21A Stone No Fines?

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Old 11-25-17, 05:49 PM
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21A Stone No Fines?

Is 21A stone available with no fines? From what I read, yoy do not want fines when using 21A as a base for a concrete driveway because it inhibits drainage. Is this true?
 
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Old 11-25-17, 11:14 PM
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Why would you use driveway mix that compacts? I would think something like 3/4 crushed stone (described and used as a roadway or driveway "base") would be more appropriate? Why not ask the stone supply yard? Or do they not know their jobs either?
 
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Old 11-26-17, 03:39 AM
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21A without the dust and fines is not 21A crusher run. It's the fines that help define it as 21A. Crusher run can be a very good base but it will require proper mechanical compaction before you can pour a slab on top. If you want something with drainage you should consider something more like #57 which is clean 3/4" stones.
 
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Old 11-26-17, 05:23 AM
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21A is what the county and VDOT call for for the base of the curb, gutter, and apron, so I'm assuming they will use the same for the driveway. Their plate compactor wouldn't start when they were here last, and I wouldn't put it past them to not compact it if a cement truck was sitting there waiting. You think they would stop everything, waste a load of concrete, and go get another compactor? Hell no they wouldn't. They would pour anyway. Let's not be naive. The majority of things in residential construction are done improperly due to incompetence or plain old carelessness. What average homeowner is going to know whether the base was doe properly? 1 in 10. I'm in that 10%. I shouldn't be made to feel like I'm in the wrong for asking these questions and pointing out what contractors are doing incorrectly.
 
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Old 11-26-17, 06:01 AM
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Your naive if you think any builder would turn away a concrete truck once it got to the job. When the concrete truck leaves the plant you/he becomes liable for the cost. It's not like they can take the concrete back and deliver it at a later date. The only way to insure the gravel is compacted to your liking is to have that done BEFORE the concrete is ordered/sent!
 
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Old 11-26-17, 11:49 AM
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The only way to insure the gravel is compacted to your liking is to have that done BEFORE the concrete is ordered/sent!
That's the only way I've ever seen it done. Driveways, parking lots, roads, etc. Might be a couple of days between the compacting and the 'crete, as long as the weather is good.
 
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Old 11-26-17, 11:52 AM
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I used to paint for a builder who built high end houses but some of his practices were ludicrous. I've seen him backfill and pour concrete in the same morning
 
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Old 11-26-17, 02:52 PM
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Stuff like that is why clean stone like #57 is often required by code officials underneath slabs and footings. It naturally sits at a pretty high compaction rate so it's harder to screw-up.
 
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Old 11-26-17, 07:07 PM
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I agree things shouldn't be done on the same day, because they rush things and they don't get done properly.

Your naive if you think any builder would turn away a concrete truck once it got to the job. When the concrete truck leaves the plant you/he becomes liable for the cost. It's not like they can take the concrete back and deliver it at a later date. The only way to insure the gravel is compacted to your liking is to have that done BEFORE the concrete is ordered/sent!
Of course they wouldn't turn the truck away...that was my point (think you misinterpreted what I said ). I'v had to tell them to prep/form one day and pour the next, but they always seem to want to do everything in one day. Not going to happen this time because the apron, gutter, and curb forms need to be inspected by VDOT and this can't happen until I call it in.
 
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Old 11-26-17, 07:13 PM
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BTW, they rushed things with the foundation walls and the guys were still bracing the forms when the trucks showed up. The pumper sat there for at least 45 minutes, and this was after a 45 minute drive on an 85+ degree day. The concrete looked way too stiff to me, but of course they carried on. Once the forms came off, there were several holes and areas they had to patch by hand. And I also have small voids all over the wall, presumably because the mix was likely bad and/or because they didn't use a vibrator. I'm pretty pissed about this. It was painted white yesterday and the voids stand out even more now. I'm hoping there is some sort of sealer that can be brushed on that is thick enough to fill the voids and seal them so they don't break open even more (I van pick at some with my finger and they break apart)
 
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