Concrete help
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Howard,
I can walk you through it if you like. Let me know if i can help.
I can walk you through it if you like. Let me know if i can help.
Raidiant heat? :drool Wife would be soooo happy.
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well the bigest part of the project will be the prep. you want to make sure your have a good base no organics and have it compacted good. Radiant heat under is nice but I hear it can cost an arm and a leg to run.
thickness would be on my mind for pouring concrete you want to make it thick enough for maybe a used oskosh or fwd
and you would want to go with a high strenth mix maybe 4-5Klb
oh and don't forget your rebar.
I'm sure Paul can shed alot more info on this
thickness would be on my mind for pouring concrete you want to make it thick enough for maybe a used oskosh or fwd
and you would want to go with a high strenth mix maybe 4-5Klboh and don't forget your rebar.
I'm sure Paul can shed alot more info on this
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My first ?s...
Yes I planned on 6" concrete.... do I need 6" of base below that (sand)
Yes I planned on rebar and hydronic tubing with a 2" reflective foam insulation. I don't plan on running it, but it is a lot cheaper now just to run the tubing.
For this type of environment, pour the slab in how many sections and then saw cut reliefs? or not do saw cuts and create more joints?
Yes I planned on 6" concrete.... do I need 6" of base below that (sand)
Yes I planned on rebar and hydronic tubing with a 2" reflective foam insulation. I don't plan on running it, but it is a lot cheaper now just to run the tubing.
For this type of environment, pour the slab in how many sections and then saw cut reliefs? or not do saw cuts and create more joints?
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Howard i'm not a concrete guy but I would do this probably over kill I'm sure but I would dig down 2' unless you have good base and put a crusher run compacting every 6" between lifts till you get it to where it has to be for the tubing and fowm insulation.I have never run anything under a driveway like that so I'm not sure on that part of it.As far as the control joints I would split it down the middle 15' and 15' by the 35 long also puting surface control joints or cuts after if that is easier segmenting it more. but the main joint they sell a backer that you can put bewteen to give it the expantion but also make sure the rebar conects the two. If you dont' do the split them a saw cut down the middle would be what most people would do. well right or wrong that is how i would do it if it was mine . but I think the base is the most important part of it. They did a driveway next to a job I was doing and they took it down very deep for the pavers so weather pavers or a pour the base would be the same and after a few years the diveway still looks great.
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Howard, like Cat said, whatever you decide to put in your driveway, the base is the key. Depending on your native soil conditions, a base of 3/4" crushed gravel under the slab is prefferd, for strength and drainage. The drainage is important to keep things in place and to prevent heaving. What type of soil/subsoil conditions do you have there? How deep does the frost get?
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Looks like somebody is going to get sweaty .....
What kind of finish , broom or stamped any color ?
What kind of finish , broom or stamped any color ?
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if you are sawing joints in, you should be ok with splitting it into 2 pours if doing it yourself ........caulking the joints (colored caulk) is something to think about also?? intregal coloring would be an easy way to make it unique, w/ a different colored caulk??...............BLACK, it'll melt snow faster:wink
base is important.......but thats not on a time frame??? I would definitely say pouring/finishing is what you need to be prepared for......grade is easily changed, but when the truck shows up, be ready ,cause once its on the ground you'll have x amount of time to make it right and thats it...........digging down 2ft for a driveway seems excessive, unless you have terrible soil conditions.......but if you have that much extra time and money then to each his own???
base is important.......but thats not on a time frame??? I would definitely say pouring/finishing is what you need to be prepared for......grade is easily changed, but when the truck shows up, be ready ,cause once its on the ground you'll have x amount of time to make it right and thats it...........digging down 2ft for a driveway seems excessive, unless you have terrible soil conditions.......but if you have that much extra time and money then to each his own???
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Broom...
I don't know about stain. Is it possible to find a DARK stain. Melts the ice better:grinz
As for sweating... not here... Highs in the summer are in the 60s with lows in the 30s at night. I think the record high EVER was 84 degrees...
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If you get behind on the mix you will be sweating your a$$ off at any temp
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+1. Finishing is always the biggest PITA for me. One thing you might want to consider is maybe having a SLIGHT pitch to it to aid in drainage. I don't know what the prices of crete are like in CO, but in CT they're pretty ridiculous. We poured a 6" concrete basement floor, roughly 60' x 40' and by the time it was done we were well over $15,000. But then again this was over the summer when gas was $5/gallon. We haven't poured concrete in a few months, so I don't know what the prices are like now.
