First DIY concrete job - what went wrong

[GroundLoop]

Poured a ramp on the new shed I built. Much of the aggregate stayed on top even though I floated it more than a few times. I followed the directions on the bags and youtube (3 quarts of water per 80lb bag). I actually added about 4 quarts because with 3 it was still too dry. Looks to me like it still needed more water. It's just a ramp so I can get the lawn tractor in the shed. Not going to redo it, Just wanted to know for future reference.

 

[pop pop]

Can't see much in the pic, but did you trowel it?

 

[OzarkMan]

I use a concrete tamper to help knock down the aggregate before I trowel it.

 

[LXCam]

Not enough water so none of the creme got worked up. Next time grab a bag of cement and mix in one additional scoop of cement for each bag of pre-mix and don't over work it when it's wet. Tamp it, float it and wait. Being its a ramp, the little bit of creme you might have had could have just been troweled off the surface but that's just a guess off that one picture.

 

[GroundLoop]

Thanks all. That confirms my suspicion - not enough water. I used the 5000 psi stuff from the big "orange" store. So if there had been more water the aggregate would have been able to sink and the cement rise to the top. No matter how much I screeded it, the aggregate would never sink. Good info about the concrete tamper. Will have one next time. I was just scared of using too much water and having a weak result. Oh well, better results next time.

Thanks again!

 

[bullnerd]

"No matter how much I screeded it"

You did float it too right? Not just screed?

I think you mentioned you did, but then you said this and makes it sound like you didn't.

 

[James-W]

It may not be the greatest concrete job around, but it should work out OK for a ramp to the shed.

 

[couch67]

yep rougher might be better for a ramp anyway. Although you likely don't need to worry too much about it icing up in your area!

 

[Firebird 1]

Its very easy to use too much water with sacrete type mixes. Most diy'rs think it needs to be "watery" to work right. When mixed correctly it seems like its too dry, but it is really fine that way. Once you have it placed you need to use a magnesium float and work the surface. Not rocket science but it can be physically demanding. Looks ok to me but it needed a lot more "rubbing with the float". This will bring up "the cream" and fill in the voids. Not sure what you mean by a concrete tamper, but I have poured many thousands of yards of concrete and have never needed to tamp any of it.

 

[ForceFed70]

I'm also wondering if a trowel was used here? OP - you did trowel it right?
A tamper should not be required.

If it was indeed trowelled - your problem looks like either not enough water or you waited too long between adding water and pouring the slab (concrete had started to set).

 

[PWC Repair]

The bag mix has A LOT of aggregate in it. The more you stomp it, the smoother the surface becomes. You don't want to overdo it but you need to be able to float it out without rolling rock around on the surface. Next time you pour some, grab a 2x6 or brick and start patting the surface firmly and watch what happens.

 

[ard]

Just a funny story...

We had an old farmhouse in PA that we were remodelling. My dad invited a bunch of relatives- uncles, his dad, up to the house for a big concrete pour. I was a youngun, prolly 14 or so. We were doing two sets of steps, then 80 foot of walkway, and a pad in the basement for the washer and drier. (Basement was dirt, with stacked fieldstone walls...) First thing they did was run the chute into the basement window and fill those forms- 18" deep and 4x8 foot.

Then they dyed the rest of the load and poured the steps and walksways.

Lots of edging, floating, finsihing, brooming- what not. It was a long day, and as you all know 'concrete waits for no man'. We wrapped up the job just as mom announed dinner was ready. Everyone was sitting at the table, big italian meal ....when someone said: ******** basement!!!!

We'd forgotten to touch it after chuting in the concrete.

pick axes, a bit of water, much cursing....got it level and semi-smooth.

My sister lives in the house- washer and dryer still sit on that slab. 45 years later.

That ramp will be fine.

 

[Heavyspec46]

Sounds like something that would happen to me.

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