i
An Analysis of Infrared Asphalt Repair
Technology for the Pittsburgh Public Works
Prepared by Max Goetschel, August 15th
, 2014
It is commonly understood that Pittsburgh’s streets are in need of serious repair. In 2014,
Public Works (PW) Director Mike Gable admitted that 60% of all asphalt streets in Pittsburgh–
over 550 lineal miles– have a rating of “zero”, as in being in the worst condition possible.1
Coupled with the unusual harshness of last winter, the city’s 311 Call Center received over
6,000 pothole complaints in the first three months alone.2
This report recommends that Pittsburgh Public Works explore alternative street
maintenance technologies in order to increase the efficiency and reduce the overhead costs of
asphalt repair jobs. The technology that this report focuses on is infrared asphalt repair systems.
The infrared method can perform seamless patches that can last up to 14 times longer than the
throw-and-roll method currently used today, and has also been shown to cost substantially less
over time. Infrared methods are also highly flexible, and can be used to dramatically improve
repairs on utility cuts, alligator cracks, settlement, longitudinal cracks, bumps, low spots, seam
bonding and manhole cover ramping.
1 Bauder, Bob. "Peduto Bemoans Pittsburgh Potholes, Says Most Complaints Addressed." TribLIVE.com. Pittbsurgh Tribune
Review, 2 Apr. 2014. Web. 08 Aug. 2014. 2 Balingit, Moriah. "Pothole Complaint s Top 6,100 in Pittsburgh." Post-gazette.com. Pittsburgh Post-Gazette, 2 Apr. 2014.
Web. 08 Aug. 2014.
ii
Contents
Overview of Current System......................................................................................................................... 1
Infrared Asphalt Repair Technology ............................................................................................................. 1
Method ...................................................................................................................................................... 1
Pros ........................................................................................................................................................... 2
Cons .......................................................................................................................................................... 4
Findings from Other Cities & Counties ........................................................................................................ 5
East Lansing, MI: Cutting Costs on Asphalt Purchases ............................................................................ 5
Columbus, OH: Battling Winter Potholes with Infrared ........................................................................... 5
Tallahassee, FL: “Flawless” Utility Cut Repairs ...................................................................................... 6
Bartow County, GA: Less Trucks, Less Workers ..................................................................................... 6
Fall River, MA: Hot-Mix Repairs all Year Round ................................................................................... 6
Policy Recommendations .............................................................................................................................. 7
Conclusion .................................................................................................................................................... 7
Appendix ....................................................................................................................................................... 9
Step-by-Step Process ................................................................................................................................ 9
Local Infrared Repair Laws .................................................................................................................... 11
Point Pleasant Beach, NJ .................................................................................................................... 11
Bloomingdale, NJ ............................................................................................................................... 12
Greenville County, SC ........................................................................................................................ 12
Randolph, ME .................................................................................................................................... 13
1
Overview of Current System
Pittsburgh’s Public Works (PPW) Street Maintenance Division maintains 866 lanes miles
of asphalt streets.3 This year, city council added $1.2 million worth of diverted funds to street
resurfacing.4 While this increase in funding was made to compensate for this winter’s unusually
vicious weather, a small portion of this fund could also be used to explore alternative pothole
repair methods, in order to increase the overall efficiency of our street repair methods as well as
save the city time and money in the long run.
This report assesses the costs and benefits of adding infrared asphalt technology to our
street maintenance division. Infrared was chosen because of its recent surge in popularity among
municipalities in New Jersey, Michigan, and Ohio: states that have climates similar to our own.
Other methods– such as UPM cold patch or green asphalt– were not included in this report, due
to their prohibitive costs and failure to address the current needs of Pittsburgh.
