Strengthening

I was in touch with the producer of my cement and was sent some lovely Cement performance curves!!
Buildcrete curve (general purpose cement)
Powercrete curve (a slightly quicker-setting cement)
Duracast curve (an even quicker setting cement)

These little beauties opened my eyes a little.

I knew that less water=stronger cement (see earlier post) but I didn’t realise the extent to which this mattered. For every 1 L of cement, I’m putting in 0.8L of water, so that its runny enough to work with. This is because I’m using fine sand, as well as coarse sand. This fine stuff is good because it fills voids between the coarser sand, but is bad because it is very thirsty; you need a lot of water when you use it..

So… I’m gonna reduce the fine sand content a bit. Although in one respect it will make the concrete panels weaker, I think this will be more than outweighed by the benefit of having to use less water.

Fingers Crossed!