Just realized how much faster I got on flatwork after switching my mix design

I've been pouring driveways and patios for about 8 years now, mostly residential stuff around Portland. Last spring I had a garage floor that was 500 square feet and it took me and my partner almost 6 hours to finish and bullfloat the whole thing. This fall I did a similar size job, about 480 square feet, and we knocked it out in just over 3 hours flat. The only thing I changed was bumping up the fine aggregate a little and dropping the water-cement ratio by about 5 percent. The cream came up way faster and the troweling was way smoother without fighting bleed water all day. Has anyone else seen a big time difference just from tweaking their mix a bit?

2 comments

2 Comments

amy_coleman2124d ago

I saw a study from some university back east that looked at that exact water-cement ratio change. They found dropping it by just 5 percent cut finishing time by almost half on slab work. The bleed water thing is the real killer, especially when you're trying to get a decent float before the sun bakes it. A buddy of mine swears by adding a little extra fines too, says it makes the cream come up like butter. Sounds like you stumbled onto the same trick.

wesley38524d ago

Half the finishing time? That sounds like one of those numbers that only works in a lab. I've been around enough jobsites to know that real world conditions usually mess up those perfect numbers. But I've seen a similar thing on some big box store floors where the mix was tight and the finishers got done way faster than normal. The bleed water drying up before you can get on it is the real headache though, especially when the weather decides to cooperate.