PPW uses the throw-and-roll system as its primary method for repairing potholes. This
method is the oldest and most popular form of pothole repair jobs because it’s fast, easy, and
requires little technology. The process involves cleaning the pothole of water and debris, pouring
hot-mix or cold-mix asphalt into the hole, and compacting the newly placed material with a
roller. The benefits behind throw-and-roll is the short amount of time it takes to complete the job,
as well as the low amount of training needed to perform the patch. The costs, however, are steep:
cold-mix throw-and-roll patches typically only last 3 months, and must be re-patched later in the
year5. Even hot-mix throw-and-roll patches. Using hot-mix asphalt makes more permanent
repairs than cold-mix, but can also lead to permanent patch failure if the process is not correctly
sealed.6 7 8
Infrared Asphalt Repair Technology
Method
The infrared method consists of two main components: an infrared reclaimer and a
pavement heater. The reclaimer is essentially a portable heater that keeps the hot-mix asphalt at a
workable temperature (between 250-350F). The pavement heater is capable of heating the
3 The entire Operations Department also maintains 90 lane miles of concrete streets, 80 lane miles of brick and block stone
streets, 22 lineal miles of City steps, 44,000 street lighting fixtures, 850,000 street signs, 9,272 lots owned by the city, 195 park
facilities & various green spaces, 330 outdoor courts, 128 sports fields, and 129 play areas. 4 City Council Resolution 2014-0365. Pittsburgh City Council Resolutions. 2014. Pittsburgh. Municipal Archives.
5 Wilson, T. P., and A. R. Romine. Materials and Procedures for Repair of Potholes in Asphalt-Surfaced Pavements. Tech. no.
FHWA-RD-99-168. McLean: Federal Highway Administration, 1999. Print. 6 Kubanek, Kathrin. POTHOLE: Final Report. Rep. no. 832700. 5th ed. Vol. 10. N.p.: ERA-NET ROAD, 2013. Print. 7 Ipavec,, Aleksander. Study of Existing Standards, Techniques, Materials and Experience with Them on the European Market.
Rep. no. 832700. Vol. 3. N.p.: ROAD ERA NET, 2012. Print. 8 Nazzal, Munir D., Ph.D., P.E., Sang-Soo Kim, Ph.D., P.E., and Ala R. Abbas, Ph.D., P.E. Evaluation of Winter Pothole
Patching Methods. Rep. no. FHWA/OH-2014/2. N.p.: Ohio Department of Transportation, 2014. Print.
2
existing pavement surface, within and around the area to be patched, to a workable temperature
close to 320F without burning or oxidizing it.
Once the area needing repairs is heated to the appropriate temperature, the area is raked
for higher permeability. Then, the virgin hot-mix asphalt is removed from the reclaimer and
placed into the pothole area, easily blending in with the existing asphalt material and allowing
for a seamless patch that doesn’t allow water to leak in, leading to rapid deterioration of the
repair and permanent patch failure. Figure 1 illustrates the typical design for a trailer-mounted
infrared asphalt repair system.
Figure 1: General Set-Up of a Tow-Behind Combination Infrared Machine
Source: Evaluation of Winter Pothole Patching Methods, Ohio University & ODOT Report
The newly applied asphalt is then luted to form a level cap over the damaged area. Once
that asphalt is in place, a roller must press the area down to form a level cap, starting with the
seams and working its way in. No loud machinery is required, which allows repairs to be
conducted at any time of day without disturbing local residences.9
Infrared can also be used to remove excess asphalt, smooth existing patches, and re-seam
a previous patch job without having to cut into anything. An infrared machine essentially
removes the need for a saw for any kind of job, and uses far less asphalt and labor hours in the
process.
Pros
One of the main causes of patch failure when using the throw and roll and spray injection
methods is due to an inadequate bonding between the patching material and the existing colder
pavement material surrounding the pothole. The temperature difference can result in the
separation of the two materials, which in turn creates a point of entry for debris and water to
9 A detailed explanation of this entire process is in the appendix of this report, and was written by the Ohio Department of
Transportation in partnership with University of Ohio & University of Akron.
