All recommendations are welcome. In particular how to vibrate a two part mold without it breaking apart. I did not weigh the mix and water, but i suspect i used too much water. Also added about 2% plasticizer.
Thank you for the elaborate response. The second batch is now vibrated a whole lot more than the first one and i weighed the mixed beforehand. It’s just a premixed bag for setting posts i’ve used. 0-8mm. It’s really a pleasure to see the concrete vibrate into place. I am curious whether i’ve now also vibrated the pour down between the two parts of the mold too… We’ll see in a few days i guess.