Anyone know about bitmac?
Discussion
We've just had a front drive / car forecourt done with bitmac. The firm doing it is well regarded and they recommended 10mm dense surface course bitmac, the job was part overlay and part base and top.
After only a week I am noticing stones are being lifted out the surface leaving small holes and stones kicking about the surface. This is where cars come in and turn left or right. If I do a 3-point turn, tyre marks are left on the surface and the point where the wheels have turned slightly has a few loose stones. In short, the surface doesn't seem at all resilient and I fear that after a few weeks, never mind years, the surface will be a mass of pock marks and loose stones.
Question: Was the product right for the requirement give that a lot of cars will be turning, is there a problem and if so what's the solution? The firm is coming out to look next week and I would like to be informed.
After only a week I am noticing stones are being lifted out the surface leaving small holes and stones kicking about the surface. This is where cars come in and turn left or right. If I do a 3-point turn, tyre marks are left on the surface and the point where the wheels have turned slightly has a few loose stones. In short, the surface doesn't seem at all resilient and I fear that after a few weeks, never mind years, the surface will be a mass of pock marks and loose stones.
Question: Was the product right for the requirement give that a lot of cars will be turning, is there a problem and if so what's the solution? The firm is coming out to look next week and I would like to be informed.
B17NNS said:
Have read that and it doesn't really answer the question. However other resources seem to suggest that 10mm is okay as a driveway surface.ATTAK Z said:
It's a bit like baking a cake ... if the mix isn't right or if it's cooked at the wrong temperature then the cake will be crap ... same with bituminous concrete ... too much binder/too little binder/wrong grading for the aggregate/laid too hot/laid too cold etc.
So assuming the problem worsens and we get loose stones / holes all over the place what's the solution? A 6mm overlay?I have to say that the appearance is a bit coarse too. It's a domestic environment and the bitmac extends onto a side path. It looks a bit too, well, coarse for the job. Not sure if it will improve when the gaps become filled with dirt and it fades a bit.
Eleven said:
ATTAK Z said:
It's a bit like baking a cake ... if the mix isn't right or if it's cooked at the wrong temperature then the cake will be crap ... same with bituminous concrete ... too much binder/too little binder/wrong grading for the aggregate/laid too hot/laid too cold etc.
So assuming the problem worsens and we get loose stones / holes all over the place what's the solution? A 6mm overlay?I have to say that the appearance is a bit coarse too. It's a domestic environment and the bitmac extends onto a side path. It looks a bit too, well, coarse for the job. Not sure if it will improve when the gaps become filled with dirt and it fades a bit.
If he argues then get an expert opinion and a lab test ...
... and a good solicitor
ATTAK Z said:
Eleven said:
ATTAK Z said:
It's a bit like baking a cake ... if the mix isn't right or if it's cooked at the wrong temperature then the cake will be crap ... same with bituminous concrete ... too much binder/too little binder/wrong grading for the aggregate/laid too hot/laid too cold etc.
So assuming the problem worsens and we get loose stones / holes all over the place what's the solution? A 6mm overlay?I have to say that the appearance is a bit coarse too. It's a domestic environment and the bitmac extends onto a side path. It looks a bit too, well, coarse for the job. Not sure if it will improve when the gaps become filled with dirt and it fades a bit.
If he argues then get an expert opinion and a lab test ...
... and a good solicitor
BigTom85 said:
10mm dense is ideal for a driveway, indeed we use it for estate roads.
Sounds like it was too cold before final compaction. Did they use whacker plates or a roller?
Ride-on roller.Sounds like it was too cold before final compaction. Did they use whacker plates or a roller?
Edited to add that we've still got a couple of roller marks and a puddle when it rains. Not deep but a puddle nonetheless.
Edited by Eleven on Thursday 11th September 22:30
As I highway engineer I maybe able to help out a little. In theory 10mm aggregate bitmac should be fine for what you need it for. For a simple on and off driveway it would be fine. However if there are lots of turning movements, 3 point turns, turning of wheels when stationary, the open grading for the 10mm will not withstand well and as would mentioned the aggregates will lift. Personally I would have gone for the 6mm but that's not the point here.
As mentioned 10mm is fine. So lets loot at what the issues can be.
Was the bitmac machine laid?? are hand laid i.e dumped then hand raked into place??
