work as of around March, 1977, the state of the art at that time was 
replete with several major disadvantages. Initially, the several large 
pieces of different equipments required to build the road did not lend the 
technique to rapid or efficient construction. Further, my field tests 
conducted in Fairbanks did not encompass all of the conditions likely to 
be encountered in the high latitudes, and, consequently, left many 
questions unanswered. For example, the test sections had been placed over 
a relatively smooth, hard subsurface. Also, although the test sections 
constructed during the field test had successfully withstood severe heavy 
equipment loading, such loading was not done until several hours had 
elapsed from the time of spraying. Finally, the field tests at Fairbanks 
had been conducted with ambient temperatures above 0.degree. F., and no 
actual field experience was obtained at lower temperatures (e.g., 
-20.degree. to -40.degree. F.). 
Since the initial series of tests described above, I have further refined 
my technique for constructing an ice aggregate road in extremely cold 
(e.g., below -45.degree. F.) temperatures, and have developed an apparatus 
which is uniquely designed to construct a smooth ice aggregate surface 
over uneven terrain and which permits near immediate use of the finished 
surface. It is towards this end that the present invention is advanced. 
OBJECTS AND SUMMARY OF THE INVENTION 
It is therefore a primary object of the present invention to provide an ice 
aggregate structure, such as a road, and a method and apparatus for 
constructing same, which overcomes the deficiencies noted above with 
respect to the prior art. 
Another object of the present invention is to provide a practical technique 
for constructing an ice aggregate road in high latitudes where 
temperatures are encountered below -45.degree. F. 
A further object of the present invention is to provide a method of 
constructing an ice aggregate road which provides sufficient strength for 
heavy equipment loading within minutes after construction. 
An additional object of the present invention is to provide a novel and 
unique machine for placing, grading and bonding ice aggregate to the route 
desired for a roadway which is self-contained and self-sufficient and 
which is capable of operating from the surface over which it is 
constructing. 
A still further object of the present invention is to provide an ice 
aggregate placement and bonding machine which is designed to construct a 
smooth ice aggregate surface over uneven terrain, which may change grade 
as required, and which can bank road curves as necessary. 
Another general object of the present invention is to provide a crushed ice 
distributing and bonding machine for constructing, on a continuous basis, 
roads and other civil structures over natural, perhaps uneven, terrain 
without any machinery contact with the terrain. 
The foregoing and other objects are attained in accordance with one aspect 
of the present invention through the provision of a method of building a 
road suitable for use in cold climate, comprising the steps of crushing 
ice to form an ice aggregate, removing most of the ice particles from the 
aggregate which are smaller than a particular size, placing the resulting 
ice aggregate over the route desired for the road, and then bonding the 
upper portion of the placed ice aggregate. The bonding step includes the 
step of spraying water onto the top surface of the placed ice aggregate. 
The bond water is preferably heated. The method further contemplates the 
step of preventing evaporative cooling of the heated spray water by 
substantially enclosing the area between the source of the heated spray 
water and the top surface of the placed ice aggregate. The source of spray 
water may be passed over the top surface of the placed ice aggregate in a 
single pass or in multiple passes. 
In accordance with another aspect of the present invention, there is 
provided apparatus for constructing an ice aggregate road, which comprises 
means adapted to receive ice aggregate for distributing it over a portion 
of the route desired for the road, and means operatively coupled to the 
distributing means for applying bond water to the top surface of the 
distributed ice aggregate. Means are also provided for supporting the ice 
aggregate distributing means and the bond water applying means for 
reciprocal movement over the portion of the road being formed. Means are 
also operatively coupled to the supporting means for transporting same 
from one portion of the road to the next adjacent portion upon completion 
of construction of the first portion of the ice aggregate road. The 
transporting means is adapted for movement over that portion of the ice 
aggregate road just completed. 
In accordance with another aspect of the present invention, means are 
preferably provided for selectively controlling the transverse angle of 
inclination of the supporting means with respect to the portion of the 
road under construction whereby such portion may be constructed with a 
bank. Means may also be provided for interconnecting the supporting means 
and the transporting means for selectively raising and lowering the 
supporting means. 
In accordance with more specific aspects of the present invention, the 
transporting means may include first and second wheeled carriages or 
modules which are respectively positioned adjacent each end of the 
supporting means and which are interconnected by a transverse frame 
member. The space between the first and second wheeled carriages is 
adapted to receive means, such as a dump truck, for providing the ice 
aggregate to the distributing means. The first and second wheeled 
carriages more particularly include means for housing an operator of the 
apparatus, means for containing the bond water, means for pumping the bond 
water to the bond water applying means, means for heating the bond water 
and means for providing transport power. 
