How to repair cracks in base for plank? [Images]

[Bordsduk]

Hello!
I have some cracks on a pedestal that is cast around part of the property. On the pedestal, fittings are cast in as mounts for posts that hold a fence. At this particular corner, the fence is an outer wall of a (cold) storage room, which means I can't see the other side of the pedestal. When you tap on the section between the cracks, you can hear that it is hollow.
I'm not too worried about the strength of the pedestal itself, but my main aim is to seal the cracks to avoid frost damage and prevent the problem from worsening.
Since I am completely a novice at casting, I wonder how best to do this? I would prefer not to redo this in a few years.

My first thought was to fill with expanding concrete, but then I read that expanding concrete is very runny and would probably just run off. Can't you mix it thicker to make it stay better? Because I suspect that something expanding is necessary to prevent new cracks from forming in what you just cast?
Do you need to try to insert some reinforcement into the cracks? Chicken wire or similar?

In some other places, the concrete has chipped off and exposes the rebar (due to the rebar being too close to the form during casting?), there I planned to use concrete filler, guessing it’s not suitable for the cracks?

Thanks in advance

 

[Stefan1972]

Let it be instead and buy some baseboards and screw them in. If it's poorly cast and it starts to rust at the reinforcement and crack apart, it's probably futile to try to do something permanent that lasts over time. Then it might be easiest to just cover it up and perhaps simultaneously avoid water penetration from the outside.

 

[Bordsduk]

Thank you for the response, but baseboards will look strange at the finish and corners.
It will probably have to be a spackling solution and hope that it takes many years before it needs to be redone.