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penetrate and may ultimately lead to the failure of the patch. 10
Infrared solves this problem by
heating the existing material to a comparable temperature, rejuvenating the old pavement and
fusing it to the new asphalt. That new asphalt can contain high proportions of used asphalt,
which can substantially reduce new asphalt purchases. This feature is why infrared repair is one
of the most environmentally friendly methods of asphalt repair in the field.
The infrared method is also known to be highly flexible: after talking with ten different
street supervisors and road directors from across the country, this report found that infrared
machines are also being used in utility cuts, settlement, cracks, bumps, low/high spots, potholes,
seam bonding and manhole cover ramping.11
No milling is required when conducting a repair.
Infrared asphalt repair is so effective at utility cuts that this report found six different
municipalities and counties with laws that require every utility cut to be repaired using infrared
technology.12
The University of Ohio partnered with the Ohio Department of Transportation (ODOT)
to conduct a comprehensive analysis of the infrared method.13
Their report found that the
infrared patches had much higher quality ratings than those installed using either the throw-and-
roll or spray injection methods, and are expected to survive up to 14 times longer. 14
Figure 2: Overall Rating with Time for Each Patching Method
Source: Evaluation of Winter Pothole Patching Methods, Ohio University & ODOT Report
10 Munir, Kim, & Abbas ibid. 11 For an expansion on these usages, consult the Findings section. 12 For a list of specific infrared utility cut laws, consult the Appendix section. 13 To request a copy of this report, email [email protected] 14 Munir, Kim, & Abbas ibid., 83
4
The study also conducted a survey of private companies and municipal governments
who’ve purchased an infrared machine, and over 90% of the survey respondents said their
machine had higher longevity and was more cost-effective than existing pothole repair
methods.15
16
The report concludes that while infrared does cost more than the throw-and-roll method
in the initial 12 months, infrared becomes more cost-effective afterwards due to the long-lasting
repair job, which makes up for the cost of re-doing a patch later down the road.17
The method is
also labor saving: only two workers are required to complete each job. It has also been proven to
be highly effective at conducting longitudinal joint repairs.18
Cons
Infrared repairs are limited to the months in which hot-mix asphalt is in local production.
It may be possible to ship in hot mix from other regions, but shipping costs may be prohibitive.
(although this report found many Public Works who stockpile hot-mix asphalt in the fall, in order
to avoid using the temporary and highly-priced cold-mix asphalt). Infrared also takes longer than
throw-and-roll and spray injection methods, as the heating process typically lasts 5-10 minutes.
Infrared rays can only penetrate 2.5 inches below the surface of asphalt; therefore, infrared
machines cannot be used as a substitute for a full asphalt replacement (PPW’s cold-patch
recycling method is far more efficient for repairing entire stretches of road).
Sometimes when the existing asphalt of a repair site is too old (15-20 years since
creation), infrared heating can cause the brittle asphalt to crack. Those jobs can only be
permanently repaired by either total street reclamation or the semi-permanent method (a.k.a. cut
and saw).
Summary of Pros and Cons
Pros Cons
Requires only two laborers per patch team 5-10 minutes slower than existing methods
Extremely versatile (can be used for utility
cuts, settlement, cracks, bumps, low/high
spots, potholes, seam bonding, manhole cover
ramping, etc.)
Cannot penetrate farther than 2.5 inches below
surface point of asphalt
Lasts 14 times longer than throw-and-roll
methods
Not as effective for older asphalt (+15 years
since initial laying)
Seamless cracks Requires hot-mix asphalt
Low carbon footprint
Easy to use and to teach to existing workers
15 Note: This analysis did not include the cost of car damage that occurs when patch jobs fail, which would add more to the total
cost of using the throw-and-roll method. 16 Munir, Kim, & Abbas ibid., 29 17 Munir, Kim, & Abbas ibid., 78 18 Huang, Baoshan, Ph.D., P.E., and Xiang Shu, Ph.D. Evaluation of Longitudinal Joints of HMA Pavements in Tennessee. Rep.
no. RES 1304. Knoxville: Tennessee Department of Transportation, 2010. Print.
