Crumbling concrete in yard

[Perissa]

I have a section of concrete in the yard which has started crumbling. I notice it particularly when I sweep it when random small stones come loose.

Is there anything I can pour on it to strengthen it again?

I know long term it will need to be dug up and replaced

 

[Bluecat45J]

for a short term quick fix, mix a wet mix of cement and sand with a PVA glue or cement sealant and pour over area and level off ( as a type of screed, not to smooth otherwise would become slippery,) this will stop frost getting into it further, but pick a nice day as takes a while to go off and will become very dusty when cured if it gets rained on and will crack if not cured and get frost on it.
hope this helps

 

[Daisy11]

I agree with above but becareful not to make concreat to weak as Its more and likely to crack too

 

[doferdude]

I have worked on many a concrete drive, repairing potholes. If we are talking potholes, then this is your cure. If you are talking huge sections, then sorry for wasting your time!
If you have a angle grinder, a big hammer drill (with hammer only function and a chisel to fit) and a rammer of some description, here's what to do: Cut a rectangle around the crumbling concrete about 10cm deep, chip out the inside of the rectangle with your drill (10cm deep throughout) and refill. Make sure you ram it down hard, (its just good practice) I use roofing felt sealant to seal the edges when the concrete has dried. (A bit redkneck I know!)
Concrete thinner than 10cm will crumble...crumble and crumble some more. However if you can get a nice clean edge 10cm deep it is infinitely stronger and may save you digging up much bigger sections.
That is what I would do, but personal preference is king! I must be honest though, pouring concrete and sand over the top will not last you much more than a year where as digging a minimum amount out, having a clean edge (clean edge is essential) and back filling will last as long as any other method.
All said, it is much easier to tip a quick mix down, just not as enduring! Hope that helps!
P.S. If you want to do it this way, then check out This to get your materials correct (sand, gravel, cement, water) Make sure you input your w, h and d in meters. Then press 'volume' and the 'quantities'.