In accordance with other specific aspects of the present invention, the 
distributing means comprises hopper means including side walls, an open 
top for receiving, an open bottom for distributing and a rear wall for 
grading the ice aggregate over the portion of the road being constructed. 
The bond water applying means is preferably positioned rearwardly of and 
adjacent to the rear wall of the hopper means. The bond water applying 
means more particularly may include a plurality of spray nozzles connected 
to a common source of bond water and positioned in a spaced relationship 
to the top surface of the distributed portion of the ice aggregate. Means 
are also included for providing a substantially vapor saturated region 
between the spray nozzles and the top surface of the ice aggregate, such 
means preferably comprising means for substantially enclosing the area 
between the spray nozzles and the top surface of the ice aggregate for 
preventing evaporative cooling of the bond water, such enclosing means 
preferably including a flexible skirt. 
In accordance with more specific aspects of the present invention, the bond 
water applying means further includes a source of bond water, a supply 
pipe for delivering bond water to the spray nozzles from the source, a 
return pipe connected to the supply pipe for returning unsprayed bond 
water back to the source, and means for causing continuous circulation of 
the bond water through the source, the supply pipe and the return pipe to 
prevent freezing of the bond water. The spray nozzles each preferably 
include spring-loaded check valve means for preventing spraying of the 
bond water therefrom until the pressure in the supply pipe exceeds a 
predetermined controllable amount. The spray nozzles are preferably 
arranged substantially linearly across the rear edge of the distributing 
means. 
In accordance with yet another aspect of the present invention, there is 
provided a method of constructing an ice aggregate road in cold climates 
using a machine that supports, transports, distributes and grades the ice 
aggregate and bond water, comprising the steps of positioning the machine 
adjacent a first area over which the road is desired to be formed, 
distributing and grading ice particles over the first area with the 
machine, applying bond water to the top surface of the ice particles in 
the first area with the machine, moving the machine onto the bonded ice 
particles in the first area (which may be performed immediately following 
the preceding step), and repeating the preceding steps for a second area 
adjacent the first area. 
In accordance with yet another aspect of the present invention, there is 
provided a roadway for cold climates which comprises an ice aggregate from 
which substantially all ice particles smaller than a predetermined size 
have been removed, and a bonding layer formed in the upper portion of the 
ice aggregate. The bonding layer comprises an ice layer formed by applying 
bond water to the upper portion of the ice aggregate, while the 
predetermined size of ice particles is approximately 0.1 inch in diameter. 
The thickness of the bonding layer is dictated by required structural 
strength, and will be generally in the range of 6-12 inches.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Method 
The technique of the present invention may be summarized as follows. 
Initially, ice must be mined or harvested from any convenient source, such 
as lake ice. The ice may be harvested by any conventional equipment, such 
as a bulldozer. 
The ice is then crushed to a reasonably uniform gradation having particles 
with a maximum size of, for example, three to four inches in diameter. 
Commercially available ice crushers or breakers may be employed for this 
purpose, such as Model 60-300 manufactured by the Lilly Company of 
Memphis, Tenn. 
The preceding two steps may be combined by an in-situ ice crushing step 
that combines both the harvesting and crushing processes. This may be 
achieved, for example, by a roto-tiller type of device. 
The next step in the technique of the present invention is to remove from 
the crushed ice aggregate substantially all of the "fines", i.e., ice 
particles smaller than approximately 0.1 inch. The "fines" removal may be 
achieved by screening the crushed ice by the use of, for example, flat 
deck screens or sieves, a rotary drum screener, or the like. Although the 
theory underlying the importance of removing the fines from the crushed 
ice aggregate is not fully understood, I have discovered that, for a given 
ambient temperature, if the percentage of ice particles measuring 0.1 inch 
in diameter and less of the gradation exceeds a certain value, it is not 
possible under any conditions to construct a bond layer of sufficient 
strength in high latitude climates for wheeled equipment utilization. 
Inasmuch as specified fines control would be difficult, if not impossible, 
under field conditions, the technique of the present invention employs an 
ice aggregate from which substantially all fines have been removed. 
Having removed the fines, the resultant ice aggregate is then transported 
by any conventional means (e.g., truck, belt conveyor, auger) to the site 
desired for the road or other structure. In this step, however, the 
fragile nature and tendency to segregate of the crushed ice must be taken 
into account, and therefore pneumatic conveying, slinging or the like, of 
the crushed ice aggregate should be avoided. 
