Anyone know concrete mix design?

[pinkpanda3310]

Cool! Interesting hearing the result and your perspective on it brainy. I am surprised how light the first batch turned out. I guess the result might seem poor given the target 50mpa but you acheived a light weight concrete with standard 20-25 mpa, using plastic no less! I'm sure there has got to be a market for that in future with today's recycling attitude. I recall seeing bessa blocks (large bricks) made with syrofoam balls (bean bag beans) to make them light and easier to handle. Sounded like a fun project anyway (not everyones cup of tea, I know, but thanks for sharing).