I've got an issue with my exposed aggregate driveway. I have a 2 year old son who is running around like a madman and takes heaps of stacks,the driveway acts likes his own personal skin grater . Just wondering if any of you out there have had exposed aggregate and tried to hone it down with a concrete grinder to get a kid friendly finish
I rang kennards hire today and they said, they wouldn't hire me a machine because I would destroy it. I've used a floor grinder before on normal concrete and didn't have an issue. Is exposed the same
The effort to grind concrete or exposed aggregate is the same. The kennards guy was full of crap in his pants not to let you rent it.
OPTION
Depending on the size and level of finish you want to achieve, and how big the area you want to finish, this machine should do the trickhttps://www.toolmart.com.au/pc5000c.html?gclid=CI74-bPOh9ACFYWXvAodVgIAAw
Just get the right diamond grit to start with (course first then a second or third polish) shall give a reasonable result. This has to be done wet so a great job to do in the summer.
I'm thinking more the stand up job, even twin head. I've got 264square meters but was only going to do behind the gate for now so around 180.
What level of exposed aggregate are we talking about here? Is the bluestone really exposed, or just poking through a little?
If the bluestone is just exposed then a floor grinder will do it for you. If there's a lot of it exposed then forget about the floor grinder. Look at re-sealing it.
Those stand up floor grinders sit on their grinding stones as they spin, and dont spin at high revs, so there's plenty oppurtunity for things to catch. Not to mention you'll be there for quite a while trying to flatten it since the bluestone is a lot harder than the mortar material around it. They're great if you want to remove a millimetre or two of the top of a flat piece of concrete, not really great if you want to flatten a really rough surface
A concert grinder/ polisher will flick out plenty of agg on an exposed job, however you can get it down re grout then a quick honed finish, which is exposure but trafficable and smooth
I'd then apply a poly sealer, which makes it stain resistant, got photos if you want
Select to expand quoteSubsonic said...
What level of exposed aggregate are we talking about here? Is the bluestone really exposed, or just poking through a little?
If the bluestone is just exposed then a floor grinder will do it for you. If there's a lot of it exposed then forget about the floor grinder. Look at re-sealing it.
Those stand up floor grinders sit on their grinding stones as they spin, and dont spin at high revs, so there's plenty oppurtunity for things to catch. Not to mention you'll be there for quite a while trying to flatten it since the bluestone is a lot harder than the mortar material around it. They're great if you want to remove a millimetre or two of the top of a flat piece of concrete, not really great if you want to flatten a really rough surface
Depends on machine, a pro machine carries a heap of weight and takes 2/3 mm in a pass, cheap sit lightweight machines will struggle
Are you planning on having more kids?
If not, chances are by the time you get the job all completed, your son will have learned his lesson about not face planting on the driveway, kids learn pretty quickly.
Also, what's next? There are threats everywhere.
I speak from a place of experience, I found myself going down that slippery slope when my daughter first got to her feet, but soon learned that I couldn't remodel the world. She survived those years just fine.
The rocks protrude about 5mm out of the concrete . Bluestone and quartz.
I know you can't eliminate all risks but when you have got a massive driveway that the grom can't even skateboard on it's pretty ****e. And doctor you sometimes really are a tool .
Thanks for the advice guys I might speak to the local grano and get their opinion to
Back on topic.
It sounds as if there is an issue with the concrete formulation, possibly some anti weathering agent was not used (if such a thing exists)
Smoothing of the aggregate will most likely only be a temporary fix until the cement erodes again (however long it took from the driveway first being laid).
Best option for a permanent long term fix is to have it coated, although this would most likely be fairly expensive based on your meterage.
Select to expand quoteelmo said...
Back on topic.
It sounds as if there is an issue with the concrete formulation, possibly some anti weathering agent was not used (if such a thing exists)
Smoothing of the aggregate will most likely only be a temporary fix until the cement erodes again (however long it took from the driveway first being laid).
Best option for a permanent long term fix is to have it coated, although this would most likely be fairly expensive based on your meterage.
The concrete hasn't eroded it's how the grano blasted the surface. I'm just going to ask a grano today it always turns into a fight on here. Thanks to the blokes who gave useful advice
Why all the agro towards this guy? Why not just leave him to his question and let the posters with something useful to say interact with him.
That topic may have long life ahead.
Nice polished concrete becomes slippery when wet.
So next subject will be how to make good grip on slippery concrete. Some experience from those that made grip on their boards may help -but the few hundred meters could be expensive.
I suggest to buy kid good helmet first. Works both for slippery and aggregate concrete - and useful experience for future bike riding or surfing.
oh fck me that was a funny read. The doctor at his finest.
Settle gents...bahahahahaahahahahahaha.
Suggestion maybe... get your kid one of those 7 inch rubber wheeled skateboards and some pads etc. His balance will improve. Cheaper than redoing that much area of driveway. or just redo it, he's your son, fck what anyone else thinks.
The way the grano blokes get the exposed finish is to pour the concrete with whatever size / style aggregate mixed in.
Once the concrete is levelled off, they spray the surface with a retarding chemical, which soaks in to a depth of 4 - 5mm.
24 hours or so later [depending on ambient temp.] they hit the surface with a pressure washer - which neatly removes the retarded concrete and very effectively spreads it all over your walls, lawn and garden. 
Best option to lose the cheese grater effect would be to get the grano bloke back to recoat the main bit - or you could DIY with a bit of help from mates.
Wouldn't be hard to do with a mixer, bagged concrete [these days they are only 20kg], a trailer of brickies sand, another of fine cracker dust and a couple of cartons + Mrs Nathe and your mates better halves keeping the workers fed.
Don't leave it too long - stuff like this is better done before it warms up.
Don't forget to let your offspring leave handprints for future reference.
stephen
Think of your friendly postie before you polish it to a mirror like finish that resembles an ice rink at the first drop of rain.
Select to expand quotesn said..
Best option to lose the cheese grater effect would be to get the grano bloke back to recoat the main bit - or you could DIY with a bit of help from mates.
Don't forget to let your offspring leave handprints for future reference.
stephen
This ^^^^, you also need to mix in some bonder, it looks like white glue, probably is, it's designed for this type of application.
But if you live in an area that freezes from time to time, it might not last and will start to delaminate. If that happens, you could end up with the ugliest driveway on your street. But it would be cheaper than a grind job, so, pick your poison.
Dont grind it..it will become slippery with tyre marks appearing + depending if you live in hi humidity or hi rain fall
once you break the surface of concrete algae will become a problem without a sealer.
shot blasting could work,it has more none slip advantages but same problem as above without a sealer.
or patten pave it,,again costs.
their is no easy/cheap way.i have a BA in concrete 
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Select to expand quoteMastbender said..
you also need to mix in some bonder, it looks like white glue, probably is, it's designed for this type of application.
But if you live in an area that freezes from time to time, it might not last and will start to delaminate. If that happens, you could end up with the ugliest driveway on your street. But it would be cheaper than a grind job, so, pick your poison.
the "bonder" is called BONDCRETE, or possibly SILASEC, both available locally at Bumblings.
Freezing isn't regarded as much of a problem around these parts, concrete driveways often get used as back-up BBQ plates when the gas bottle for the barbie runs out.
So many contractors wash the slurry down drains and a few months later the owner wonders why it has backed up. Not an easy fix either.