Warning....rambling post alert!! :grinz
Concrete shrinks, that's why it cracks. The more water you add (to improve the workability) the worse the shrinkage will be, and the less strength it will have. Every 1" increase in the slump you get by adding water, will reduce the strength by roughly 10%. 1 gallon per yard will give a 1" increase in slump (rule of thumb) Not much, considering that the recipe calls for only about 30 gallons/yd to begin with. High strength concrete as used in the Interstate system has half that (very stiff) the workability comes with high-performance admixtures.
The batch plant has admix chemicals (plasticizers) they can add to make the concrete easier to work for a while, then it will flash off, and the mud will revert to it's normal state for it's 'age'. If the plant is close by, they can add it at the plant, if not they can send the measured amount out with the driver, and he can add it when you are ready. Have him roll the drum back to bring the mud to the drum opening, pour the admix onto the mud, have him mix it at full speed for 5 minutes. (or at least 70 rotations) He can use a minimal amount of water to wash the chemical off the fins if necessary, but no more than 2 gallons for a 8 yd mix.
Concrete shrinks in all 3 dimensions, for saw cuts, it's best to cut somewhere between 10' and 16'. the cuts need to be made withing 12 hours of the initial set of the concrete, provided nothing has really slowed down the curing process. The depth of cut should be 25% of the slab depth. This will give it a definite weak spot for the inevitable crack to start. you want to be in control of where the cracking is going to occur.
If pouring directly on you sub-base (no poly) be sure to wet it down so that it doesn't steel moisture from the concrete. If you're pouring on insulation as you state, then there shouldn't be an issue.
You can 'tool' in the control joints. but this is less certain to ensure the crack is in that spot.
Be sure to use sulphate resistant cement, and air entrainment, for the freeze-thaw resistance.
A lot of guys will tie the tubing on top of the rebar, because it is easier, but it also puts it closer to the saw cuts. If you know in advance where you are going to put the saw cuts, you could still put it on top of the bar, but make an allowance and sling it lower in the cut area, just be absolutely sure that is where you cut. I pumped concrete for a 20,000 sq ft shop and the plumbers put the tube on top, sure easier for them, but the contractor had to fix about 17 failures in the tube. He said afterward, that it should be underneath, but how to maintain the spacing? He said he'd lay down that cheapo welded wire reinforcing to lay out the pipe, then place the rebar, then tie the WWR up to the bottom of the rebar, VOILA!!
As far as color in concrete goes, it's expensive, but I've heard of guys using the cans of color powder for chalk lines. Throw a can in each truck, it's available in red, blue, brown, yellow, black.....just be sure to have the proportions right according to the size of the load. Not so bad for equal-size trucks, but if you have 6 and 9 yard loads coming, that's where it's tricky. The concrete guys may not like you doing it on site though, they must make certain their drum is absolutely clean if they are going to another slab next....it doesn't matter if they are doing piles, nobody will ever see the color of the concrete, but it will make a mess of a slab that isn't supposed to have color.
If you're uncertain of your concrete placing and finishing skills, do it in a couple different stages, a lot less stress, (time, tide and concrete wait for no man :wink) and you wont need a saw. Also, schedule the concrete for early morning, Slabs need attention, the guys pouring walls can do theirs in the afternoon, their mud doesn't need any attention after they've floated the top, they can go home....you'll still be baby-sitting yours.
Curing is a very important step....if the surface dries before it has cured, you will have a weak and chalky surface. Same goes for spraying water on to improve the finishing with a bullfloat. You destroy the water/cement ratio, and screw up the air entrainment in that thin layer, resulting in poor performing concrete.
99% of problems with a concrete slab are related to poor finishing. It's more or an art than a science. Batching concrete is just following a strict recipe, finishing is 'a pinch of this, a dash of that'....some guys can get away with that, others....can't.
Concrete shrinks, that's why it cracks. The more water you add (to improve the workability) the worse the shrinkage will be, and the less strength it will have. Every 1" increase in the slump you get by adding water, will reduce the strength by roughly 10%. 1 gallon per yard will give a 1" increase in slump (rule of thumb) Not much, considering that the recipe calls for only about 30 gallons/yd to begin with. High strength concrete as used in the Interstate system has half that (very stiff) the workability comes with high-performance admixtures.
The batch plant has admix chemicals (plasticizers) they can add to make the concrete easier to work for a while, then it will flash off, and the mud will revert to it's normal state for it's 'age'. If the plant is close by, they can add it at the plant, if not they can send the measured amount out with the driver, and he can add it when you are ready. Have him roll the drum back to bring the mud to the drum opening, pour the admix onto the mud, have him mix it at full speed for 5 minutes. (or at least 70 rotations) He can use a minimal amount of water to wash the chemical off the fins if necessary, but no more than 2 gallons for a 8 yd mix.
