Mixing postcrete and ready mix concrete

[Saifu]

Got just 2 layers of a rustic garden wall to patch up just 1m wide. Made of broken pieces of pavement slabs 50mm thick. Mortaring about 1 cm thick layer with same thickness aggregate thrown in for strength. Got maybe 3 or 4 handfuls wickes ready mix mortar bag left, but maybe little short to finish. Can I mix some left over postcrete to complete the job?
Questions on my mind:
1. Will it affect the strength?
2. Will it set?
3. Will chippings in post mix be too big?

 

[Nige F]

1 probably not... 2 yes...3 fine aggregate as I remember - have a look postcrete goes off quick.

 

[Saifu]

Yes you're right the bags go rock hard after some time. I didn't open the bag for that reason to check the aggregate. So is postcrete more like concrete because it is missing the sand portion? If so would that on its own be more brittle? Should I add some sand to balance it out?

 

[bsr]

Postcrete is a very fine concrete with rapid setting cement. It's generally got a lot of sand and not much aggregateso will hooefully be fine to use as is.