NYCRRson wrote:I suspected they would do that, blasting it out would probably be more expensive and just a wee bit dangerous in a built up area. They will probably do the same for both end foundations as well. Some of that old concrete is actually quite tough. And being a railroad bridge the concrete was probably not damaged to any great extent by road salt.
Concrete is a funny material, it continues to slowly get stronger for quite a while (years and years) after it is poured, but after 110 years that concrete is probably not getting much stronger.
It's possible that they'll have to break it up. There's a system whereby they can drill holes in the concrete and insert an expansive epoxy-like material. Its expansion is stronger than the concrete, so it will bust a crack. With enough holes, you can break up the biggest piece of concrete without any explosion.
If you know where to look around Western NY there are several old concrete RR bridge abutments that were just left in place to save the expense of removing them. Like the concrete coaling tower near the old Syracuse Enginehouse (haven't been there in a few years, I assume it's still there ?). They used to build stuff to last....
There are many abutments left in place, e.g. east of Pittsford or east of Newark.