Exploring empty space, using papermache and heat

Layering several concrete mixes can lead to a rather thick build up which might look in some cases very chunky and heavy. I want, however push my favourite materials. Hence I've been thinking about ways to give my concrete forms a more delicate flair. After all, I want to show fragility, inflammation, decline and unpredictability in my work. To visualise the vulnerability we can find ourselves in through an invisible illness, I would like to take my inclination to distress (tubular forms) in my work a step further now. I'd like to pierce the concrete or clay and, depending on perspective, take away or create empty space that becomes a form in itself. (Hepworth) This hopefully adds another dimension, creates interest or even tension that wants to be balanced out again.

Under the light of the inherent concept of tension and release, balance and vertigo... I use fire in order to distress the surface until holes appear.

To give the forms an inner structure and stability when attacked by my blowtorch, I experimented with paper mache. It's a very lightweight, strong material, especially when combined with concrete - and it burns... (taking inflammation literally)

So the thin layer of papermache would be covered in concrete slip and still look quite delicate. The spots that weren't covered in concrete, would burn away.

But I am one step too far already. I tried the technique on clay, first. 

Here's how I made my papermache:

papermache beads that were pushed into the clay, then burned away in the kiln

Fired result, added copper carbonate (left) to bring out the ragged texture of the holes.

The copper carbonate should turn a blackish green, fingers crossed!

The fired result where the copper carbonate turned the holes a blackish colour and accentuates the ragged texture of them

The concrete tests

casting a test tile adding paper beads, the hardened tile, the burned beads

weakened material, looks great, will run further tests

Bowl shapes

Here I added packaging beads, puffed plastic to my cement mix. I prefer the
paper beads as burning the plastic creates toxic fumes and it the foamy plastic 

seems to gather a lot of air bubbles which weakens the concrete too much. 

Looks intriguing, though.