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Posted: Tue Feb 12, 2013 7:48 am
by GB_Groundworks
Pouring 540m square floor 110m3) in a factory next few weeks and its in 5 metre bays, going to use the new kform screed rails, i was thinking about roller striking or twin beam screeding it.
we've done some big pours but they always been on irregular shape pads or bays etc 50m3-100m3 pours so we've used the smaller magic floats (strimer engine on aluminium L section) and string lines and laser levels to get them level
its a 200mm slab concrete spec is C35 M330 20LS C2 cement (28% PFA Blend) S3 Pump
as i see it the twin beam can be operated by one guy pulling, one raking and has the weight to stay down on the rails
roller stiker need two to pull one to rake, and then the power pack etc and lines where as the beam is self contained albeit heavy, used a 3m one in the past.
any thoughts please gentlemen, no suggestions of 6x2 with some handles railed on though please 
hehe
Posted: Tue Feb 12, 2013 9:36 am
by Tony McC
Roller striker is great for when you need a lot of fat at the surface, so PIC or exposed agg jobs, but for industrial floors or power floating, give me the twin beam screed any day.
Posted: Tue Feb 12, 2013 11:57 am
by msh paving
Roller everyday,
Twinbeams are old had rattly shaky things,
I work with a friend alot, myself I have a 6m roller he has them upto 10m ,perfeclty flat surface ready to power trowel,a 5m bay can be done with a vibrstrike, speedcrete ltd hire them and rollerstrikers,
If you used a twinbean at 5.5m wide one man would struggle to pull it, MSH 
Posted: Tue Feb 12, 2013 12:01 pm
by TheRockConcreting
I've been meaning to wright a post about all the different ways of screeding/striking a concrete slab. Used them all and the vast majority are crap!
The best tool by a county mile is a screed, one man can easily handle 300m2 with two on the rakes, large scale pours of around 1000m2 it takes four screeders. This screed will have the floor super flat, or as good as your laser is!
Next best is a screed beam, realistically this is more suited to the large scale pours than the above screed, two men with three rakers can easily pour 1000m2 in six hours. Not as super flat as above but the differnce is not worth talking about.
Roller screeds IMO are trying to solve a problem that does not need fixing, and in doing so caused more hassle. Why? They work fine on the first bay but with no extra gain over the above screeds, the problems start when you come to do the next bay. The little bits of agg and cement paste that before where just falling off the other side of the screed rail now build up on the other slab!
Vibrating dual screed beam Looks like a one man screed! Nope! This screed should never have been invented! The only time i've ever found a need to use the hand bar in the middle is when the screed over lapped half of a slab we had already screeded, otherwise its a two man job pulling from either end, its really not easy and i would stay clear of it.
With the Magic screed, there's nothing magic about it. The thing works on an average basis. People seem easily fooled by this tool because it leaves a nice vibrated surface, and to the untrained eye looks nice. Look closely and you can see shiny low spots and darker patches which are the high spots! If its a job where level tolerance is not a be issue say like a chicken shed then this 'magic' screed will be of use.
Whats left? oh yeah the Tampers! I see this all the time, piss wet mud being slapped with a bit of 2x4 like some euro bondage porn flick. Wrong for so many reasons. The only time a proper tamp should be used is on dry 50/60 slump concrete to move the large agg down from the surface.
Posted: Tue Feb 12, 2013 12:13 pm
by msh paving
Why in this day and age would you what to use a free hand screed to finish the concrete, rails set up pull roller straight down the bay,hit and miss bays no problems always flat,
we have done 300cube pours with a laser and vibrostrike no problem at all,again makeing less hard work MSH
Posted: Tue Feb 12, 2013 12:21 pm
by TheRockConcreting
Every master concreter i have every known uses hand screeds and always will. A great test to see if the floor is really flat or just seems it is at 6am sun rise.
Posted: Tue Feb 12, 2013 7:06 pm
by lutonlagerlout
we used a 5 m dual screed beam before xmas on a slab and it was me pulling and 2 men, 1 on the rake and 1 on the shovel
the shutterer (a man of 47 years experience of concrete) said they use them all the time on big jobs,the only difference being is that they use road forms for shutters
i would like to see anyone on this forum who can tee up 1000 m2 of concrete to be poured in 6 hours, 15 wagons in and out?
most we have managed in a day was 7 due to many factors
incidentally the shutterer mick is working at centre parcs in woburn which has used a humungous amount of concrete
the whole job has to be finished in 72 weeks
LLL
Posted: Tue Feb 12, 2013 7:22 pm
by Carberry
How much would you be looking at for 1000m2 of concrete?
Curious on costs, thinking of moving to a bigger yard, would need palisade fencing and ideally it would be concreted. I would probably have to buy a bit of development land and do it all myself though.
Posted: Tue Feb 12, 2013 8:22 pm
by msh paving
Carberry wrote:How much would you be looking at for 1000m2 of concrete?
Curious on costs, thinking of moving to a bigger yard, would need palisade fencing and ideally it would be concreted. I would probably have to buy a bit of development land and do it all myself though.
Supply and fix 1000m2 150mm thick 1 layer a252 mesh you would be looking at £40-47m2 thats on the light side
I have not seen a twin beam tamper in this area for years,everyone doing slabs use roller strike or a vibro strike and laser,a friend i do work with has just done 4 acres of concrete 2 layers steel road forms and roller average 550m3 a day pumped one wagon every 7 minutes running from 2 plants 6m roller -2 men 3men on rakes one man on pump, 1 drop onto powerfloat when needed but they are kitted up concrete men
Posted: Tue Feb 12, 2013 9:12 pm
by GB_Groundworks
Just got back from stripping concrete out, I had a roller striker on order and it has it advantages about retaining aggregate in the top of the slab, but requires more men and is more awkward.
We've got 5 jobs on at mo so spread thin ill have 3 lads inc me as everyone has to be inducted hse 2 hour induction
Depending on pump price we'll do two or three pours
Ill get a price on the double beam screed cheaper than the roller striker
Posted: Tue Feb 12, 2013 9:15 pm
by GB_Groundworks
Carberry wrote:How much would you be looking at for 1000m2 of concrete?
Curious on costs, thinking of moving to a bigger yard, would need palisade fencing and ideally it would be concreted. I would probably have to buy a bit of development land and do it all myself though.
I'm in at £60/m2 for this with removing existing etc
Throwing more work at us every day
Posted: Tue Feb 12, 2013 10:01 pm
by GB_Groundworks
I'm sorry rock but I've not seen a manual screed on a big pour in 20 years it's all laser screeders, the big self propelled ones or the little trolley mounted ones, or huge beam screeds.
To many hs problems with all that bending and repition not to mention concrete contact plus 300 in a day is no good when I need to do it and get it floated as well
Posted: Tue Feb 12, 2013 10:15 pm
by msh paving
GB_Groundworks wrote:I'm sorry rock but I've not seen a manual screed on a big pour in 20 years it's all laser screeders, the big self propelled ones or the little trolley mounted ones, or huge beam screeds.
To many hs problems with all that bending and repition not to mention concrete contact plus 300 in a day is no good when I need to do it and get it floated as well
i'm with you on that giles, beams went out years ago,
MSH
Posted: Tue Feb 12, 2013 10:35 pm
by GB_Groundworks
All the big pours are still beams watched a program about pouring the new Golden Gate Bridge they had a 100 metre beam that levelled consolidated and grooved it
Posted: Wed Feb 13, 2013 5:50 am
by seanandruby
whatever you use it is still important to have enouugh men in the gang, 3 of you seeems a bit light to me.