What do you put in it?

[Quattromike]

I'm half planning on pouring a strip of concrete retaining wall/block during the hols, weather and energy dependent.
It'll be around 300x600 and 40M long when done. I'm bolting a steel post fence on top afterwards. I've got shutters of a sort and they will allow me to do it in 6M segments.

What do you use in between the segments as an expansion joint?
I've seen the builder using MDF board.

What do you add to the concrete mix to help the finish other than more cement?

How many hours do you leave shutters on for before you remove and reset.

 

[Gunners]

What do you use in between the segments as an expansion joint?
I've seen the builder using MDF board.

What do you add to the concrete mix to help the finish other than more cement?

How many hours do you leave shutters on for before you remove and reset.

A good poker is your friend for getting fair face concrete. Its air pockets that are your enemy rather than the mix design per say.
I wouldn't strike it any less than 24hrs after pour but the longer you leave it the less potential to damaging the face you will find. Use a good mould release agent on the face of the shutters. @Giles is the man for concrete on here really, check with him.
As for expansion/ day joints, they want to tie the sections in together really and there are several ways to do this. Again Giles probably knows some systems but I'd say you want to make it waterproof or as its a retaining wall, you will find the water using the joints to weep through especially in wet ground. To be honest, this isn't the best time of year for that kind of work. Plants close down and do a lot of maintenance this time of year, drivers cant be arsed to work, weathers crap and at 40m long, that's a lot of 6m sections to be erecting, pouring, waiting and striking over the week we actually have available!

 

[6feetdown]

I would think fibre board as the expansion with a couple of tie bars through 1 side on sleeves so it can expand and contract. Polysulphate type of mastic in the finished joint. Clean stone and land drain behind with a waterproof board on the back of the wall. But not an expert on this but sure it would work

 

[groundworker]

Expansionthene | Lemon Groundwork Solutions Shop

Expansionthene is a closed cell expanded polyethylene foam fillerboard that is tough and versatile which provides a rot proof, non absorbent, and non extruding fillerboard.

www.lemon-gs.co.uk

Use this stuff for expansion material, has a strip that rips off to leave void for sealant.

You might want to ask for 10mm aggregate to flow better if you are using a lot of reinforcement.

You can use an expanding waterstop in the joints to stop weeping but that's different from an expansion joint.

 

[Quattromike]

To be honest, this isn't the best time of year for that kind of work. Plants close down and do a lot of maintenance this time of year, drivers cant be arsed to work, weathers crap and at 40m long, that's a lot of 6m sections to be erecting, pouring, waiting and striking over the week we actually have available!

TBH it's been a plan thought up last year but has never moved much because of lack of time off from day job so have got myself organised with some shutters and a pallet of cement and will put on the robustrac mixing bucket and do bits and pieces where I have a few days during the holidays. Don't think I'll get many sections done but would like to make a start at least.
I wasn't really planning on putting expansion joints in but it's been mentioned it could crack at 40m without something to let it move a bit but TBH one side will be almost buried and the other side is not overly exposed. The most force on it will be the 8' close board fence I'm planning on the top afterwards

 

[Giles]

smooth shutters, good coat of soap oil or shutter release is always handy for getting smooth faces, good concrete and good vibe with poker also essential

how are you fixing/ bracing your shutters? any through bolts etc?

if its just a wall for a fence a day joint will be fine with a sliding dowel joint with a sleeve

 

[V8Druid]

smooth shutters, good coat of soap oil or shutter release is always handy for getting smooth faces, good concrete and good vibe with poker also essential

how are you fixing/ bracing your shutters? any through bolts etc?

if its just a wall for a fence a day joint will be fine with a sliding dowel joint with a sleeve

wha's one of them Giles

 

[DaveDCB]

Grab a brew and have a good read, Tony was a wealth of knowledge

Concrete Movement Joints

A guide to the various types of joints used in concrete slab work

www.pavingexpert.com

 

[TiltyShaun]

Vegetable Oil is a good get you out of trouble for Mould release oil. Available in most corner shops or petrol station shopping sections!!

 

[Brendan]

Any reason it can't be blockwork?

 

[Quattromike]

Any reason it can't be blockwork?

I can't lay block.

 

[Quattromike]

smooth shutters, good coat of soap oil or shutter release is always handy for getting smooth faces, good concrete and good vibe with poker also essential

how are you fixing/ bracing your shutters? any through bolts etc?

if its just a wall for a fence a day joint will be fine with a sliding dowel joint with a sleeve

It'll have thought tie every 4' . I've got a mega vib poker to push it it. The shutters are steel but not sure if they will float with pokering or if I need to pin down into the ground somehow. Might see if I can get fiber board for between the joints

 

[Giles]

It'll have thought tie every 4' . I've got a mega vib poker to push it it. The shutters are steel but not sure if they will float with pokering or if I need to pin down into the ground somehow. Might see if I can get fiber board for between the joints

Definitely needs fastening down

 

[V8Druid]

I can't lay block.

neither could I when I started but after 1200, 9" hollows on me retaining wall, I'd got the hang of it

 

[Quattromike]

Definitely needs fastening down

The ground is not totally flat so was thinking about pouring a couple pads along the length to help level out a bit and gives something to fix to to hold it in position. But ye old spike knocked in here and there probably be the go to fix

 

[Giles]

Can’t you get some flat top concrete Lego blocks to build off?

 

[Quattromike]

That was considered, but because the fence is 2.4 high and posts are 3m centers I wasn't confident the block the post gets fixed to will stay put in the wind whereas if it was big long joined block it's more likely to hold steady

 

[6feetdown]

That was considered, but because the fence is 2.4 high and posts are 3m centers I wasn't confident the block the post gets fixed to will stay put in the wind whereas if it was big long joined block it's more likely to hold steady

Steel fence rails?

 

[V8Druid]

That was considered, but because the fence is 2.4 high and posts are 3m centers I wasn't confident the block the post gets fixed to will stay put in the wind whereas if it was big long joined block it's more likely to hold steady

spike top palisade ??

 

[V8Druid]

That was considered, but because the fence is 2.4 high and posts are 3m centers I wasn't confident the block the post gets fixed to will stay put in the wind whereas if it was big long joined block it's more likely to hold steady

make up some fish plates and drill fix the tops of the blocks together ?