Photo essay: Pouring the deck for the Fillmore/I-25 interchange's new south bridge
A layer of plastic-topped sheets was all that passersby could see the morning of
Aug. 5 atop the new Fillmore/I-25 south bridge.
Hidden as a result were the efforts of about 35 workers from project contractor
SEMA Construction, who had spent the night pouring and smoothing about 35
mixing truck's worth of cement onto the recently erected span over thousands of
pounds of criss-crossing rebar.
The sheets even hid their own usefulness, in that their undersides, the parts
touching the new cement, consisted of water-soaked burlap that's meant to keep
the cement from drying too quickly and adversely affecting its stability.
After about a week, the bags will come off, and roughly by September, project
officials expect that cars will be able to drive on the new surface.
The overnight job was the most recent milestone in the $15.1 million Fillmore
interchange replacement project. Construction started last February. Completion is
anticipated in the summer of 2016.
The deck pour required shutting down, for most of the night, the existing Fillmore
bridge as well as the interstate (although through traffic could bypass the project
area via the ramps). Crews had sealed the underside of the superstructure
beforehand, but the interstate had to close when the pour was above the travel
lanes. That's because 100 percent certainty does not exist in such jobs that no wet
cement will drip onto the roadway below.
Westside Pioneer Editor Kenyon Jordan took photos from about 10 p.m. to
midnight. Representative shots with captions appear below.
Note: Facts for this article came mainly from answers to on-site questions of Ted
Tjerandsen (pronounced CHAIR-and-sen) of Wilson & Company, the project
consultant for the Colorado Department of Transportation (CDOT).
To see the Pioneer's previous photo essay on the placing of the new girders
at Fillmore/I-25 July 12,
click this link.
Standing on the superstructure of the new
Fillmore/I-25 south bridge the night of Aug. 4, SEMA workers spread and smooth
the freshly poured cement, in conjunction with a concrete pumper and a
concrete-finishing screed. The pumper is the narrow, orangish-red equipment
rising up at left and coming down at right. Its fuller size can be seen in photos
below. Two pumpers were used in the project, one at either end of the bridge, with
long booms stretching across, and the cement pouring out of hoses that workers
could move around to direct the flow over the green-colored rebar. The pumpers
were connected to a series of cement mixers that arrived full and departed empty
(about 35 trucks in all) throughout the night. The screed, equipped with leveling
attachments controlled by an operator on top, is the large yellow device.
"Bidwell" is the name of the manufacturer. Weighing about 5 tons, the machine
spans the distance between the sides of the bridge. Earlier, crews had installed rails
on either side - allowing it to move along them the length of the bridge. A crane
then lifted the screed onto the rails the afternoon of Aug. 4. After that, the workers
went home to rest up for the overnight pour.
LEFT: A waning moon adds natural light to the
generator-driven illumination of the bridge project in an east-facing view Aug. 4,
shortly before midnight. RIGHT: Two SEMA workers direct the flow of cement
from the pumper.
Attached to a concrete pumper at right, one of
the roughly 35 cement mixers sits at the east end of the new south bridge as it is
emptied during the deck pour.
LEFT: In a west-looking view, workers next to
the yellow concrete-finishing screed spread and smooth cement for the new south
bridge. Walking along the old bridge (just to the north), an inspector watches the
RIGHT: It's hot work spreading cement on a bridge, but there's nowhere to get
hydrated. Standing on the old bridge, Josť Acuna of SEMA tosses a water bottle
across to a grateful co-worker.
Both concrete pumpers, one at either end of the
new south bridge rise into the night sky in this view from the east side of I-25. At
the time, only the east-side pumper was in use because the pour started from that
end. Midway through the night, when the westward-moving screed passed the
mid-point of the bridge, the pumper on the west began supplying the concrete.
Over an hour after the concrete was poured and
leveled, a SEMA employee sprays a special chemical substance that will help
"cure" the concrete to ensure a solid result. This is occurring as new cement
continues to be poured in front of the finishing screed (at right), which is moving
from east to west across the new bridge.
Mechanical equipment is invaluable on bridge
projects, but humans are too, as indicated by a worker stretching his smoothing
tool underneath the big yellow finishing screed and along the edge. This was a
common activity during the operation. Note at right another worker coming over
The next morning (Aug. 5), a SEMA crew
finishes the job of wetting the burlap on the underside of plastic-coated sheets and
placing them over the cement that was poured the night before. At this point, the
bridge cement is hard enough to walk on, but it will be two weeks or more before
it can be driven on. The sheets will be left on about a week, helping regulate the
Westside Pioneer article and photos
Would you like to respond to this article? The Westside
Pioneer welcomes letters at
(Click here for letter-writing criteria.)