External concrete dusty / breaking up

Just moved and the concrete outside is dusty and when hosed it's just breaks up in a couple of places......clearly whoever did it the mix was not right

I haven't got cash to be doing the whole concrete area for the time being and was possibly looking at some sort of stabilisers to slow down it. They are stabilisers on ebay http://pages.ebay.com/link/?nav=item.view&alt=web&id=181107512689 but guy isn't emailing me back if this if for external use

If this is no good can anyone recommend an external stabiliser to stop the dusty surface

Thanks.

I guess you could try driveway sealer, this sort of thing on a small area first.
Certainly for outdoor use, although designed mainly to stop stains getting into the drive.

http://www.screwfix.com/p/no-nonsense-path-patio-driveway-sealer-5ltr/49885