Laying tarmac on concrete base

Farmer_Giles_3

Very similar to an existing thread "tarmac driveway" but I think my question has a slightly different focus.
The drive at the side of my house and the yard behind the house is surfaced with tarmac laid (25 years ago) on a reinforced concrete base which was part of an old farm road and farmyard. There is now a lot of loose aggregate on the tarmac surface which sticks to footwear and transfers to the house. Also algae (or something!) grows on the loose aggregate and looks unsightly.
Does anyone know of any process please, by which I can obtain a hard smooth tarmac surface without starting from scratch?
I think that taking up 8 inch thick reinforced concrete would be prohibitively expensive and anyway I think it would seem wasteful to do this. I could remove the existing tarmac but it does seem that the base-coat at least, is still stuck quite firmly onto the concrete.
The present surface is about 6 inches below the dampcourse of my house, so there's limited scope for raising the level of the drive by adding a lot of new material on top. There is a sort of French drain 6 inches wide and filled with chippings, separating the house from the drive so maybe? I could raise the level a little if necessary.
I'd very much appreciate any advice members can offer on the best way to deal with this problem.

Alfrescodave

I would suggest that you contact your local registered "drive" installer (not the guys who just happen to be in the area and wondered if you wanted your drive doing).He would be able to lay tarmac on top of the exisiting material, if as you say the base coat is still quite firm. What he should be using is a tack-coat which is usually a water/bitumen emulsion which is sprayed or brushed on and provides additional addhesion between the old and the new layers.

Farmer_Giles_3

Thanks Alfrescodave for your prompt reply, I'll try to contact the firm who did the original job, if they're still in business.