5
Substantially reduces amount of asphalt needed
per permanent repair
Highly recommended by other cities/counties
No milling or loud equipment required
Can also be used for longitudinal joint repair
Findings from Other Cities & Counties
East Lansing, MI: Cutting Costs on Asphalt Purchases
Over the years the price of cold patch in Michigan has steady increased from $60 per ton
to around $110 per ton. East Lancing’s Public Works could not afford this increase, so it decided
to look into asphalt saving techniques. Since infrared technology can mix previously used asphalt
in with the virgin asphalt inside the reclaimer, the method requires less asphalt per patch.
Luke Reynolds of Asphalt Solutions met with Homer Allen, Streets Supervisor for the
City. Reynolds did three demonstrations (a utility cut repair, an alligator crack repair, and an
existing patch job that was too high) with a KASI infrared machine. Allen remembered that
“those three jobs that would normally have used ten tons of cold patch cost us only two tons of
hot-mix. Now, it hasn’t been a year just yet, but I can tell you that after five-six months these
cuts are looking just as good as our normal method, while using eight tons less than you
normally would. And he only used three people for the whole job.”19
East Lancing PW has recently purchased a KASI infrared machine and is planning to use
it this coming winter.
Columbus, OH: Battling Winter Potholes with Infrared
After the previously mentioned ODOT/University of Ohio report was finished, the
infrared machine (Kasi Minutemen, a trailer-operated infrared device) was passed onto the
District 12 region (Greater Cleveland) of Ohio. District 1 uses the machine for year-round
highway pothole patches, doing repairs in the winter months by stockpiling 32 tons of hot-mix
asphalt in the fall. ODOT Highway Management Administrator Butch Huebner oversees the
operations of the infrared machine, and has positive remarks about the method and its practice.
“We’re very happy with our little machine. It’s very easy to teach to your workers, it can be used
large areas that need surface repairs, and it works well around castings.”
Huebner also noted the increased savings associated with using infrared. “Our old method
was spray injection, and although it was a bit quicker, the materials would cost a lot more.”20
19 Homer Allen, Phone Interview. August 8th, 2014. 20 Butch Heuber, Phone Interview. August 6th, 2014.
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Tallahassee, FL: “Flawless” Utility Cut Repairs
In the city of Tallahassee, between 250 – 400 utility cuts are done each month. Most of
these cuts are repaired by the utility companies themselves. If a utility company ever does a poor
job and leaves a crack or a bad edge, the city has to follow up and re-patch the cut themselves.
The old method of fixing these patch failures was to bring in more asphalt and redo the
job in its entirety. After purchasing an infrared machine, now Tallahassee Public Works can
simply heat up the surface and get a compactor to reroll the faults in question. Tallahassee Street
Supervisor Thomas J. Lewis noted that “[Infrared’s are] amazing with utility cuts. What we do is
check all the regular utility cuts, and if we see problems, we bring in the infrared and reseal it.
No tear up, no extra asphalt, no jackhammers necessary. No problem.”21
This saves the
Tallahassee Public Works time and money when it comes to coordinating repair efforts with
private utility companies.
Bartow County, GA: Less Trucks, Less Workers
Bartow County did not have a problem with pothole failures. Their operation struggled
with the number of labor hours devoted to each pothole repair. To repair a series of potholes, one
team would saw and cut a pothole out, and then move onto the next one while a team before
them would shovel and press the asphalt into the freshly cut hole. As Randy Gray, Road Director
for Bartow County explains, “even though the pothole was repaired and stayed in place, it took
several vehicles and lots of employees to perform the duties.”