The next step in the technique of the present invention is to place the 
resulting ice aggregate to the desired grade without surface work or 
compaction. A preferred embodiment of a machine to perform this step will 
be described in greater detail hereinafter. 
The crushed ice aggregate, having been placed to the desired grade, is then 
bonded in its upper thickness by spraying, in either a single pass or in 
multiple passes, its free surface with preferably heated bond water. The 
bond water is preferably emitted from spray nozzles contained within an 
enclosure that effectively seals the space between the nozzles and the 
crushed ice surface to contain the spray water within a vapor saturated 
region. Without such an enclosure, I have found that, at sub-zero 
temperatures, the ice aggregate, having had all fines removed, may be 
sealed from penetration by the bond water. This was believed due to 
evaporation of the bond water in transit from the spray nozzles to the ice 
aggregate, and possibly from the ice aggregate surface itself, such 
evaporation being sufficient to cause subcooling of the bond water 
resulting in the formation of a surface ice sheet that undesirably sealed 
the ice aggregate surface from further penetration by the bond water. The 
enclosure, according to the present invention, prevents evaporative 
cooling of the spray water prior to its contact with the crushed ice 
surface and provides a near 32.degree. F. environment. 
At ice temperatures near and colder than 0.degree. F., the bond water is 
also preferably heated to a temperature inversely proportional to that of 
the crushed ice. Experimental results presently indicate that, for 
example, at -20.degree. F. a 12 inch thick bond layer of considerable 
strength can be obtained with a bond water temperature of about 
100.degree. F. and a bond water quantity on the order of 2.5 pounds per 
square foot. It has been found that an interrelationship exists between 
bond water temperature and bond water quantity for a given strength, with 
a reduction in bond water quantity required as bond water temperature is 
increased, and vice-versa. 
Experimental work has produced ice aggregate roads with thicknesses as 
great as 3 feet and having a 6-8 inch thick bond layer. Road sections of 
greater or lesser thicknesses may be constructed with the present 
invention, as may be desired for particular loading conditions or terrain 
variations. 
Normal wheeled traffic may traverse the bonded crushed ice aggregate within 
seconds of the final spray pass. This is extremely important in that under 
certain conditions in the arctic, environmental considerations do not 
permit traffic over unprotected tundra; hence, a road building system that 
can be constructed from itself, i.e., essentially "unrolled" across the 
desired route, is extremely desirable. 
Apparatus 
The apparatus of the present invention is designed in particular to 
construct a smooth surface of crushed ice over uneven terrain. The 
properties of crushed ice, e.g., low density, lack of abrasiveness, 
flowability, low coefficient of friction and shallow angle of repose, are 
all taken into account in the preferred embodiment. The machine is 
designed to operate from the surface that it constructs; that is, after 
constructing one section of ice aggregate road, the machine is advanced 
over the completed section to construct the next adjacent section, never 
coming into actual contact with the terrain. The machine of the present 
invention is capable of changing grade as may be necessary to ramp-on or 
ramp-off a structure or to clear a natural obstruction. Means are also 
provided for permitting construction of super-elevation (banks) into road 
curves where necessary. The machine of the present invention is totally 
self-contained and is self-sufficient, requiring only a supply of crushed 
ice, bond water and fuel, and is designed to be operated by as few as two 
men. Crushed ice may be transported to the machine over the structure 
constructed by means of, for example, end dump type vehicles, although 
other more efficient means of transport may be used for the crushed ice. 
Bond water may be delivered to the machine in the same manner as the 
crushed ice, although it is possible that a portion of the delivered 
crushed ice may be diverted to an on-board ice melter to provide the 
necessary bond water. 
Referring now to the drawings, wherein like reference numerals represent 
identical or corresponding parts throughout the several views, and more 
particularly to FIGS. 1-6 thereof, reference numeral 10 indicates 
generally a preferred embodiment of a crushed ice placement and bonding 
machine in accordance with the present invention. As illustrated in FIG. 
1, the machine 10 moves from the right to the left as the ice aggregate 
road 14 is being constructed over the underlying terrain 12. The terrain 
12 may be, and is usually, an uneven surface, and may consist of 
ecologically sensitive tundra. The machine 10 of the present invention is 
designed to construct an ice aggregate roadway 14 over the terrain 12 
without having machine contact with the terrain 12 to avoid damage 
thereto. 
