Bit of Concreting advise

[Furniss]

As said already, 100mm of concrete with 142 mesh , laid on poly with exp board around perimeter.
Concrete is only as good as the ground underneath it. External We would control cut joints in a slab using a t bar at least 1/3 depth not more than an hour after laying as a couple of hours after laying the concrete has already decided where it's going to crack, generally cutting the joint the next day is too late.
Would always seal joints externally as rain water would seep through the crack and turn the ground underneath boggy resulting in cracked broken concrete especially if heavy trafficed.

So would you cut this slab as it is internal ?

 

[Volbar1]

So would you cut this slab as it is internal ?

I would exp joint around perimeter and pillars and cut joint between pillars to one side across to wall.

 

[Quattromike]

I'm not sure if you can get it there but possibly something like K-form could be an option for you, you set it up and it acts like a form to pour the conc in and use roller striker / screed rails on top of it, once set it acts like expansion joint. We used it on our yard and worked well for us.

 

[Brendan]

I'm not sure if you can get it there but possibly something like K-form could be an option for you, you set it up and it acts like a form to pour the conc in and use roller striker / screed rails on top of it, once set it acts like expansion joint. We used it on our yard and worked well for us.

Site was in a few years ago used that system, it was good. Only issue indoor would be you still need to free hand the edges or set another rail in down two sides

 

[Furniss]

I will free hand the lot - we usually do it this way and with small gravel and raking/conveyor into place till very close with laser then a alloy tamp usually gets its pretty good - its inside so no chance of a puddle.
Also water runs in all along back wall of building and across existing slab (building it is very deep compared to behind it and has a stream that runs along back wall at approx 3m higher than our internal floor level)so we are running a drain right along back wall and leaving it gravelled to surface to catch water before it goes on slab.
Client doesnt want channels.

 

[Furniss]

It looks like this slab might have to be poured in individual rooms, either end room then the center room to work our way out - which gives us things to consider for the joints.
Without wanting to over complicate it, I was considering drilling dowels through the wooden shuttering and tying it to the mesh and not treating it as an expansion joint - the whole area is is covered and damp and wont be subject to extreme temp swings from direct sunlight etc - or can we sleeve the dowel at the one side with DPM ?

Whats people thoughts ?

 

[DaveDCB]

personally I’d deffo mesh/dowel it straight through, I think your expansion will be minimal given the constant temperatures down there, contraction cuts in the door ways and it would be sound.. in my unprofessional opinion.
That kind of area I’d pump it it one go, won’t need dowel through shutting then.

 

[Furniss]

personally I’d deffo mesh/dowel it straight through, I think your expansion will be minimal given the constant temperatures down there, contraction cuts in the door ways and it would be sound.. in my unprofessional opinion.
That kind of area I’d pump it it one go, won’t need dowel through shutting then.

Cheers for the reply - its going to take a lot of gear to pour in one - and we dont have a lot of manpower - first bay has 100m2 and the existing slab is sloping and our pour over top will run from 10cm to 16cm thick to level it up.

 

[DaveDCB]

Not sure where your based, but we use a really good line pump gang , they put it at your feet, really only need one man on the rake, one laser, in between loads get on the beam screed

 

[Bitofdisbitofdat]

This is the detail for crack control joints on a floor I priced last year.

Very interesting that.

 

[Furniss]

Not sure where your based, but we use a really good line pump gang , they put it at your feet, really only need one man on the rake, one laser, in between loads get on the beam screed

Based in the sticks in France .... we are still very much stuck in the 80's with working practices, its always a battle to get what you want ....but its also what makes things great about it.

 

[T whiting]

If it's to.be done in sections I'd shutter it with k-form then you can dowel through them with sleeves on one side timber shuttering with dowels through it is always a nightmare to strip and usually involves smashing it out

 

[Furniss]

Its prepped up with wooden shuttering and dowels .... like you say we envisage a bit of a chew on to get it off - cant get hold of K-form.

 

[Shovelhands]

Its prepped up with wooden shuttering and dowels .... like you say we envisage a bit of a chew on to get it off - cant get hold of K-form.

try putting the sleeves on the dowels, with a bit of release oil inside the sleeve, then when the concrete is set, draw the dowel out, remove the timber and then insert the dowels. Just make sure the sleeve is against the shuttering or just into it, so you dont concrete the bars in. Have done this many times when its going to be awkward to remove shuttering.
K Form would have been handy, but nothing wrong with doing it with shuttering.

 

[Furniss]

Just to put the thread to bed

Finished the second pour today - the spec was a light tamp finish so we got a satisfactory result, the only bit I wasnt happy with was we had a long wait for the last wagon which left us a bit of an job to blend the two pours together,but I kind of expected it so made sure the join was in a dark out of the way area despite between told a couple of times there would be no delay
Lots of hidden work, we put a drain right round the outside walls as there is a stream runs above head height on the outside of back wall and this ran down internal walls and across old slab at a fair rate so our drain cut this off and we run this to an underground culvert (see photo)
Wooden form work came off the dowels o.k with some cuts with stone saw and we sleeved the second pour side.
Interesting job and a bit of a challenge for us as we dont do a lot of concrete work but I took it on because we do lots of work for the same estate and he wanted us to do it.
Anyhow thanks for the advice from everyone and it showed that there seems to be lots of different ways to do joint/form work etc etc
Photos attached - photos show first pour done b4 weekend and todays pour.
Cuts to be put in it soon as I can get on it.
EDIT: Added the culvert pic I forgot - this runs underground to a lake - its quite silted up but used to be able to walk through it to the lake;

 

[DaveDCB]

Nice tidy job that
We poured our kitchen/lounge floor on Tuesday, 14 cube in and washed up by 9am just me and the wife on laser duty and one pump guy

(Ross I’ve no idea what’s up with the photo upload on this forum? It’s the right way up while it loads then flips over when at 100% ?!)

 

[TiltyShaun]

Nice tidy job that
We poured our kitchen/lounge floor on Tuesday, 14 cube in and washed up by 9am just me and the wife on laser duty and one pump guy
View attachment 14996
(Ross I’ve no idea what’s up with the photo upload on this forum? It’s the right way up while it loads then flips over when at 100% ?!)

Glad you explained. I thought you concreted the ceiling!!

 

[V8Druid]

Just to put the thread to bed

Finished the second pour today - the spec was a light tamp finish so we got a satisfactory result, the only bit I wasnt happy with was we had a long wait for the last wagon which left us a bit of an job to blend the two pours together,but I kind of expected it so made sure the join was in a dark out of the way area despite between told a couple of times there would be no delay
Lots of hidden work, we put a drain right round the outside walls as there is a stream runs above head height on the outside of back wall and this ran down internal walls and across old slab at a fair rate so our drain cut this off and we run this to an underground culvert (see photo)
Wooden form work came off the dowels o.k with some cuts with stone saw and we sleeved the second pour side.
Interesting job and a bit of a challenge for us as we dont do a lot of concrete work but I took it on because we do lots of work for the same estate and he wanted us to do it.
Anyhow thanks for the advice from everyone and it showed that there seems to be lots of different ways to do joint/form work etc etc
Photos attached - photos show first pour done b4 weekend and todays pour.
Cuts to be put in it soon as I can get on it.
EDIT: Added the culvert pic I forgot - this runs underground to a lake - its quite silted up but used to be able to walk through it to the lake;View attachment 14997
View attachment 14987View attachment 14988View attachment 14989View attachment 14990View attachment 14991View attachment 14992

beautiful job Boyo ... and amazing place to be working .... that culvert is some drain