To cut down on the man hours needed per pothole repair, Bartow decided to purchase an
infrared machine. Randy Gray continues: “The infrared truck allows us to perform basically the
same duties with one unit and [fewer] employees, thus saving us time and money.” Gray also
mentioned the efficiency of infrared machines in adjusting the height of pushed up or rutting
areas near intersections, in which sections of asphalt bulge above the normal street level. Now,
they simply “heat up and cut off the high areas, and then re-compact it to repair for an over
lay.”22
Fall River, MA: Hot-Mix Repairs all Year Round
In Massachusetts, cold-mix asphalt costs $20 more per ton than hot-mix asphalt, and is
ubiquitously known as a temporary repair. To the Public Works of Fall River, it made no sense
to purchase any cold patch. They decided to stockpile large quantities of hot-mix in the fall in
order to make permanent repairs year-round, and bought an infrared machine to make sure each
patch could last as long as possible.
21 Thomas J. Lewis, Phone Interview. August 8th, 2014. 22 Randy Gray. Email Interview. August 12th, 2014
7
The results were substantial: Public Works Director Kenneth Pacheco said that after
using infrared patching, the demand for road reclamation decreased by 50%. Pothole complaints
also fell significantly after the winter months. He went on to say, “I only have one infrared
machine and a hot mix box, but I could definitely use another machine. The only thing really
stopping me is man power.” He did, however, express some concern with productivity. “If we’re
on schedule, then we use infrared every time we make a pothole repair because it saves us down
the road. But, if we’re behind schedule, we sometimes have to switch to our old throw-and-roll
methods– because it’s a quicker patch job– in order to keep up.”23
He also pointed out that in the city code of Fall River, every utility cut that is done must
be repaired with infrared. “It’s the best method out there.” He concluded.
Policy Recommendations
There are two Infrared manufactures from which to consider purchasing an infrared
machine from: KM International and Kasi Infrared. These two companies were determined by
price comparisons, reviews, quantitative reports, popularity, and anecdotal evidence from
different Public Works supervisors across the country. Both companies sell hatchback infrared
machines, which can be attached to any sort of vehicle equipped with a 2x4 tow attachment.
This report recommends contacting to do a free demonstration for the street supervisors,
administrators, and laborers of the street maintenance division of the PPW. If they are impressed,
then they should consider purchasing a trailer-attached machine for a one-year trial period. After
the trial period is completed, Pittsburgh’s PW should make a decision on whether to keep using
the machine, expand the fleet, or sell it in a public auction.
If a machine is bought, a one-day training session must be given to all future operators of
the device. Infrared asphalt repair is contingent on following proper procedures and storing the
materials correctly. The machine should also combine the companies procedural
recommendations with the recommendations given by the Ohio University/ODOT joint report,
which goes into lengthy detail about the best possible practices (as determined by extensive
experimentation) when using an infrared machine.
Conclusion
The PPW is pressed for street maintenance funds, and having to re-repair patch jobs is
costly in the long run. Infrared technology creates long-lasting patches without substantially
cutting into the PPW budget. A typical tow-behind infrared machine costs between $18,000-
$70,000, and its’ operating costs are similar to our current methods. As we start to make more
permanent pothole patches to our streets, the initial capital investment will pay for itself (this is
without even accounting for the other asphalt repairs that the technology excels at such as utility
23 Kenneth Pacheco. Phone Interview. August 13th, 2014
8
cuts and crocodile cracks). Improving the overall efficiency of our street maintenance program
can go a long way towards fixing Pittsburgh’s damaged roads.
10
Source: Evaluation of Winter Pothole Patching Methods, Ohio University & ODOT Report
Notes on Step 3: Wait approximately 15 minutes for pavement to become 280 degree hot mix
again. Time varies by ambient temperature. Can be used in temperatures as cold as 10
degrees below zero. System emits true infrared rays, heating asphalt without burning or
oxidizing.
Notes on Step 10: Let restored area cool before opening up to traffic.