The machine 10 of the present invention includes left and right support 
modules or carriages 16 and 18, the contents and functions of which will 
be described in greater detail hereinafter. Each module 16 and 18 is 
supported by a longitudinally extending outrigger frame 20 and transport 
wheels 22. A main frame 24 extends tranversely between modules 16 and 18 
at the forward portions thereof. 
Mounted to the forward portions of modules 16 and 18 and extending 
forwardly over the area of the roadway being formed is a distribution and 
grade box assembly indicated generally by reference numeral 26. The 
distribution and grade box assembly 26 includes a flexible outer guide 
frame 28 and a movable, substantially rectangular distribution and grade 
box or hopper 30. 
The outer guide frame 28 includes rear vertical frame members 32 and 32' 
whose lower ends are connected by a transverse rear frame member 33. This 
structure provides an open rear end for the frame 28, for a purpose which 
will be made clear hereinafter. 
Frame 28 further includes left and right generally C-shaped in cross 
section side frame members 34 and 36 which are preferably pivotally 
mounted to the lower parts of vertical frame members 32 and 32' as at 35 
and 37, respectively. The forward portions of side frame members 34 and 36 
are connected by a front transverse frame member 38. 
Frame 28 is connected to the support modules 16 and 18 by means of left and 
right transport hydraulic cylinders 40 and 42, respectively, and 
associated four-bar linkages 44 and 46 equipped with lateral sway braces 
44' and 46'. This permits the guide frame 28 to be elevated relative to 
the finished ice aggregate surface 14. 
Mounted at the top ends of vertical frame members 32 and 32' are a pair of 
pulleys 48 and 50, respectively, for supporting cables 52 and 54 which are 
connected between the front transverse frame member 38 and left and right 
guide frame warp cylinders 56 and 58, respectively, whose lower ends are 
secured to vertical frame members 32 and 32'. The cylinders 56 and 58 and 
associated cable and pulley assemblies permit the angle of the guide frame 
28 relative to the finished surface to be adjusted up or down. Further, 
the guide frame 28 may be tilted transverse to the direction of travel of 
the machine 10 by differential use of the cylinders 56 and 58. This 
permits construction of a super-elevation (bank) into a road curve, as 
necessary. 
The distribution and grade box 30 consists of a U-shaped, open bottom box 
or hopper that includes side walls 60 and 62 which may include at their 
forward portions slightly inwardly angled edges 61 and 63 for directing 
the flowing crushed ice inwardly when it is dumped into the box 30. The 
box 30 includes a forward compression box bracing member 64 connecting the 
two side walls 60 and 62, and a rear wall 65. A pair of diagonal braces 66 
and 68 are also preferably provided and, together with bracing member 64, 
provide lateral rigidity to the guide frame 28 through the support roller 
assemblies 88, 90, 92 and 94 of the distribution and grade box 30. At the 
lower inside edge of rear wall 65 is preferably provided a crushed ice 
smoothing edge 70 for smoothing the upper surface of the distributed ice 
aggregate. 
The distribution and grade box 30 is adapted for reciprocal movement within 
frame 28 by means of left and right double rod hydraulic cylinders 72 and 
74 which are preferably mounted within the openings of C-shaped side frame 
members 34 and 36 (see FIG. 4). Reference numerals 76 and 78 indicate the 
exposed rods of cylinders 72 and 74, respectively. The distribution and 
grade box 30 is propelled along the guide frame 28 by the attached 
cylinders 72 and 74 which, due to their double rod action, permit equal 
travel velocity in either direction for a given hydraulic fluid flow rate. 
Cylinders 72 and 74 are attached to the box side walls 60 and 62 by means 
of trunnions 80 and 82, respectively. The cylinder rods 76 and 78 are 
attached at each end of frame members 34 and 36 at points 84, 84' and 86, 
86'. 
Two pairs of support roller assemblies are provided on each side of 
assembly 26 for coupling the grade box 30 to frame 28. The roller 
assemblies are indicated generally in FIGS. 1, 5 and 6 by reference 
numerals 88, 90, 92 and 94. As illustrated with greater particularity in 
FIGS. 2-4, roller assembly 88, for example, includes upper and lower 
rollers 96 and 98 connected to the side wall 60 for movement along side 
frame member 34, while roller assembly 90 includes side rollers 100 and 
102 mounted to a common support flange 104 which is also connected to side 
wall 60. Roller assemblies 92 and 94 are similarly constructed and mounted 
for movement along side frame member 36. 
