Caltrans officials say they have completed repairs on the Richmond-San Rafael Bridge. The work began in February after a chunk of concrete fell and hit a car on the lower deck of the span, closing the bridge for most of the day. Crews replaced 31 joints that were upwards of 60 years old. The new joints have rubberized seals that shrink and expand based on temperature and are designed to prevent any more cracking of the concrete deck. While the joints have been fixed, Caltrans still has work to do on the 63-year-old bridge. Workers still need to straighten a section of the steel truss that was damaged by a big truck. That will mean nightly lane closures in both directions over the next few weeks.