@SolarCoordinates whatever, the guy mixing in this movie is aa noob anyway, you don't buy premixed concrete (to expensive) , but cement, sand and gravel. A simple rule for stron concrets = 1 part cement, 2 parts sand, 3 parts gravel .
Also prefered to add some additives to smoothen the mixture
@sjoerd1412 , denk een 6 uren, maar wel met middagpauze en wat bezighouden, effectief werk +/- 5u