Return to index: [Subject] [Thread] [Date] [Author]

Fly ash in concrete

[Subject Prev][Subject Next][Thread Prev][Thread Next] Has anyone had negative experiences with using fly ash in concrete mixes?

I'm working with an architect who doesn't want it used, but I'm not sure why.
 The spec's call for 3,500 psi 28 day strength concrete.  Fly ash is not
mentioned in the spec's, but a contractor has asked if it's permissible to
add it to the mix.  I understand that fly ash is used to improve flowability
of dry mixes.  I couldn't find much other information regarding the use of
fly ash in ACI 318 or any of my materials and concrete references.

The application for the concrete in question is spread footings for steel
columns and perimeter footings for slab/brick masonry support for a 2-story


David Williams, P.E.
Snyder Engineering, Inc.
Columbia, MO