58 | CONCRETO & Construções | Ed. 93 | Jan – Mar • 2019
u
pesquisa e desenvolvimento
Sensors, intelligent structures
and smart digital concrete
1. INTRODUÇÃO
O
n September 30, 2006,
a highway overpass col-
lapsed in Laval, north of
Montreal, crushing two cars and
killing five people (Fig. 1). The col-
lapse occurred without any warn-
ing. The incident has brought a
number of issues to the forefront
as related to the overall safety of
our concrete infrastructure. This ill-
fated incident has created a nega-
tive impression of concrete bridges
in people’s minds, and the same
needs to be changed via a pru-
dent management of our concrete
bridges (and other structures) in
the future (Figs. 2-3).
Like Canada’s population, its in-
frastructure is also aging. Most of
it was built in the 1960s with rein-
forced concrete. Unfortunately, with
copious quantities of de-icing salts
applied to our bridges and roads to
prevent them from becoming icy and
slippery, corrosion of the reinforcing
steel within the body of concrete
has become a real problem. Corro-
sion produces rust, which occupies
about 20 times more volume than
steel itself and causes cracking and
spalling in concrete and sometimes
even collapse.
In Brazil, the infrastructure de-
terioration is equally alarming. The
World Economic Forum recently
ranks Brazil as 72nd out of 138
economies for adequate infrastruc-
ture. The same report ranked Mex-
ico at 57th. While we know that
the Brazilian economy has shrink
by more than 7% over the past two
years, the only way to move it up is
to provide infrastructure upgrades
and large mega projects.
Decades of uncontrolled corro-
sion of reinforcing steel and lack of
timely maintenance have now cre-
ated an infrastructure crisis or “back
log” in Canada—and, in fact, around
the world—of unprecedented pro-
portions. The Federation of Canadian
Municipalities estimates that major
Canadian cities face an infrastructure
deficit of approximately $200 billion
just to maintain the current infra-
structure, and worldwide the prob-
lem is pegged at nearly $900 billion.
Canada has nearly 60,000 bridges
and 10,000 parking garages that
require repair and/or strengthening,
and over 20% of these are in need
NEMKUMAR (NEMY) BANTHIA – P
rofessor
, D
istinguished
U
niversity
S
cholar
& C
anada
R
esearch
C
hair
in
I
nfrastructure
R
ehabilitation
/CEO
and
S
cientific
D
irector
T
he
U
niversity
of
B
ritish
C
olumbia
/ C
anada
I
ndia
R
esearch
C
enter
of
E
xcellence
(IC-IMPACTS)
u
Figure 1
The Concorde overpass collapse near Montreal in 2006
