PROJECTS

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FEMA Article
Disney Article
Aggregates and Roadbuilding Magazine Article
Reports & Data Testing

-FEMA-

H.I.P. has teamed up with FEMA in an effort to support emergency agencies wherever needed.
When Hurricane Charley hit southern Florida, H.I.P. saw an opportunity to make a significant contribution to the relief effort by
transporting and servicing the hundreds of generators needed by FEMA and the several emergency agencies deployed to aid the
devastated residents of Punta Gorda, Port Charlotte, and the many other communities ravaged by Charley. When Hurricanes
Frances and Ivan followed suit, H.I.P. continued to team up with FEMA in support roles.

Innovative repaving process is ‘HIP’ to Environmentality

-DISNEY-

Facility Asset Management has contracted a Florida-based company to USC environmentally friendly technology to repave Walt
Disney World parking lots. This unique process is faster than conventional paving operations, is 90 percent cleaner in emissions,
and uses 95 percent less gravel and 75 percent less petroleum. Crupi-Hot-In-Place Paving, or HIP Paving, repaves parking lots,
roads and runways using 100 percent of the existing asphalt. Traditional repaving processes use equipment and trucks to tear up
existing surfaces and carry the material to an asphalt plant, where machines mix about 25 percent of the material with rocks to
create new asphalt to be trucked back to the site for pouring and processing. HIP Paving accomplishes all of these steps on the
jobsite using a small train of moveable equipment. Two units heat the pavement to make it pliable, and a third unit applies more
heat and mills out the top two inches of pavement. That milled material then goes into a main mill to be mixed with a recycled,
oil-based rejuvenating agent, and an onsite lab tests the mix to ensure quality. Finally, the train lays the recycled asphalt. and
steel rollers press it into the required road shape. The train can process 15 feet of asphalt a minute, and vehicles may travel on
the finished surface within 30 minutes of paving. Dennis Young, Program Manager at Facility Asset Management, said cost savings
are just part of the overall benefit of the process. “The benefits to our company are many,” Dennis said. “It’s a quicker operation
HIP Paving makes one pass It’s really all done that day except for striping the surface. “The Environmentality aspect is that we’re
using the same asphalt on the pavement itself. We don’t have a lot of trucks bringing asphalt to the site, so that eliminates traffic
and emissions. We also eliminate the traditional tire tracks, which can be a Guest-show issue.” Crews recently used the HIP
Paving process to repave lots at the Magic Kingdom Park, and leaders are exploring additional opportunities.

Reprinted with permission from Disney's publication "Eyes and Ears", April 15-28, 2004. Story by Steve Langlois

-Hot-In-Place recycling gaining acceptance in Canada-

More provincial and municipal public works agencies are turning to insitu recycling as an alternative to conventional hot mix
asphalt pavement rehabilitation. Insitu recycling can be performed by both hot inplace (HIR) and cold inplace (CIR) asphalt
recycling methods, with both methods proving to be economical, conserving both energy and materials, and resulting in zero
waste.

CIR and fulldepth reconstruction are now routinely used in most regions of Canada to restore surfaces and stabilize roadways.
These methods include a final overlay of new hot mix asphalt (in Canada) which increases the overall cost. Candidate projects for
CIR and fulldepth reconstruction would be a pavement requiring rehabilitation due to severe distress. HIR is a costefficient
alternative pavement construction technology which involves the heating and mixing of the existing surface asphalt, remixing it
with or without admixture (a heated mixture of aggregates and asphalt cement binder) and binder rejuvenators, followed by
repaving — all in a continuous process.

In its Guideline Specifications for Hot inPlace Recycling, the Asphalt Recycling and Reclaiming Association, headquartered in
Annapolis, Maryland, describes HIR as an onsite, inplace method that rehabilitates deteriorated bituminous pavements and
thereby minimizes the use of new materials.

According to the ARRA, "HIR provides a lowcost maintenance strategy that enables the public works official to effectively reuse
existing materials. It also effectively addresses the classic symptoms of deteriorated pavement as cracks are interrupted and
filled, ruts and holes are filled, shoves and bumps are levelled and drainage and crowns are reestablished.

In addition, flexibility is restored by chemically rejuvenating the aged and brittle pavement, aggregate gradation and asphalt
content may be modified by some variations of this process. Highway safety is also enhanced through improved skid resistance,
while roadway deterioration can be suspended, pavements preserved and upgraded, and costly reconstruction avoided."

HIR technology has been found to be an economical and practical solution for the rehabilitation of existing surface courses to
depths of 50 mm or more by reducing the haul of materials, reducing usage of virgin aggregates and asphalt, as well reducing the
quantity of work to the travel lanes only. HIR restores the ride quality and surface condition of structurally sound pavements
while maintaining curb heights for safety and drainage.

Candidate projects have structurally sound pavements with surface condition distress and include pavements where traffic
volumes are not a factor. Pavements with significant quantities of patching or crack sealer, or those with extensive reflective
cracking, may not be suitable for HIR.

Local residential streets exhibiting severe surface distresses have been successfully rehabilitated using HIR to recycle all the
bitumenbound materials. HIR has also been employed to effectively eliminate moderate surface distress for highways and
arterial roads with significant traffic loading.

