NOTE
SUBJECT:
Consultation
with
Ottawa
County,
Oklahoma
County
Commissioners
TO:
File
FROM:
Stephen
Hoffman
DATE:
2/
27/
06
The
purpose
of
this
note
is
to
document
consultation
with
the
Ottawa
County,
Oklahoma
County
Commissioners.
Oklahoma
DOT
staff
indicated
that
Ottawa
County
had
considerable
experience
in
the
use
of
chat
in
pavement.
On
September
26,
2005
I
called
Mr.
John
Clarke
who
has
sat
on
the
County
Road
commission
since
1985.
I
briefly
explained
the
nature
and
scope
of
the
proposed
rule.
Mr
Clarke
noted
that
chat
had
been
used
as
an
aggregate
substitute
30­
40
years
ago
but
had
not
been
used
in
concrete
for
some
time.
He
also
stated
that
chat
used
in
concrete
would
probably
have
to
be
screened,
while
unscreened
material
has
been
used
in
hot
mix
asphalt.
He
noted
that
chat
is
currently
used
in
hot
mix
asphalt
and
has
been
used
between
25­
50
percent
of
the
aggregate
in
hot
mix
asphalts
with
good
results.
Mr.
Clarke
noted
that
chat
is
very
insoluble
and
holds
us
well
to
wear.
Chat
was
used
as
a
deicing
material
fro
many
years
throughout
the
county
but
that
practice
stopped
approximately
4­
5
years
ago.
Mr.
Clarke
noted
that
the
University
of
Oklahoma
was
conducting
an
air
and
runoff
monitoring
program
at
roads
that
had
used
chat
along
the
East
30
Road
between
South
530
and
South
550.
Results
of
this
monitoring
may
be
available
within
a
year.
