Concrete driveway has large cracks

[Tagged]

Hi all.

Wasn't sure where to put this so thought this would be best. I have an old concrete driveway with large cracks in it and would like to go about filling them in as best I can just for aesthetics and general upkeep, although I know nothing will truly fix it. This driveway is like 50 years old.

BT have also gone across the driveway and repaired it again which has just broken up over the years. This was before I bought the house. It's made worse by me power washing it two or three times a year.

I was going to get some sand and cement and just smooth it over, should i be using concrete or a new thing seems to be grey silicone with cement dust?

Any help much appreciated thanks

 

[foxhole]

Pointless

 

[Tagged]

Pointless

Very helpful. Whys it pointless? I want to stop the holes getting bigger overtime

 

[Mr Chibs]

You could try 3 sand and 1 cement, mixed dry, then brushed over

It will fill, but will probably crack again

 

[Burnerman]

I have exactly the same scenario - unfortunately my drive is large so that means megabucks I can patch and patch, but the frost breaks the patches out every year.
I have had success with cutting the cracks vertically out with a stone cutting saw and then refilling but that can take a lifetime and still looks like a bodge.
The only real way is to break the concrete out and then go for a new surface....I'm considering block paving or maybe resin but either way will be very expensive so it will have to wait.
John

 

[foxhole]

Very helpful. Whys it pointless? I want to stop the holes getting bigger overtime

See Burnerman’s explanation.

 

[jj4091]

I have exactly the same scenario - unfortunately my drive is large so that means megabucks I can patch and patch, but the frost breaks the patches out every year.
I have had success with cutting the cracks vertically out with a stone cutting saw and then refilling but that can take a lifetime and still looks like a bodge.
The only real way is to break the concrete out and then go for a new surface....I'm considering block paving or maybe resin but either way will be very expensive so it will have to wait.
John

I thought they laid resin on old concrete, is that not so.

 

[Notch7]

I thought they laid resin on old concrete, is that not so.

Only if it’s a stable substrate, cracks indicate it’s not stable

 

[Burnerman]

Although my drive is quite well cracked, the cracks look to be historic, maybe due to a bit of land heave in the past....either way they aren't getting any bigger since I bought the property in 1986. It's just the edges of the cracks that suffer every winter.
I could get the concrete broken out and relaid but it's 6" thick and the area is pretty big (parking for maybe 7 vehicles) therefore the cost will be high. My incoming water main is down there too.
I don't know anything about resin drives as there is lots of sales hype rather than facts but it could be the way to go, especially if I made good the cracks first in the spring or summer time.
I'm wondering though, does resin need an upstand to keep it in at the edges?
Is it strong enough to use trolley jacks on?
Etc etc.
John

 

[bsr]

I don't think any contractor is going to resin over 50-year old cracked concrete.

Have you considered a tarmac overlay instead? Much cheaper too.

 

[Burnerman]

Good call, bsr.
For sure, I need the finished level to be as close to the original as possible so it blends with my patio and building dpc levels etc - Ive no idea how thick tarmac needs to be to make it strong and lasting.
I haven’t invesigated resins to any degree yet, I’m always sceptical about lifetime warranties etc.
John

 

[SFK]

Very helpful. Whys it pointless? I want to stop the holes getting bigger overtime

@Tagged
The strength of concrete comes from stones (evenly distributed from sand size to pebble size called ballast) being bonded together with cement (altogether making concrete) to form an interlocking mass with no gaps.

The larger stones overlay/interlock each other and provide a lot of the strength (it makes the concrete as strong as those stones). The smaller particles fill all the gaps. The cement fills the smallest gaps and chemically bonds it all together.

The issue with filling holes and gaps with new concrete is that there will be a boundary line where none of the stones interlock between the two.

So ANY thermal or stress movement that is different in the large mass from the small mass will cause the two to break apart at this boundary line.

Also one issue with newly laid concrete drives is that they can be over tamped or wetted on the top surface when laying. This beings more of the small particles and cement to the top forming a layer above the larger stones. This top surface is then weaker and often duster (for example unfortunately my garage floor).

SFK

 

[bsr]

I believe a standard overlay of 6mm tarmac is put down at a nominal 30mm thick

 

[Tagged]

@Tagged
The strength of concrete comes from stones (evenly distributed from sand size to pebble size called ballast) being bonded together with cement (altogether making concrete) to form an interlocking mass with no gaps.

The larger stones overlay/interlock each other and provide a lot of the strength (it makes the concrete as strong as those stones). The smaller particles fill all the gaps. The cement fills the smallest gaps and chemically bonds it all together.

The issue with filling holes and gaps with new concrete is that there will be a boundary line where none of the stones interlock between the two.

So ANY thermal or stress movement that is different in the large mass from the small mass will cause the two to break apart at this boundary line.

Also one issue with newly laid concrete drives is that they can be over tamped or wetted on the top surface when laying. This beings more of the small particles and cement to the top forming a layer above the larger stones. This top surface is then weaker and often duster (for example unfortunately my garage floor).

SFK

Excellent explanation thanks for that much appreciated.

I guess I'll just leave it alone I suppose!