Roads with few severe structural distresses can be renewed by carrying out local subsurface repairs prior to HIR recycling of the
surface course. HIR has been applied as a wearing surface, integral overlays [where HIR material receives a surface overlay of
new asphalt], cold milling of the existing pavement followed by HIR plus overlay, or as an interim rehabilitation treatment. Since
the mid1990s, advanced HIR equipment and mix design procedures have enabled the production of final surface courses of
recycled hot mixed asphalt which meet stringent Superpave specifications under rigorous QA/QC procedures. These advanced
HIR methods eliminate the need for overlays of new plant mixed asphalt, and therefore have the potential to reduce the overall
surface rehabilitation cost by up to 40 per cent, when compared to other methods such as cold milling and CIR.

From a global perspective, much of the recent HIR innovation has occurred in Canada where transportation departments have
embraced the concept and equipment manufacturers have provided numerous improvements. In terms of equipment, HIR
technology has evolved from heated scarification through onestage to multistage HIR systems that include one or more
preheater units, one or more heater/milling units and remixer/paver combination units.

The overall HIR process is carried out by a train of equipment that heats the existing pavement to a depth of 50 mm or more,
mills or scarifies the hot asphalt surface, then adds rejuvenator oil and additional asphalt as required. The recycled materials
and beneficiating agents are then remixed, reprofiled and compacted in a continuous operation.

Modern HIR machinery and technology are the product of a series of ongoing improvements on the first primitive heater
scarification system developed by a Utah contractor in the 1930s.

Since the mid1970s, several manufacturers have developed equipment with variations in details and approach, but similar in
general features.

One or more infraredtype preheater units heat and soften the pavement ahead of the milling and recycling machinery. Some
manufacturers utilize stationary tines or teeth to scarify the warm pavement, but most currently use rotary milling methods. The
milling drums are similar to those used for cold milling, but require much less power because the heated pavement is soft.

Most systems mill to a depth of between 25 and 50 mm, with forward speed normally limited by the time taken for sufficient heat
to diffuse into the asphalt. Improvements made to the remixing and repaving process in the mid1980s included the introduction
of multistage systems to progressively preheat, hot mill, remix and pave the asphalt. Most manufacturers, including R W.
Blacktop, Wirtgen and Taisei Rotec, employed a single pass milling operation to remove hot asphalt to the desired depth. Twostep
and fourstep milling processes were subsequently developed by two Canadian manufacturers, Pyrotech and Artec, to improve the
efficiency and depth of milling. Pyrotech also developed an afterburner system to incinerate excessive smoke and vapours
generated by the infrared heaters.

In 1994, Martec Recycling Corp., Vancouver, B.C., introduced a new recycling system called the AR 2000 Super Recycler. Key
improvements incorporated into this new train include a heating system combining hot air and lowlevel radiant energy, diesel
fuel for both heating and motive power on all units, a recirculating hot air system to incinerate airborne emissions, a system for
the postheating, stirring and drying of the loosened asphalt, as well as a twinshaft pugmill for final mixing of recycled asphalt,
admix material and the rejuvenating agent.

To assess the overall suitability of a pavement for HIR, factors such as pavement depth and type, traffic volume, previous
maintenance work, and the pavement’s existing condition all have to be considered. Any resurfacing project selected for straight
overlay, or mill and fill paving, is a possible candidate for the new HIR process with the potential for considerable cost savings,
provided traffic volume is not an issue. Pavements exhibiting binder aging and map cracking are also suitable candidates, as are
pavements exhibiting surface distresses such as ravelling, coarse aggregate loss, and slight to moderate cracking.

The hot air HIR process can treat existing pavements to a maximum depth of 50 mm or deeper in certain cases, while all HIR
systems can typically correct crossfall deficiencies up to plus or minus 1.3 per cent, when milled to a depth of 50 mm and 15 per
cent beneficiating hot mix is added.

HIR minimizes traffic disruptions as vehicles can drive on the recycled mat shortly after compaction and need only be detoured
around the recycling train as it proceeds down the highway.

HIR recycling will not mitigate deepseated reflection cracking below the binder course or correct any major structural distresses.
Other situations which may not be suitable for HIR include pavements with large quantities of cold mix patches, spray patching or
chipseal surfaces, which may require removal prior to HIR, otherwise the HIR process can generate excessive smoke when the
heating units pass over large areas of patching material, especially when infrared heaters are involved.

Hot mix asphalt containing steel slag or crumb rubber may not be suitable for HIR due to poor heat transfer properties.

Projects are normally carried out in warm dry weather, with highest productivity therefore achieved during the summer months.

Overall, the advantages of insitu recycling include the conservation of aggregates, asphalt cement and energy. Insitu recycling
uses 100 per cent of the reclaimed material, while conventional central plant recycling is limited to much smaller percentages of
RAP. The newer HIR equipment, in conjunction with Superpave binder design of the recycled mix and appropriate QA/QC
procedures, will produce high quality surface asphalt with a similar lifecycle performance to virgin hot mix at significant cost
saving.

Future trends in HIR are focusing on not only mechanical placement systems but on advanced mix designs that will improve
longterm pavement durability and performance.

By Robert L. Consedine, Editor

Andy Bateman, Engineering Editor

Aggregates and Roadbuilding Magazine
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