A two-direction bridge has four spans in one direction suddenly collapsed during construction. Each span appears to comprise of 6 precast RC I-beams likely to have been prestressed to be installed in simply supported condition. Apparently most of the beams were in place but a removable steel...
The above photo was from a youtube video showing the reinforced concrete supporting structure of the SpaceX rocket before and after the yesterday's launch when it exploded 4 minutes into the flight.
It appears the RC slab was flush as one level prior to the launch but now has the ground beams...
Here is the worst case of chloride attack to concrete I have come across in my professional life. I was not involved in its investigation but was surprised by structure's condition. The information may be useful to others.
The location is Middle East. The concrete structure is a box culvert...
