Civil Engineering Research
Dr. Cosentino has received nearly $2.7 million in
funded research from 17 funded projects over 15 years in two succinct
areas of geotechnical engineering. The first focused on fiber-optic
sensors and their application to civil engineering measurements, and
the second concerned determining highway applications for various recycled
materials, including waste-to-energy ash, waste glass, recycled asphalt
pavement and scrap tires. His interdisciplinary skills have enabled
him to receive funding as the principal investigator on 13 national-
and state-level projects, while typically providing support for a half-dozen
graduate students each semester. Dr. Cosentino has consistently been
one of the top 10 researchers at Florida Tech. In 1993 Florida Tech's
College of Engineering recognized Dr. Cosentino's research with the "Outstanding
Research Award."
Project duration: 12 months
Funding: $115,229.00
In 1992, Florida Tech completed a study for the Florida
Department of Transportation (FDOT) on the evaluation of fiber optic
sensors for determining the variation of pore water pressure in soils.
Results indicated that an inexpensive prototype fiber optic sensor
could be used under either lab or field conditions. Beginning in 1994,
a three-phase traffic-sensor study was initiated, where fiber optic
sensors were developed and embedded in flexible and rigid pavements.
Approximately 50 fiber optic sensor systems were successfully deployed
at 5 traffic sites in Florida, between 1997 and 2000, by Florida Tech
researchers. Some of the world's first fiber optic traffic classification
and weigh-in-motion sensors were deployed as part of this research.
They have functioned under severe loading and climatic conditions since
installation (See Photo 1). Data from these sensors is currently
being taken and used by FDOT's Traffic Statistics Office.
Measuring pore water pressures in soils has always
been a formidable task. Fiber optic pore pressure sensors may prove
to be more accurate than the piezometers and more durable and economical
than the pore pressure transducers currently used for field monitoring.
These same sensors may also be useful in measuring total stresses. In
addition, they could be used in the laboratory to replace existing
pore pressure transducers. These fiber optic sensors would be
immune to electromagnetic interference and corrosion. A study
involving the refinement of the laboratory sensor for future use in
the field is requested.
FDOT will be able to record accurate real time in
situ pore water pressure measurements during and after construction. Fiber
optic sensors have advantages over other sensors because they are
immune to electromagnetic interference, rugged and relatively inexpensive,
with some optical fiber costing as little as 15 cents per meter.
Current status (Updated August 1, 2001): Several
types or models of circular sensors have been constructed out of relatively
inexpensive components (See Photo 2). One-model functions for pressures
up to 10 psi (70 kPa), while another functions for pressures up to
100 psi (700 kPa). They range in size from 1.25 to 2.5 inches in diameter
and are about 1/16th inch thick. They have 2 fiber
optic leads that can be made in any lengths.
Concrete Ready Mix Truck Actuating
Fiber Optic Traffic Sensors for Weigh-In-Motion Analysis at CSR Rinker
Plant, Palm Bay, Florida
Fiber Optic Pore Pressure Sensors
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Project length: 12 months
Funding: $267,505.00
Milling asphalt pavement (See Photo 1) is a common
pavement rehabilitation process, which produces large quantities of
Recycled Asphalt Pavement or RAP. A significant percentage of the RAP
is reused in new hot mix, however, with the stringent "SUPERPAVE" design
criteria set forth by the federal highway administration, the reuse
of RAP in new hot mix has decreased from nearly 50 to about 15 percent. This
reduction is producing a large surplus of RAP within Florida. It possesses
desirable engineering characteristics and should be an economical source
of fill for FDOT. It should be useable for example in highway embankments
or any areas outside the paved surface.
Current Status (Updated August 1, 2001): RAP
at the field site (See Photo 2) is being evaluated using all of the
latest field-testing technologies. Results from these tests are
being compared results from the conventional LBR testing. Mixtures
of RAP and Florida muck show that a strength increase occurs in RAP
mixed with 20 % muck. The mucks being studied contain fine sands and
silts. The early environmental field results show that RAP should
not pose any environmental threats.
Pavement Millings are an abundant
source for highway material
The RAP field site was developed
to allow the latest highway and environmental testing procedures
to be
implemented
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