Help identifying hardcore

[dave_104]

Hi,
I've got garden people laying down some pathways, and the hardcore they're using is causing me a little concern. I wanted to identify what it is and if it's suitable for the job. They reckon it'll go rock hard when dried, and called it clunch (or something like that!). It has a chalky appearance and seems like clay in there too. It's laid on a weed sheet and has been whackered down but still it has a spongy feeling. I appreciate it's rained a lot recently and may not have dried out much though.
The top surface will be compacted gravel self-binding (not the resin one).

(I thought this was more of a building topic rather than a gardening one).

Thanks
Dave

 

[^woody^]

That's not hardcore. Looks like dust with lumps

 

[Mottie]

I thought this was a thread for Andy.

 

[JohnD]

I have an idea clunch is crushed chalk with added stone. It can be moulded and beaten down to make houses rather like cob. It will be a regional practice so say where you are.

Are you in a chalky area?

Will the top layer be hoggin? I've had that and very durable but may need re-levelling after 50 years.

 

[dave_104]

Thanks John that makes a lot of sense now and after looking up clunch and cob walls it seems a lot of churches are built from it (?) and the material is common in eastern England which is where I am.
Yes top layer will be hoggin with a mixture of fines, and will be whackered down without resins.
Lasting 50 years is good with me, I’ll be well gone by then!