Concrete help please

[bigralphie]

Couple of years ago I patched some potholes in my back yard with leverbuild pothole repair cement ,I thought I had done a good job followed the destructions to the letter etc
Anyhow it has all cracked again and I am back where I started can anyone recommend a better method or product please ?

[GringoRojo]

how deep was the original hole? if not very, that could be the problem.

[paul1606]

My wifes gravy

[bigralphie]

Nice one Paul lol.holes are about 2" deep Alan

[rjd1]

any concrete less than 6 inches will crack and break
dig it out a bit drill 10mm holes into existing concrete get couple metre`s 10mm metal dowel bar cut bar into small 4-6 inch lenghts place half into drilled hole leaving other half exposed in the hole
simply fill with concrete level leave for couple of hr`s re-trowel it make it smooth or brush finish
once start`s to cure try and avoid any traffic from using for a couple of day`s
 

[pitternator]

rubbish !..if so , how come 40mm paving slabs dont break all on their own !  lol
 
its all about mix strength, foundation prep and use of the material. Ralphie, you need to ask why the hole appeared in the first place...and that will determine how you repair it. If its a car / van wheel loading  doing the damage, possibly no repair will last ... and what is the condition of the drive itself  ...possibly it is unsuitable for the task in the first place etc...
 
concrete will crack at 40 times its thickness all by itself, so is this a factor ?Is the hole at the limit point of a large slab...as it could be the reason why it starts to crumble.
 
If a ground slab is well laid over a well prepared foundation, 100mm should be adequate for a 4m length without cracking  .....but without knowing the base structure, loading and other conditions, its hard to say just what will last .

[rjd1]

ok slabs are made in a press mould as are block`s etc
was just offering advice  22yr in building game assumed sub base would of been pre checked
 

[BBROWN1664]

that home made concrete mix is weaker than what readymox deliver anyway so would need to be much thicker to achieve the same results.

My guess on the issue BR is the hole was a bit too shallow and possibly not clean enough. Also, was there a rough surface to allow the new concrete to bond to the old concrete?

[bigralphie]

It’s a Victoria terrace rear yard ,The concrete is laid over soil with aggregate mixed in would think it was done at least 50 or so years ago( I have own the house 20 years) .
I think reading the replies the holes are too shallow and I guess wheeling bike in and our has done the damage over the years.
last time I got some gravel and lined the bottom of the hole ,did the mix with a spot of fairy liq in and mix it so it was quite stiff (and threw the remaining gravel in)
The last couple of hard winters have not helped and as I wash down and brush the yard every couple of days because of the dog that has finally done for it

Is all repair stuff about the same quality ?

[ridgemere]

Trying to maintain a 50 year old cracked concrete slab is the same as flogging a dead horse, very frustrating.
The biggest enemy of concrete is water and freezing weather. Water gets into the cracks, freezes, expands, and your left with a hole full small rubble.


Cure. Rip it all out.
Get rid of all top soil, put in a sub-base of 150mm of compacted mill waste, lay a minimum 100mm (150mm ideal) with some reinforcing. Put a small gradient in the concrete towards a drain to stop the puddles. If it is a large area your concreting, put in a movement joint because over the years the sub-base WILL move.


If can't be arsed to do all that get someone else to do it. Failing that carry on repairing like rjd1 suggests but be aware larger repairs last better than smaller ones (that's why the council dig up half the road for a small hole) and never use fairy liquid.

[bigralphie]

I was afraid you was going to say that lol. best get saving

[pitternator]

hmmm...readymix cement ratio varies according to the job its doing. I reckon many householders will over do the cement rather than under ...tbh, IMO its the whole drive which is the issue.
 
I only have 40 yrs building experience, including several years in  civil engineering building reinforced concrete foundations and structures...so wtf do I know !   

[ChrisJH]

My dads drive is old and has a couple of pot holes, as an alternative to taking it out and doing again (the correct way) I put a couple of 5mm steel plates approx 900mm - 900mm over the holes, it spreads the loads keeps the tyres out and will do for a few years.

[ridgemere]

Large steel plates do a good job of spreading the load Chris and I'm sure they look very nice on your dads drive way.
But I wouldn't like to walk and push my bike on them on a wet or frosty morning.

[chris.biker]

May be cutting the concrete where the damage is and setting in a concrete slab, one of the 3'' thick ones'' then would be easy to replace in the future if it wears or is cracked.

[Sunny Intervals]

Dead concrete is dead concrete
I'd get it overlaid somewhere between 20 to 40 mm Tarmac, It will work out cheaper that trying to patch and repair it.
Or trying to lay new concrete drive when you consider costs of spoil removal and labour required to lay new sub base and such.

and if you ground is moving under the slab, when the slab been cracked and overlaid it's flexible and will accommodate the movement

[locksmith]

Q. How many foccers does it take to change a light bulb?
 
A. About twenty, 1 To ask the question and the other nineteen telling him completely different ways to do it.