The work is aided by a moving steel structure in place across the bridge to smooth and grade the new surface.
That’s the latest word from Lynn Murphy, bridge project coordinator for the city of Clinton, who said large concrete pumps were put in place to move the wet concrete onto the bridge deck.
The bridge will require 3,400 cubic yards of the concrete mix for the deck, which we be nine inches thick, Murphy said. The average concrete truck carries just 10 cubic yards of the mix, he added.
Prior to the pouring of the concrete, the construction crews installed 1.5 million pounds of epoxy-coated steel rebar that will hold the concrete in place and reinforce it so it can handle the heavy traffic the new bridge will carry between downtown Clinton and South Clinton on U.S. 25W.
November is the 27th month of the three-year bridge construction project. The new bridge, expected to open late next summer, replaces Clinton’s iconic “Green Bridge,” officially named the Lewallen Bridge, which will be torn down and removed after the new span is opened to traffic.
Here are some excerpts from Murphy’s latest written report on the progress of the bridge’s construction:
“At month 27 of the 36-month project:
“Bridge Deck Drains -- Complete
“The installation of deck drains along the curbs and gutters is complete.
This will allow storm water to flow off the driving surface, into the gutters, and then drop vertically through the drainage structures.
“Epoxy Coated Steel Rebar - Complete
“The required 1.5 million pounds of epoxy-coated steel rebar is now installed….Once the bridge deck and sidewalk are in place, [the] vertical extensions will allow the concrete parapet wall to connect to the deck and sidewalk.
“Concrete Bridge Deck
“Concrete pouring should begin within two weeks. Photos show the preparation of a concrete screed device that extends across the entire width of the bridge deck. Notice that the screed structure rides on round steel pipe rails. The screed must be adjusted to precise tolerances so the finish grade of the new concrete surface will match the plan specifications. The screed rail will carry several attachments to perform different functions for pouring concrete.
“Once a large concrete pump is in place and begins to deliver the concrete mix, augers attached to the screed rail will move back and forth across the bridge deck width and will distribute the concrete. A vibrator attached to the screed rail will remove air voids.
“Concrete finishing floats and surface rollers will move across the screed rail and will smooth the concrete surface to the proper elevation.
“Lengths: The concrete bridge deck is 1,136 feet long.
“The approach to the new bridge, traveling northbound on Clinch Avenue from South Clinton adds a 463-foot length of new asphalt. This approach includes a painted median divider (11 feet wide on the approach, narrowing to eight feet wide on the bridge deck), which creates a safety buffer to separate opposing traffic.”
“North end, 102.3 feet This width includes two parapet walls, at 14 inches each; two sidewalks, at five feet, five inches each; two drain gutters, at two feet each; two bike lanes, at four feet each; and seven traffic lanes, at 11 feet each.
“South end: 77.3 feet.
“This width includes two parapet walls, at 14 inches each; two sidewalks, at five feet, five inches each; two drain gutters, at two feet each, two bike lanes, at four feet each; four traffic lanes, at 11 feet each; and one painted median divider, at eight feet wide.”
The bridge construction is expected to be finished by Aug. 31, 2021.