The new I-85 bridge: Step by step

Rebuilding a bridge might seem as simple as snapping the pieces together like an oversized Lego set. But it’s far more complicated. Since I-85 in Buckhead collapsed March 30, dozens of C.W. Matthews employees have worked 24 hours a day to demolish the old bridge and build the new one. State inspectors have been at their side, checking their work. Here’s a look at the bridge construction step by step.

Credit: Richard Watkins

Credit: Richard Watkins

The foundation and 13 columns supporting the original bridge were still usable. The first step in building the new bridge was shoring up those original columns with more steel and concrete.

Next, workers placed reinforced concrete caps over the columns to support 61 concrete beams.

The beams – each weighing about 80,000 pounds – were laid on the caps and tied together for stability.

Credit: Richard Watkins

Metal forms were placed over the beams to hold the concrete of the bridge deck. C.W. Matthews then poured the concrete decks of the six bridge spans under construction. After the decks were poured, they were tested for smoothness and ground down if necessary. Then they were grooved to prevent them from becoming slick when it rains.

Finally, workers poured the concrete barrier walls on each side of the bridge deck and striped the new highway.

» ROAD TO RECOVERY: Rebuilding I-85 bridge a complex process

» IN-DEPTH: Is MARTA ready for its close-up after bridge collapse?

» EXCLUSIVE: Who’s to blame for the I-85 collapse?

» COMMUTING: MARTA adds parking spaces