Research Idea Details

Research Idea Scope

The proposed research
provides an innovative multi-disciplinary approach to cost-effective management
of storm water. DOTs needs effective tools to meet recently enacted federal
(EPA) regulations for reducing the amount of fine sediment generated from
highways. Infiltration is the most effective method of reducing fine sediment.
In place of impervious surfaces, pervious concrete pavement reduces runoff and
distributes infiltration. In addition, preliminary studies at the Western
Transportation Institute (WTI) has demonstrated the ground powder of cement
mortar or 100% fly ash mortar to effectively remove phosphorus from wastewater,
with removal rates in excess 94% at phosphorus concentration from 20 to 1000
mg/L (see Figure above). Further research is warranted to explore the
cost-effective use of cementitious materials for stormwater management.

This research project will
evaluate the feasibility, cost-effectiveness and benefits of using sustainable
cementitious materials for stormwater management by DOTs, either as replaceable
filters or as pervious concrete.

Fly ashes readily
available will be assessed and utilized. Fly ash will replace cement as binder
by at least 75% and up to 100%, without the need for activator (e.g., alkalis
or heat treatment). This technology takes the advantage of technical
breakthroughs found in the recent advances in the 100% fly ash concrete and in
the nano-/micro- modification of cementitious materials.

This research will address
key technical challenges associated with using fly ash concrete as replaceable
filters or as pervious concrete in the highway environment.

The proposed activities
are divided into four parts: (1) synthesizing high volume fly ash binder and
concrete, based on the survey of current practices, DOT user requirements, and
materials availability; (2) optimizing mix designs of fly ash concrete modified
with nano-/micro-materials, recycled concrete aggregate or demolition waste,
ordinary Portland cement, and other additives; (3) assessing the properties of
fly ash concrete as replaceable filters or as pervious concrete, and their
performance in treating simulated stormwater (total suspended solids, total
phosphorous, total nitrogen, and metals); and (4) assessing the
cost-effectiveness and benefits of such cementitious materials for highway
stormwater management, relative to current practice. 

Urgency and Payoff

This research is urgently
needed in light of the increasingly stringent environmental regulations related
to water quality. This research will greatly contribute to the DOT strategic
objectives, by improving the cost-effectiveness and sustainability of the
highway infrastructure and the efficiency of stormwater management. This work
is expected to produce substantial benefits for DOTs, MPOs, county and city
stakeholders, as well as agencies with similar climate, by understanding the
efficacy and appropriateness of pervious concrete pavement, a Low Impact
Development (LID) technology.

Pervious
concrete enables the use of space that is already part of the highway system
for stormwater runoff control, thus reducing the need for additional land.
Reducing the amount of impervious surfaces may reduce or prevent the need for
other stormwater management infrastructure (e.g., ponds, wetlands, and
vegetated swales and filter strips), by decreasing the volume, flow rate and
contaminant loading in stormwater runoff. Finally, this research will remove
fly ashes from waste stream and/or add value to its use in stormwater BMPs