44
Geotechnical News March 2011
ASFE NEWS
FE’s Peer Review program. In 1999,
Engineering News-Record
magazine
named Peer Review one of the 125
most significant construction indus-
try innovations of the prior 125 years.
ASFE was the only association so hon-
ored.
We DO Get Respect
How do geoprofessionals demonstrate
that their services – “even” CoMET
services – are not commodities and
that geoprofessionals should be invited
to sit at “the table” from project start
to finish? First of all, you have to
demonstrate your worth to yourself, so
you believe in you. Second, you need to
tell others what you’ve told yourself…
and one of the best ways of doing that
was demonstrated by ASFE-Member
Firm
TTL, Inc
.
in the October 26
issue of
The Tennessean
(formerly
The
Nashville Tennessean
), with circulation
of 300,000 and readership of 600,000
or so. Headlined with…
Music City Center contractor
makes sure
concrete is fit for project.
Material must meet rigorous
criteria.
The article (written byAnitaWadhwani)
had the following to impart:
While hundreds of workers labor
downtown to erect the concrete
frame for the new Music City Cen-
ter convention center, one man in a
South Nashville warehouse stands
ready to tear pieces of it apart.
Rich Mote collects foot-long cylin-
ders of solid concrete siphoned from
the site. One at a time, in the dusty
room he calls his lab, Mote inserts
the concrete into a viselike machine
capable of inflicting a half a million
pounds of pressure. Then he waits
until he hears a loud crack — like
the sound of a baseball making
perfect contact with a wooden bat.
“See how it gets busted up,” said
Mote, an expert in the way concrete
crumbles, as he carefully unrolled
the broken cylinder from a leather
cover used to keep it intact while in
the machine. “That’s a good break.”
Mote is a group leader with TTL,
the Nashville geotechnical engi-
neering company that has a $1.5
million contract to do ongoing test-
ing of the Music City Center site
and its foundation. The daily testing
that goes on at its Antioch ware-
house ensures that, for each aspect
of the project, the concrete is mixed
to contract specifications, which can
vary significantly according to the
function the concrete provides and
the season, according to TTL Vice
President and Geotechnical Group
Leader Dan Terranova. “Everyone
thinks concrete is just a regular
commodity,” Mote said. “It’s not.
It’s a chemical, and there’s lots of
chemistry involved. We make sure
it’s the right thickness, the right den-
sity.”
Purposes Differ
Some concrete is required to have
a density that can support 7,000
pounds of weight per square inch.
That includes certain beams in the
convention center exhibition hall,
for example, that have to bear the
entire weight of the building. Other
concrete mixes serve different pur-
poses.
One of the convention center’s sig-
nature features is a perfectly smooth
concrete showroom floor, uncov-
ered by any carpet or other flooring.
That’s required to have a weight-
bearing capacity of 4,000 pounds
per square inch, Terranova said. The
concrete for the floor also is mixed
for a winter climate, even though
pouring began in Nashville’s unsea-
sonably warm October. That had to
be tested as well, Terranova said.
Disaster Prevention
The ongoing testing is critical to
avoid a catastrophic building disas-
ter or near-disaster, even years later.
In July, for example, the elderly res-
idents of a 15-story condominium in
Sarasota, Fla., were given an hour to
evacuate their homes after engineers
found design flaws in the original
36-year-old concrete pour. Resi-
dents haven’t been allowed to return
yet. Last year, in Houston, a newly
built high-rise condominium had
to be torn down shortly after it was
constructed when it sunk a foot into
the ground, a result of geotechnical
flaws that Terranova said could have
been avoided with proper testing.
TTL has been on-site at the $585
million Music City Center, Nash-
ville’s most expensive public proj-
ect, since before ground was broken
in March. The company sends sam-
plers, who take cylindrical molds of
every concrete pour, which is being
laid at a rate of 700 cubic yards per
day. Company workers average five
cylinder samples for every 50 to 75
yards of concrete poured, Terranova
said.
Mote crushes about 40 or 50 sam-
ples a day, a total of about 2,300
tests from the site thus far. He crush-
es them three days, seven days and
28 days after the samples are col-
lected. Until test day, they’re stored
in a humidity-controlled room in
an Antioch warehouse designed to
mimic downtown weather condi-
tions. No significant repours have
been required at the actual conven-
tion center site.
Could you get that kind of cover-
age? Yes, but only if you try. And when
you succeed, you will provide a huge
benefit for yourself, your firm, and the
geoprofessions. In short, think globally
and act locally. When you do, great
things can happen.
