Baffles for a slab
#1
06-23-03, 12:15 PM
Baffles for a slab
I (along with some help) am pouring a 16' x 4' slab... I know it's alot to do, but "hey, why not!" I can use some practice.
To make things a little easier I would like to pour the slab in 4 different 4' x 4' sections, but still have 1 solid 16' x 4' slab.
Is that possible??? Someone suggested using baffles? How do I use baffles to seperate the sections, but still have 1 solid slab?
To make things a little easier I would like to pour the slab in 4 different 4' x 4' sections, but still have 1 solid 16' x 4' slab.
Is that possible??? Someone suggested using baffles? How do I use baffles to seperate the sections, but still have 1 solid slab?
#2
06-23-03, 02:26 PM
They are called "keyways"......you can buy the metal kind that stay in the slab at places that sell rebar, etc for concrete work....or you can make your own out of wood....
Picture a 1x4 standing verticle.....about midway in the board, you have a 1x1 nailed on the side you are going to pour the first slab......you also drill holes in it to run rebar thru......about 1' apart for your slab.....centering the rebar in the center of the 1x4 vertically. When you pour the first slab, and take the form away in a day or two, there will be a 1x1 groove in the slab with rebar sitcking out a couple feet.....
Picture tongue and groove flooring.......
The next pour, you move the keyway form to the far end, pour, and the concrete will flow into the groove in the last pour, and the rebar will tie the new pour to the first......and so on down the line....
They "really" aren't "ONE" slab......and can't be if you don't pour them as one, but this is the way control joints are done in bigger slabs and they will tie together via the rebar.
Picture a 1x4 standing verticle.....about midway in the board, you have a 1x1 nailed on the side you are going to pour the first slab......you also drill holes in it to run rebar thru......about 1' apart for your slab.....centering the rebar in the center of the 1x4 vertically. When you pour the first slab, and take the form away in a day or two, there will be a 1x1 groove in the slab with rebar sitcking out a couple feet.....
Picture tongue and groove flooring.......
The next pour, you move the keyway form to the far end, pour, and the concrete will flow into the groove in the last pour, and the rebar will tie the new pour to the first......and so on down the line....
They "really" aren't "ONE" slab......and can't be if you don't pour them as one, but this is the way control joints are done in bigger slabs and they will tie together via the rebar.
#3
06-23-03, 05:00 PM
Thanks for the help...
Is there a way to do the whole slab in one day? The main reason I am considering doing it in sections is that if I run into a problem, realize I'm doing something wrong, etc., I can do things differently in the next section.
I of course also have a concern that since I am mixing and pouring the 16' x 4' slab (with help), the early parts will begin to setup before I finish the last part. How much 'play time' will I have with the concrete???
I will use 50+ bags, and an electric mixer that holds 3 per load... that's 16+ loads. Very time consuming and lots of labor, but I have 32 bags that were given to me... might as well use them!!!
Is there a way to do the whole slab in one day? The main reason I am considering doing it in sections is that if I run into a problem, realize I'm doing something wrong, etc., I can do things differently in the next section.
I of course also have a concern that since I am mixing and pouring the 16' x 4' slab (with help), the early parts will begin to setup before I finish the last part. How much 'play time' will I have with the concrete???
I will use 50+ bags, and an electric mixer that holds 3 per load... that's 16+ loads. Very time consuming and lots of labor, but I have 32 bags that were given to me... might as well use them!!!
#4
06-23-03, 08:45 PM
Pour it at one time. Unless you plan on placing rebar at 18" maximum centers with the minium embedment length across each joint, the slab will never act as a single unit, and the joints will eventually open and leak, grow weeds, and settle unevenly.
Order a batch from the local plant and place it in one morning.
Order a batch from the local plant and place it in one morning.
#5
06-23-03, 09:44 PM
Thanks to both of you!
I am pretty committed to pouring it myself (with 3-4 people helping). I can borrow a mixer for free, and I already have 32 bags of Quickrete that were given to me by a neighbor, and they are just taking up space in my garage... I figure I only need 20+ more.
Basically, if I pour the whole thing at once... How long do I have??? How quickly can I expect to work with the first cement that is poured?
I am pretty committed to pouring it myself (with 3-4 people helping). I can borrow a mixer for free, and I already have 32 bags of Quickrete that were given to me by a neighbor, and they are just taking up space in my garage... I figure I only need 20+ more.
Basically, if I pour the whole thing at once... How long do I have??? How quickly can I expect to work with the first cement that is poured?
#6
06-24-03, 03:40 AM
Assuming you pour it 4" deep, that's only 22 cubic ft....you should be able to do that easily in time to finish it as well......You should have couple hours before the first end is ready.
A tip......buy enough portland cement to throw in with your Quikcrete at ratio of one bag portland to every 5-6 bags of Quikcrap......they REALLY scimp on the amount of cement in that stuff....it's more sand and gravel than anything else....ok for setting a post, but you'll never get a decent finish on a slab with that stuff....
A tip......buy enough portland cement to throw in with your Quikcrete at ratio of one bag portland to every 5-6 bags of Quikcrap......they REALLY scimp on the amount of cement in that stuff....it's more sand and gravel than anything else....ok for setting a post, but you'll never get a decent finish on a slab with that stuff....