11
Local Infrared Repair Laws
Point Pleasant Beach, NJ
Ordinance 2012-26 InfraRed Patch Road Restoration Requirement
Adopted: June 26, 2012
AN ORDINANCE OF THE BOROUGH OF POINT PLEASANT BEACH,
COUNTY OF OCEAN, STATE OF NEW JERSEY, AMENDING AND SUPPLEMENTING
SECTION 14-1 OF THE BOROUGH CODE, ENTITLED “EXCAVATION AND
CONSTRUCTION IN PUBLIC STREETS” TO REQUIRE INFRARED PATCH DURING
ROAD RESTORATION.
BE IT ORDAINED by the Mayor and Council of the Borough of Point Pleasant Beach, County
of Ocean and State of New Jersey as follows:
SECTION 1: Chapter XIV of the Borough Code, entitled “Streets and Sidewalks” shall be
amended and supplemented at Section 14-1, entitled “Excavation and Construction in Public
Streets,” by deleting Section 14-1.11 in its entirety and replacing same with the following:
“14-1.11 Restoration of Surface.
The surface of all streets shall be restored by the applicant after 30 days settlement time or
appropriate mechanical compaction using six inches of Dense Graded Aggregate, four inches of
Hot Mix Asphalt (HMA) 19M64 Base Course and two inches of Hot Mix Asphalt (HMA)
9.5M64 Surface Course, as set forth in New Jersey Department of Transportation Standard
Specifications for Road and Bridge Construction. At the time the final surface restoration is
made the entire trench area plus one foot border of existing pavement to remain shall be heated
with an infrared heater and then the entire surface rolled to form a seamless repair over the
excavation area. The bond posted for compliance shall be released only after acceptance and
approval by the Borough Engineer of the municipality of the work completed and acceptance and
approval of the County of Ocean and State of New Jersey when appropriate.”
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Bloomingdale, NJ
ORDINANCE 14-2013
OF THE GOVERNING BODY
OF THE BOROUGH OF BLOOMINGALE
AN ORDINANCE OF THE BOROUGH OF BLOOMINGDALE, IN THE
COUNTY OF PASSAIC AND STATE OF NEW JERSEY, THE CODE OF THE
BOROUGH OF BLOOMINGDALE BY AMENDING CHAPTER XX,
“STREETS AND SIDEWALKS,” ARTICLE II, “STREETS,” CHAPTER 20-11,
“STREET OPENINGS AND EXCAVATIONS,” SECTION 20-11.16,
“RESTORATION,” TO REQUIRE INFRARED PAVEMENT RESTORATION
FOR ALL ROADS OPENED WITHIN FIVE YEARS OF PAVING
…
f. Any road that has been paved in the last five years shall be restored with infrared
pavement restoration for areas up to 50 square feet, as approved by the Borough Engineer. Areas
over 50 square feet shall be restored by milling and paving from curb-to-curb. The final scope
and depth shall be determined by the Borough Engineer.
Greenville County, SC
Section 18-66. Fee Schedule
The initial permit fee for all longitudinal and transverse installations within the road rights-of-
way shall
be required in the following amounts:
…
(c) Newly Paved Roads
If it becomes necessary to cut any road, which has been resurfaced within three years of the
permit application date, a fee of $335.00 shall apply for the first year, $235.00 for the second and
$135.00 for the third. Restoration of the cut shall entail compaction reports from a 3rd party geo-
technical firm confirming 95% compaction. The restoration patch shall be done using an infrared
paving process or an overlay of the entire roadway at the discretion of the County Engineer.
13
Randolph, ME
…
K. ‘Infrared Process’ shall mean the process of reheating an existing asphalt surface, adding
more Hot Mix Asphalt if needed, raking and rolling the material to remove the joint in the
asphalt surface
F. When an area to be repaved exceeds one hundred (100) square yards, an additional 12” of
pavement shall be milled at a depth of the required thickness of the surface pavement
surrounding the repair area. Resurfacing shall be accomplished using self-propelled paving
equipment complying with the latest MDOT and Town specifications. The Town may require the
surface of the new pavement to be infrared treated when completing permanent repairs. The
infrared or other approved process if required shall be performed not less than six (6) months or
more than twelve (12) months from the date of resurfacing.
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