If you get cement hot enough, it explodes.
I tried to use some of those cement (made of cement and sand) blocks they use to level trailer homes in a woodstove as a base.
Blew holes through the ceiling.
Concrete is made of sand, limestone dust, and gravel. The less gravel and more limestone dust, the easier it will explode. So, it is possible for it to explode, although I doubt the overpass/bridge exploded.
Yes, local news had videos of loud booms occurring, that’s when AFD pulled the fighters back, then it collapsed. Hartsfield Jackson Fire crews came and sprayed foam on the area.
And there is that too.....