Pouring and Curing the Panels

Its amazing (for me at least!) to think that despite having spent 3 years at university studying Civil Engineering, and spending about 1/3 of that time learning about the wonders of Concrete, I’d only actually made the stuff once before. And so with a little trepidation I began casting the Textile Concrete Panels…

Just to warn you, if you’re not that interested in Concrete (ha ha, as if!) then read no further!

Concrete has 3 ingredients which you mix together: Cement, Aggregate and Water. I always used to get the words Concrete (the end product) and Cement (an ingredient) mixed up, but I digress… The Cement and Water react with each other over time and become hard. Aggregate is basically stone or sand, (both of which are a lot cheaper than Cement) and provide bulk to the Concrete. The ratio of Cement, Aggregate and Water you mix has a HUGE effect on the strength of the finished Concrete. Briefly…

Cement

The more there is, the stronger the Concrete, but remember, it’s the most expensive ingredient!

Water

It’s a bit like Goldilocks and The Three Bears. You gotta get the porridge just right!

Too much water: Makes the mix runny and easy to work with BUT as the mix dries, lots of air gaps are left AND the reaction between the Cement and Water is too quick so you get a WEAK CONCRETE. :o(

Just enough water: The mix is easy to pour AND there is enough Water for all the Cement to react fully so you get STRONG CONCRETE. :o)

Not enough water: The mix is stiff and so can be hard to work with AND there is not enough Water to react with all the Cement, so you get a WEAK CONCRETE. :o(

Aggregate

For the Textile Concrete Panels I need a runny mix that it will seep between the fibres of the textile, so I've been using use a fine Aggregate (sand). At the moment I've had to use a combination of fine sand from a nearby riverbank, and coarse sand from a big pile that happens to be lying around near to where I've been working.

I've been experimenting with different mixes to find the right Cement:Aggregate:Water mix, which takes time, but once I know these mixture ratio’s, the rest is easy! (I hope) :o)

Curing the Concrete

Once mixed and poured into a mould, you need to ‘Cure’ the Concrete. This is a way of slowing down the reaction between the Water and Cement in order to make the finished Concrete as strong as possible (anyone remember growing crystals at school, cos its got something to do with that). It was a surprise to me just how important the Curing process was, but after writing almost a page on how and why I cured the panels I realised was a bit too much to include in this blog, so if you really want to know, please leave a comment!

PHEW!