Attached to the rear outside bottom edge of rear wall 65 of box 30 is a 
spray bar assembly indicated generally by reference numeral 106. Referring 
to FIG. 8, a sectional view through the spray bar assembly 106 is 
illustrated and is seen to include an upper metal enclosure 108 and a 
lower metal enclosure 110 within which is positioned insulation 112. A 
vent 114 is preferably formed in upper enclosure 108. Extending 
longitudinally within the spray bar assembly 106 is a heated water supply 
pipe 116 and a heated water return pipe 118. A plurality of spray nozzles 
124 are connected in parallel in communication with supply pipe 116. Each 
preferably include a diaphragm check valve control 120 which requires a 
certain minimum pressure in supply pipe 116 for delivering the bond water 
supply to spray nozzle 124. Any of the bond water not emitted by the 
individual spray nozzles 124 is returned to circulate through the system 
via return pipe 118, as will be described in greater detail hereinafter. 
Extending downwardly from the enclosures 108 and 110 of spray assembly 106 
to the top surface of the ice aggregate 14 is a flexible skirt 122 which 
may be formed, for example, of Hypalon, a synthetic rubber material which 
remains flexible at -40.degree. F. The provision of skirt 122 provides an 
enclosed vapor-saturated region 125 in the spray area to prevent 
evaporative cooling of the spray bond water prior to its impingement upon 
ice aggregate surface 14. In addition to containing the water vapor to 
prevent further evaporation and consequent cooling, flexible skirt 122 
prevents any appreciable build-up of frozen water on its surface. The 
spray bar assembly 106 is attached to the rear of distribution box 30 with 
sufficient clearance to permit flexing of the skirt 122 and consequent 
spalling-off of collected ice. 
Referring now to FIG. 7, reference numerals 130 and 132 indicate side 
extensions of the spray bar assembly which slope downwardly to permit 
bonding of side slopes 138 and 140 of the ice aggregate road 14 if 
desired. The slope bonding spray bar extensions 130 and 132 include skirt 
sections 134 and 136, respectively, which serve the same function as the 
main skirt 122 described above. 
Referring now to FIG. 9, there is illustrated a top sectional view of the 
left support module or carriage 16 which typically may include insulated 
walls 142 and a plurality of access doors 144, 146 and 148. Reference 
numeral 150 indicates an operator control area having windows 152. 
Reference numeral 154 indicates an equipment area which may include, for 
example, an engine/generator 156, a fuel storage area 158, a bond water 
storage tank 160 and a fuel and water transfer mechanism 162 which may 
include hydraulic pumps, for example. 
The right support module or carriage 18 is illustrated schematically in 
FIG. 10 and is seen to include insulated walls 164 and access doors 166 
and 168. Reference numeral 170 indicates an intermediate fluid heater for 
bond water, while reference numeral 172 indicates a heat exchanger and 
circulating pump assembly. Bond water storage is provided in module 18 by 
bond water storage tank 174. 
Referring now to FIG. 11, there is illustrated a schematic representation 
of a heating and circulating system for the bond water which may be 
utilized with the preferred apparatus and technique of the present 
invention. Reference numeral 170 indicates a fluid heater for an 
intermediate, nonfreezing fluid, such as anti-freeze. A fluid circulating 
pump 176 pumps the intermediate fluid through heat exchanger 178 and 
conduit 180 back to fluid heater 170. Bond water contained in storage tank 
174 is pumped by circulating pump 182 through heat exchanger 178 where it 
is heated to the desired temperature. The heated bond water from heat 
exchanger 178 is fed through delivery pipe 186 to the heated water supply 
pipe 116 of spray nozzle assembly 106 via a flexible hose 188 connected 
between the modules and the spray assembly. The return path for the excess 
heated water is by way of return pipe 118, another flexible hose 190 and 
pipe 196 to heated bond water supply tank 160. Pump 182 insures continuous 
circulation of the heated bond water through the spray nozzle assembly 106 
to prevent freezing of the bond water. Between the return pipe 118 and 
pipe 196 is positioned a pressure control valve 192 which is set by the 
operator to establish the required spray nozzle pressure for the desired 
quantity of bond water to emanate from the diaphgram controlled spray 
nozzles 124 in supply line 116. A manual control valve 194 is preferably 
connected in parallel with valve 192 and is used by the operator to bypass 
valve 192 to thereby reduce the pressure in pipes 116 and 118 below the 
set point of the diaphragm check valves 120 (see FIG. 8) to thereby 
prevent water spray without stopping the circulation of the heated water. 
