OT: water and concrete pre-mix

what is the optimum amount of water I can use for 90lbs of pre-mix concrete? I will be mixing this in a wheelbarrow.It is for a stoop outside a door.Any and all suggestions will be greatly appreciated. thanks in advance. CC

Most pre-mixed bags of concrete or masonry products will have the optimum amount of water needed for that mix printed right on the bag.

Be aware that the cement can settle out during trucking.

It should be right on the bag, just add what they call for and you won't have any trouble with the water/cement ratio, the mix will be as strong as what it states on the bag.

This is not rocket science, so don't over analyze your job.

You will need a large industrial duty wheelbarrow to mix the whole bag at once. If you have a garden variety, do it in two batches.

A garden hoe is my preferred tool to mix concrete with in a wheelbarrow. Add water a couple quarts at a time as you mix. Don't let the mix get soupy - if all the dry aggregate is wet, just a little more water will be enough.

After its in the form, rap the outside of the form with a hammer to assure the concrete is smooth against the form. Do this twice as much as you think is necessary.

Don't over trowel the surface if you're going for smooth. If you want a non-skid surface, use a coarse broom about 45 minutes after you've screed it off.

Charles,
It takes very little water to hydrate the cement paste in a concrete mix. Use just enough water to make the concrete workable for your project.
In hot weather, it is important that the concrete does not dry out before it sets. Dampen the forms/soil before you pour and keep the concrete covered with damp burlap or canvas and plastic sheeting for at least 24 hours after you finish.
“1 – 2 -3” is the old saw for homemade concrete: 1 measure of Portland cement; 2 measures of clean sand and 3 measures of clean gravel. It is very important to use clean sand, gravel and water.

Good luck with your project,

Art

Good advice so far. Don't know your brand but quikrete 80# bags call for 6 to 9 pints of water trying to do it with 6 if possible. Don't dump your 6 pints in the wheelbarrow at once or it will take more hand hoeing to mix it. Mix what you can with a couple pints, rake in some dry stuff, and try another couple pints, repeat. That last bit of dry stuff is always hard to get mixed. Avoid a soupy mix. You didn't tell us what you are doing but too wet of a mix actually makes it harder to trowel smooth and may leave the surface pebbly with the water dries off the top. You probably aren't to worried about compressive strength for a one bag job in the garden or sidewalk repair.

I've screeded and floated small jobs with a short piece of smooth 2x4. Then edged it. You can do a first troweling/smoothing after the water sheen dries off. Do your brush finish at this time if that is what you want. After it is dry enough you can't indent it with your thumb, do your final troweling for a very smooth finish. It takes pressure and if you can't get it smooth, keep a container of water handy and dip your fingers in it and flick it on the dry spot to help the hard troweling but don't over do the water.

I've mixed it by the bag in a cheap metal garden cart right next to the site but my new double wheel plastic wheelbarrow is easier on my ears when hoeing. A bag of quikrete doesn't go far and not as far as you may think. At my age, hoeing 6 bags is a good workout. Probably couldn't do it with my rotator cuffs the way they are.

Optimum water is whatever amount it takes to stir up a workable mix. The lowest water/cement ratio will make the strongest concrete. As others have said temperature is the problem now, want to keep it as cool as possible for a couple days to minimize shrinking and cracks.

If you can work it, it's got enough water.