25
*STTR
Project: Utilize Cementitious High
Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt
Pavement as Base Course—Bloom
Consultants, LLC, 10001 Innovation Drive, Suite 200, Milwaukee, WI
53226; 414-771-3390
Dr.
Haifang Wen, Principal Investigator, hwen@bloomconsultants.com
Mr.
Mathew P Tharaniyil, Business Official, mtharaniyil@bloomconsultants.com
DOE
Grant No. DE-FG02-05ER86238
Amount:
$749,567
Research
Institution
Board
of Regents of the University of Wisconsin
Madison,
WI
Because
of stringent environmental regulations, the power generation industry must take
measures to reduce the emission of nitrogen oxides (NOx), sulfur oxides (Sox),
and mercury (Hg). Low-NOx burners
reduce emissions by changing the combustion characteristics of coal boilers, but
they increase the amount of residual unburned carbon in the fly ash.
Increased carbon levels in fly ash make air-entrained concrete production
more difficult, because the activated carbon absorbs the desired air-entraining admixture in the concrete. As
a result, most high-carbon-content fly ash has to be landfilled, resulting in
significant land purchase costs and potential environmental issues.
This project will develop technology for using this fly ash
as a base course for asphalt pavements.
Unlike concrete, which needs air voids,
minimal air void content is preferred for the asphalt application.
In Phase I, laboratory tests were conducted to evaluate the
performance of recycled asphalt treated with cementitious high-carbon fly ash. The
test results indicated that the high-carbon fly ash could be used as a quality
base course material for asphalt pavement. In
Phase II, three test cells, each 500 feet long, will be built and subjected to
accelerated traffic loads to compare the performance of fly-ash-treated recycled
asphalt to that of conventional crushed aggregate, and to untreated
recycled asphalt pavement. An
economic analysis will be conducted to evaluate the cost-effectiveness of the
material.
Commercial Applications and other Benefits as
described by the awardee: The
technology offers the potential to use one hundred percent of the cementitous
high carbon fly ash that otherwise would be landfilled, eliminating the costs of
disposing and landfilling. Both
the power industry and the highway industry should benefit from significant
savings in cost and energy.