Concrete shrinks in all 3 dimensions, for saw cuts, it's best to cut somewhere between 10' and 16'. the cuts need to be made withing 12 hours of the initial set of the concrete, provided nothing has really slowed down the curing process. The depth of cut should be 25% of the slab depth. This will give it a definite weak spot for the inevitable crack to start. you want to be in control of where the cracking is going to occur.
If pouring directly on you sub-base (no poly) be sure to wet it down so that it doesn't steel moisture from the concrete. If you're pouring on insulation as you state, then there shouldn't be an issue.
You can 'tool' in the control joints. but this is less certain to ensure the crack is in that spot.
Be sure to use sulphate resistant cement, and air entrainment, for the freeze-thaw resistance.
A lot of guys will tie the tubing on top of the rebar, because it is easier, but it also puts it closer to the saw cuts. If you know in advance where you are going to put the saw cuts, you could still put it on top of the bar, but make an allowance and sling it lower in the cut area, just be absolutely sure that is where you cut. I pumped concrete for a 20,000 sq ft shop and the plumbers put the tube on top, sure easier for them, but the contractor had to fix about 17 failures in the tube. He said afterward, that it should be underneath, but how to maintain the spacing? He said he'd lay down that cheapo welded wire reinforcing to lay out the pipe, then place the rebar, then tie the WWR up to the bottom of the rebar, VOILA!!
As far as color in concrete goes, it's expensive, but I've heard of guys using the cans of color powder for chalk lines. Throw a can in each truck, it's available in red, blue, brown, yellow, black.....just be sure to have the proportions right according to the size of the load. Not so bad for equal-size trucks, but if you have 6 and 9 yard loads coming, that's where it's tricky. The concrete guys may not like you doing it on site though, they must make certain their drum is absolutely clean if they are going to another slab next....it doesn't matter if they are doing piles, nobody will ever see the color of the concrete, but it will make a mess of a slab that isn't supposed to have color.
If you're uncertain of your concrete placing and finishing skills, do it in a couple different stages, a lot less stress, (time, tide and concrete wait for no man :wink) and you wont need a saw. Also, schedule the concrete for early morning, Slabs need attention, the guys pouring walls can do theirs in the afternoon, their mud doesn't need any attention after they've floated the top, they can go home....you'll still be baby-sitting yours.
Curing is a very important step....if the surface dries before it has cured, you will have a weak and chalky surface. Same goes for spraying water on to improve the finishing with a bullfloat. You destroy the water/cement ratio, and screw up the air entrainment in that thin layer, resulting in poor performing concrete.
99% of problems with a concrete slab are related to poor finishing. It's more or an art than a science. Batching concrete is just following a strict recipe, finishing is 'a pinch of this, a dash of that'....some guys can get away with that, others....can't.
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Everything is more expensive in Connecticut.:wink
Concrete would be nice for the ability to do hydronic tubing... we will see. My intention is to get some work done around the house while the economy is slow. I was given a recent quote of $2200 to the driveway in asphalt. Last summer when oil went through the roof, I was told 5k IF they could get the materials. I already have roadbase down, and probably need to remove 6" of it to level out the driveway for asphalt. Our road wasn't paved till 3 years ago. I saw no point in asphalting/concreting the driveway till then.
We are doing a new garage/shop this summer.. Prices have dropped considerably with the lack construction going on. SIP panels have come down by 1/2. Concrete went from $160 a yard to $85 a yard...
Its cold and snowy here... I have a few more months of planning before I can do anything...
Concrete would be nice for the ability to do hydronic tubing... we will see. My intention is to get some work done around the house while the economy is slow. I was given a recent quote of $2200 to the driveway in asphalt. Last summer when oil went through the roof, I was told 5k IF they could get the materials. I already have roadbase down, and probably need to remove 6" of it to level out the driveway for asphalt. Our road wasn't paved till 3 years ago. I saw no point in asphalting/concreting the driveway till then.
We are doing a new garage/shop this summer.. Prices have dropped considerably with the lack construction going on. SIP panels have come down by 1/2. Concrete went from $160 a yard to $85 a yard...
Its cold and snowy here... I have a few more months of planning before I can do anything...
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.......Tell me more about this 40x60 basement that you had poured for $15k... at those rates, I may have to pack up the tools and take a little road trip for a season!!! Good Friday that's a lot of $$$... even if I had to do all the grading, buy a tri axle of stone, form doorways, install expansion, install poly, buy the crete (around $100/yd here depending on mix), rent a pump, pay a crew, etc. 40x60 @ 6" depth figured at 46 yds with generous waste figured.. $200 /yd with materials would be a high figure around here... so that puts me at $9,200.00 plus whatever I had in prep and equipment rentals. WOW tell me I'm missing something here... tell me it was 2 feet thick or something or I may have to consider this... opcorn2
opcorn2
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