A temperature sensor 184 is provided adjacent line 186 to control the 
fluid heater 170 to maintain the bond water temperature at an operator 
controlled set point which will be a function of the ambient temperature. 
In operation, after harvesting, crushing and removal of the detrimental 
fines, the resultant ice aggregate is dumped into the distribution and 
grade box 30 by means of a conventional crushed ice transporter 128 which 
is adapted to be positioned between the support modules 16 and 18 as 
illustrated in FIGS. 5 and 6. The rear dump type truck 128 is simply 
backed over the finished ice aggregate surface 14 into the space between 
the support modules 16 and 18 and its contents are discharged over the 
forward, transverse main frame 24 into the distribution box 30. 
The ice aggregate is distributed and graded by the forward travel of the 
box 30 propelled by the double rod cylinders 72 and 74 while the support 
modules 16 and 18 are held stationary. The box 30 may be caused to travel 
to the end of the distribution box guide frame 28 if sufficient crushed 
ice is available, or to some intermediate point. During forward travel of 
box 30 (from right to left as illustrated in FIG. 1), the crushed ice 
therein is distributed and graded by the rear wall 65 and the crushed ice 
smoothing edge 70 in combination with the side walls 60 and 62. Spraying 
of the bond water may occur during the distribution and grading pass, or 
in a subsequent pass or passes. In either event, the distribution box 30 
is traversed back and forth within the limits established by the quantity 
of crushed ice available and the terrain fill requirements until the 
desired number of spray passes have been effected. In the preferred 
embodiment, two or three spray passes have been found to be sufficient to 
establish the desired depth of penetration of bond water; however, under 
certain circumstances, more or less bond water passes may be used. It is 
believed from present investigations that the strength of the final 
structure increases with the number of bond water passes. 
Once the requisite number of spray passes have been made, the guide frame 
28 is lifted by the transport cylinders 40 and 42 and the machine is 
propelled forward by the support and transport wheels 22 until the forward 
edge of the bonded ice aggregate is beneath the spray bar assembly 106. 
Alternatively, the guide frame 28 may simply be slid along the bonded 
crushed ice until the unbonded crushed ice edge is reached. 
When the machine 10 has been transported forward to the unbonded crushed 
ice edge, the guide frame 28 is lowered until the rear of the distribution 
box 30 is at the elevation of the bonded ice aggregate. The slope and warp 
of the frame 28 may then be adjusted if any change is to be made for the 
next section of road by means of the cylinders 40 and 42. Additional 
crushed ice is then dumped into the distribution box 30, if needed, and 
the foregoing process is repeated. Incremental slope and warp changes will 
ordinarily be less than 1.degree.-2.degree., and can therefore be easily 
accommodated by the flexible guide frame and distribution box. 
During operation of the machine, flow of the bond water will be continuous 
through the piping system illustrated in FIG. 11 in order to maintain 
freeze protection. When bond water is to be applied, the pressure in the 
flow loop is increased to a value above the opening pressure of the 
diaphragm check valves and to that required for the design flow through 
the respective nozzles. At the end of the spray cycle, the pressure is 
reduced and the check valves close. The heated bond water flowing through 
the pipes in contact with the bottom of the metal enclosure (note FIG. 8) 
will prevent freezing of the water nozzles 124 through conduction. In the 
event that insufficient heat is available for this purpose, supplemental 
heat may be provided, for example, by electric heat cables strategically 
located near the nozzles. 
As may be appreciated from the foregoing, the machine of the present 
invention is capable of constructing an ice aggregate roadway continuously 
from the surface of the structure being built, thereby avoiding machinery 
contact with the underlying terrain. This feature is of extreme importance 
in those areas where the substrate over which the temporary structure is 
being built is ecologically sensitive to high ground pressure loading as 
occurs with most conventional construction equipment. The present 
invention produces a smooth, finished, free surface regardless of 
irregularities in the terrain. The preferred embodiment of the machine may 
be readily disassembled into units of such volume and weight as to be 
easily moved into remote areas by helicopter for use in the construction 
of, for example, air strips for large cargo carrying aircraft, or the 
like. 
The technique of the present invention permits high latitude wintertime 
construction seasons to be extended by both earlier construction in the 
Fall and later utilization in the Spring than is commonly found with more 
conventional snow construction techniques. 
Obviously, numerous modifications and variations of the present invention 
are possible in light of the above teachings. It is therefore to be 
understood that within the scope of the appended claims, the invention may 
be practiced otherwise than as specifically described herein.