Seven days is the normal minimum cure time, not 24 hours. Max strength at 28 days, but both 7 days and 28 days assume the concrete has undergone daily application of water. IMO the earliest you should take forms off is 48 hours, but longer is better. Dry pour is different from wet mix, so the more water you can give it early without surface erosion, the better.
Love seeing experiments on this. Seen a ton of videos. After seeing the first video with them messing around with gravel while screeding it, I knew I'll never do it like that. You simply add a top layer of gravel free mortor mix or sand/topping Mix concrete. Like 1/2" or so. It has the same rating as regular. 4000psi
Do you have any videos of your 21x14 slab or just the short video? Did it turn out ok? I can not find any videos on how to do a large slab. I was so hopeful you would show the whole process...
Still working on it. I got the 1st section 7'×14' done. I won't get to the next section for a bit due to the holiday. And some travel plans. It turned out okay. I think I can improve on the surface finish on the next section. I took so long fussing with the 1st one that it started getting late on me, then I got in a hurry to start watering. Structurally it seems fine. I have not taken off the forms yet, but have been walking on it. I will post video after the next section.. Hopefully with some improved results.
I appreciate the expirement because I had been wondering if using a trowel to finish was possible. I'm curious if troweling would have worked better after the first watering ...before it had time to set up.
Why wait to mag and trowel the other two? Once the surface dries up you cannot finish them. Those other two would need to be worked shortly after watering the first time but also would need a whole lot more water for those. Also, you'd need to cure a lot more before taking off forms.
Seven days is the normal minimum cure time, not 24 hours. Max strength at 28 days, but both 7 days and 28 days assume the concrete has undergone daily application of water. IMO the earliest you should take forms off is 48 hours, but longer is better. Dry pour is different from wet mix, so the more water you can give it early without surface erosion, the better.
Love seeing experiments on this. Seen a ton of videos. After seeing the first video with them messing around with gravel while screeding it, I knew I'll never do it like that. You simply add a top layer of gravel free mortor mix or sand/topping Mix concrete. Like 1/2" or so. It has the same rating as regular. 4000psi
This is genius!
Do you have any videos of your 21x14 slab or just the short video? Did it turn out ok? I can not find any videos on how to do a large slab. I was so hopeful you would show the whole process...
Still working on it. I got the 1st section 7'×14' done. I won't get to the next section for a bit due to the holiday. And some travel plans.
It turned out okay. I think I can improve on the surface finish on the next section. I took so long fussing with the 1st one that it started getting late on me, then I got in a hurry to start watering. Structurally it seems fine. I have not taken off the forms yet, but have been walking on it. I will post video after the next section.. Hopefully with some improved results.
I appreciate the expirement because I had been wondering if using a trowel to finish was possible. I'm curious if troweling would have worked better after the first watering ...before it had time to set up.
Why wait to mag and trowel the other two? Once the surface dries up you cannot finish them. Those other two would need to be worked shortly after watering the first time but also would need a whole lot more water for those. Also, you'd need to cure a lot more before taking off forms.
Just some friendly critique of the video. That purple text is way hard to read.
Good to know. I can adjust.
why not get it wetter the first time and mag float it then? can't float set concrete!