Glue or similar to stick composite stone?

[RrogerD]

I've a 1980s Bovis property with composite-stone external window cills. Over the years a crack has formed, giving rise to water ingress and now of course the re-bar inside is rusted, expanded and the whole cill is breaking away. I've removed the loose pieces and released all of the wood-lice and other gunge.

How do I go about re-affixing it all back together please? Ideally I'd have thought some sort of resin glue which I could use to hold the pieces in place and then fill the remaining surface cracks.

Is simple yellow coloured mortar the way to go instead? I'm concerned that the thickness of the mortar would cause the pieces to be mis-aligned from where they should be.

TIA

 

[Tigercubrider]

A sculptor that I knew recomended arlodite (or similar) when I asked the question "what if you knock off the wrong bit"?
Suppose it depends if you have all the bits

 

[EddieM]

Wouldn't the composite have been formed with epoxy resin?

 

[RrogerD]

I suppose actually it is a concrete cill of some description. I presume, poured into a mould with rebar formed to the desired shape and profile. Not sure if this makes a difference?

 

[Deleted member 174758]

The guys we had to repair on the current project (a large mill refurb) and even replaced stone lintels and parapet capping stones used a mixture of what looked like ground stone, pigment and epoxy which was applied, worked, smoothed and polished with plastering tools. Some pieces they even cast on site. Fascinating process to watch.