The corruption amongst the ownership of concrete companies and the city's politicians has been an enduring feature of the local political landscape, not too long ago SDOT would only build roads out of concrete unless there was a very good engineering reason not to.
The impact of the concrete strikes here in Seattle has been awful tho, it caused multiple clients of mine to give up leases due to half complete projects impeding their ability to do business.
Hopefully in the future it won't take repeated protests over 5 years to reach a compromise contract. The concrete industry's management needs to be treated much more severely than what they got away with this past go around.