Was it rolled?? Bitmac needs rolling, 1 to compact the voids, and secondly to bed the surface aggregates. Temperature of laying is also a massive factor, if the material has been sitting on the back of a normal flat bed transit with a sheet of hessian over then your asking for trouble. This introduces different temperatures through the material, you want a constant. These are all factors effecting the performance for your new drive way.
If it was not rolled with numerous passes with a roller the aggregates will sit proud and lift out.
Was there different layers of construction or just 1 load of bitmac dumped and leveled across the driveway??
Do you have any photos??
As mentioned 10mm is fine. So lets loot at what the issues can be.
Was the bitmac machine laid?? are hand laid i.e dumped then hand raked into place??
Was it rolled?? Bitmac needs rolling, 1 to compact the voids, and secondly to bed the surface aggregates. Temperature of laying is also a massive factor, if the material has been sitting on the back of a normal flat bed transit with a sheet of hessian over then your asking for trouble. This introduces different temperatures through the material, you want a constant. These are all factors effecting the performance for your new drive way.
If it was not rolled with numerous passes with a roller the aggregates will sit proud and lift out.
Was there different layers of construction or just 1 load of bitmac dumped and leveled across the driveway??
Do you have any photos??
deanogtv said:
As I highway engineer I maybe able to help out a little. In theory 10mm aggregate bitmac should be fine for what you need it for. For a simple on and off driveway it would be fine. However if there are lots of turning movements, 3 point turns, turning of wheels when stationary, the open grading for the 10mm will not withstand well and as would mentioned the aggregates will lift. Personally I would have gone for the 6mm but that's not the point here.
As mentioned 10mm is fine. So lets loot at what the issues can be.
Was the bitmac machine laid?? are hand laid i.e dumped then hand raked into place??
Was it rolled?? Bitmac needs rolling, 1 to compact the voids, and secondly to bed the surface aggregates. Temperature of laying is also a massive factor, if the material has been sitting on the back of a normal flat bed transit with a sheet of hessian over then your asking for trouble. This introduces different temperatures through the material, you want a constant. These are all factors effecting the performance for your new drive way.
If it was not rolled with numerous passes with a roller the aggregates will sit proud and lift out.
Was there different layers of construction or just 1 load of bitmac dumped and leveled across the driveway??
Do you have any photos??
The material was delivered by proper lorry, raked out and rolled with a ride-on roller.As mentioned 10mm is fine. So lets loot at what the issues can be.
Was the bitmac machine laid?? are hand laid i.e dumped then hand raked into place??
Was it rolled?? Bitmac needs rolling, 1 to compact the voids, and secondly to bed the surface aggregates. Temperature of laying is also a massive factor, if the material has been sitting on the back of a normal flat bed transit with a sheet of hessian over then your asking for trouble. This introduces different temperatures through the material, you want a constant. These are all factors effecting the performance for your new drive way.
If it was not rolled with numerous passes with a roller the aggregates will sit proud and lift out.
Was there different layers of construction or just 1 load of bitmac dumped and leveled across the driveway??
Do you have any photos??
Here is an image of where cars turn into the forecourt.
Here is an image of where stones are being pulled out:
It is only minor at the moment, but it's at a point where cars will pass every time they enter the gates. Also in other places of high use a similar thing is happening and an increasing number of loose stones are kicking about.
I was anticipating a robust and durable surface, but this seems pretty fragile.
BigTom85 said:
I'd want it resurfaced, but realistically it will just get a patch and you will have joints to fail instead. That scabby area will become a pothole in no time at all.
A patch will be visible right?Also, there are many other areas like that. In fact the whole area looks "dry".
He won't be patching it.
Spudler said:
Having seen the pic I'd say it's down to bad workmanship.
Even compacted by a ride-on roller, if not a uniform thickness then there will be areas less consolidated than the rest.
The over all appearance of the work is difficult to capture on camera, but the texture is very "open" and dry looking. There are few fines in it. Also at the edges where it meets kerbs the finish isn't sharp - it looks like the council just resurfaced a B road. I wasn't hugely concerned about this, but now I am seeing it degrading I am more so.Even compacted by a ride-on roller, if not a uniform thickness then there will be areas less consolidated than the rest.
I think part of the problem may be that the estimator under-estimated the area and they needed to put down an additional truck's worth of base layer. I wonder whether they've tried to save money on the wearing course somehow? Is that a possibility?
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