Motorists who use Eaton
Road in St. Clair Township may be noticing some rather uncommon
road signs like "fiber mat," "SAMI,' and "glaspave."
Granted, these aren't your typical speed limit and stop ahead
signs but regular readers of the BCEO web site may already be
familiar with some of these terms which refer to various types
of roadway surface treatments. The signs, placed every 400 feet,
indicate six different pavement test sections currently being
applied to Eaton Road.
Butler County Engineer
Greg Wilkens plans to test some of the resurfacing methods which
have actually been used for many years, some as old as the paving
business itself. But in recent years new technologies have worked
their way into the standard tar and gravel and asphalt treatments.
With the rising costs of roadway paving Wilkens wants to formally
evaluate which methods work best for the money.
"We want to determine
what gives us the most bang for our buck," he said. "Standard
asphalt resurfacing has become so expensive in recent years that
we've gone back to chip seal in some cases. While not always
as attractive, it averages about $100,000 less per mile to use
chip seal versus standard asphalt." The cost to chip seal
is roughly $40,000 per mile as opposed to blacktopping which
averages $140,000 per mile.
"The old tar and
stone method, or chip seal, has been vastly improved with various
new technologies and we want to compare these on an even playing
surface," Wilkens explained. "While we've employed
these new chip seal methods on different roads, we'd like to
test each of them along the same stretch of road so we're comparing
apples to apples."
BCEO Construction Deputy
Randy Johnson concurs: "This way each treatment will be
applied at the same time on the same road with the same traffic
counts and snow blade passes. Snow plows and road salt in particular
take a toll on pavement. By putting all of these treatments in
the same section they'll be subjected to the same wear and tear,
allowing us to make a clearer assessment."
The Treatments
The Engineer's Office
is in the process of applying six surface pavement test sections
to Eaton Road between Brooks Road and Taylor School Road:
- Chip Seal - Traditional tar and gravel
mix. The tar is referred to as liquid AC, a composite mixture
of hot liquid asphalt and mineral aggregate. A coat of liquid
AC is applied to the roadway surface as a binder and then small
crushed stone chips are spread adhering to the hot liquid AC.
This is the least expensive method of resurfacing roads.
- Double Chip Seal - Two layers of chip seal.
The first layer usually contains larger stone while the second
utilizes smaller.
- Micro Surface - Similar to a process known
as slurry seal. Emulsion is always polymer modified and special
additives are used.
- SAMI Seal - Stress Absorbing Membrane
Interlayer. Similar to chip seal but the liquid AC contains different
polymers that affect the bonding to stone.
- Fiber Mat - Similar to chip seal but
the liquid AC contains fiberglass strands mixed in with the other
mineral aggregate.
- Blacktop - Standard asphalt. This is
traditionally considered the smoothest and nicest treatment but
is also the most expensive. The blacktop test section on Eaton
Road will contain two different under treatments: routine crack
seal and Glaspave, a fiberglass waterproofing paving mat
that is rolled out like a rug before the asphalt is applied.
Each section will be
inspected and documented quarterly. The Engineer's Office hopes
to evaluate the condition and life expectancy of each surface
treatment and determine which are the most cost-effective. "Obviously
our goal is to save taxpayers money while providing a smooth,
safe commute," Wilkens said. "We'll assess and compare
over the next one to five years and draw our conclusions. In
the meantime, we'll continue to explore new technologies that
we and the townships can use in an effort to stretch an increasingly
limited revenue base."
Wilkens noted that
higher fuel prices have translated into increased paving costs
since asphalt products, even in their simplest forms, are petroleum-based.
The BCEO typically does about a million dollars worth of road
resurfacing annually, but that amount doesn't buy as many miles
as it once did. That has prompted the BCEO's engineering team
to look at some of these advanced products and perform its own
engineering analyses such as the testing on Eaton Road.
# # #
For more information
contact:
Chris
Petrocy, BCEO Public Information Supervisor
Greg Wilkens, P.E., P.S.,
Butler County Engineer
Phone 513.867.5744 • Fax 513.867.5849
