There wuz I Digging this 'ole .....

[ToughButterCup]

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[PeterW]

You may find pre-mix postmix is just as quick and cheap. Slit the bag and dump the dry content in, spray with the hose from time to time and job done as it sets really quick. 

[Nickfromwales]

13 minutes ago, PeterW said:

You may find pre-mix postmix is just as quick and cheap. Slit the bag and dump the dry content in, spray with the hose from time to time and job done as it sets really quick. 

?????

[Jeremy Harris]

20 minutes ago, PeterW said:

You may find pre-mix postmix is just as quick and cheap. Slit the bag and dump the dry content in, spray with the hose from time to time and job done as it sets really quick. 

 

 

Just watch the temperature rise!  Postcrete gets bloody hot as it cures, especially in large quantities.  I found this out when casting up concrete bollards in a plastic bucket.  I'd been mixing concrete to make them, but had a bag of postcrete left over from the fencing. so made one bollard from that. Not only did it get hot enough to distort the bucket, so I had to cut it off, but it also ended up with cracks right through it.

 

Not sure how postcrete and a fibreglass tank would get on together - it might be that the water in the tank plus the natural ability of the soil to absorb heat would keep it cool enough, but there was steam coming off the bucketful I mixed up, so I'm not sure I'd trust it not to cause heat damage to the fibreglass.

[Russell griffiths]

Why not hire a dumper. £75 a day around here. 

Can you get your old Landy near it with a trailer on the back. 

[ToughButterCup]

32 minutes ago, JSHarris said:

Our guys backfilled around ours with a dry mix, poured down a plastic waste chute fitted in a channel cut into the side of the hole to get it to the bottom.  They kept the tank half full of water suspended from strops on the digger whilst they did this.  The hole was around 1/4 to 1/3rd full of water at the time.  It was a bit like using postcrete, pouring a dry mix into a hole with water in it. 

 

They poured concrete up to around 150mm or so above the triangular anchor lugs that stick out near the bottom of the cone, let the concrete go off a bit, then filled the rest of the hole up with pea shingle, which added to the  ballast holding the tank down as it was resting on the ring of concrete at the bottom.  As soon as the pea shingle was in, they untied the tank from the digger and pumped more water into the tank to hold it down. 

 

So, water already the  'ole doesn't matter : our water level is - at most - 6 inches above the bottom of the cone resting on the bottom. Technical this hole-filling lark innit?

 

As can be seen from the image of Debbie's feet (above) the diameter of the hole is roughly a meter, and I'll bet that where her feet are is where the lugs are that we have to cover  - say another meter and a bit (.5).

 

So that's Pi r squared h innit? 

3.14 * 0.5 *0.5 *1.5  say 1.2 cubic meters of concrete.

Its a bugger because, at 2.5 meters deep, with a 2.6 tonne digger, you can't dig a conical hole. But, at the time, needs musted.

 

So I need half a tonne of cement and about 3 tonnes of ballast

20 bags of cement (25 kg) (£4.15 each)  £83 and 

3 bags of ballast   say £40 each  £120

Shingle : say £100's worth

That makes £300 : damn, that old codger @Russell griffiths was right. Hmmm.

 

@Russell griffiths, if I can get the Landy near it, I will. The 'outfield' needs a bit of landscaping first though

[Triassic]

If I’d have known you were mixing concrete I’d have stayed and given you a hand. Mind you there was no one on site when I arrived!

[Triassic]

 

 

Why not get Baymix to deliver a dry mix and barrow that across and shoot it straight into the hole

Edited September 1, 2018 by Triassic

[ToughButterCup]

1 minute ago, Triassic said:

Why not get Baymix to deliver a dry mix and barrow that across and shoot it straight into the hole

 

Tell ya wot, come and show me how: free coffee and cake while you barrow 3 tonnes of concrete15 meters a time........

 

I will be setting the mixer up next to the hole after having divided the one tonne bags of materials up into lots liftable by the digger (half a bag or so) ; then use J's idea of making a chute down the side of the tank (cutting the bases off a pair of old plastic dustbins) and tipping it in. Top off with some of our pile of pea gravel.

Then fuss the original spoil into a nice level area round the inspection hatch ready for the new lawn - having made provision for the incoming foul drain runs and the electricity supply.

[Onoff]

As @newhome says. MTFU!

[newhome]

1 minute ago, Onoff said:

As @newhome says. MTFU!

 

Only to you sweetie . You started that tiling yet? 

[Russell griffiths]

Your digger should pick a whole bag up

put the digger with the blade facing the way you are going to go

put a pallet on the ground with one end cocked up on top of the blade

skull drag the bag on a short strop towards the pallet

drag bag half up pallet 

use wide ditching bucket to hook under far side of pallet and lift as you raise blade

track to destination 

i can move a 3/4 bag with my 1-1/2 tonne machine so you should easily move a whole bag. 

 

But then again us old codgers do know a few tricks. 

[ToughButterCup]

1 minute ago, Russell griffiths said:

[...]

use wide ditching bucket to hook under far side of pallet and lift as you raise blade

track to destination 

[...]

 

I've done that with flag stones and a couple of telegraph poles. But didn't think to extend the idea by putting the heavy weight on a pallet.

Thanks Dad.

Ian

 

[Onoff]

25 minutes ago, newhome said:

 

Only to you sweetie . You started that tiling yet? 

 

Nah, possible problem with my ring at the mo. Looking into it now.

[Tyke2]

On 24/08/2018 at 17:37, Triassic said:

You don't necessarily need to concrete the tank into the hole, you can fill the tank with water as you backfill around it with selected backfill. The weight of the water in the tank keeps it down!

This is good advice. Also if you are concreting the tank in, fill the tank with water at the same time/depth as the concrete pour, as the tank could float up out of the concrete. I remember we had to do this once, albeit on a 32000 litre SUDS tank.

[joe90]

When mine was installed (very high winter water table) the concrete was dumped by the gate, I loaded it with my JCB into a dumper which took the mix to the tank and digger driver scooped concrete into the void around the tank, it was a dry mix and only took about an hour.