engineers question?

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The Chesapeake Bay Bridge east bound was built in the 50s- and is about four and a half miles long. Unfortunately back in August a tractor trailer went over the side and the driver lost his life. He tore out a section of the side wall which is reinforced concrete. The bridge people quickly made a repair and then inspected the sidewalls of the bridge saying it was ok. then after a more thorough inspection which immediately followed they decided the rebar inside the concrete had deteriorated and immediately began making further repairs. Now comes my question: the side walls are concrete and look much like jersey walls. Heavy metal angle plates were bolted to the sidewalls and the deck apparently tieing them together, then a guard rail was bolted to the side wall running horizontally down the middle. The concrete walls appear to have had expansion joints as the deck does but now this rail ties all that together. What happens during weather changes if these walls cannot expand and contract?