Loading…
7
Wait, fly ash actually makes concrete stronger? Nobody told me this for 8 years
I was reading an ACI spec packet on a commercial job in Phoenix and stumbled on a section saying fly ash can boost long term compressive strength past 56 days. My whole career I thought it was just a cheap Portland substitute that slowed set time. I asked my foreman and he said yeah, 20% replacement is common for durability. But I've also seen fly ash batches that never reached design strength because the mix design was off. That's a big swing between saving money and failing a core test. Anyone else have a fly ash job that surprised them, good or bad? Or am I the last guy learning this?
1 comments
Log in to join the discussion
Log In1 Comment
alice26911d ago
Welcome to the club, I've been pouring concrete for 12 years and just found out last spring (guess I was too busy staring at my slump cone to read a spec book). The 56 day thing is real though, my last pour hit like 15% over design at 90 days with 25% ash. Bad mixes are a whole other animal, had one batch that sat there like peanut butter and we knew we were in trouble.
4