Visited the new city hall plaza in Springfield and the finish on the concrete is something else

Honestly, I was there yesterday and the main walkway has this perfect, almost glassy finish with zero marks. The crew must have worked in tiny sections because the joints are razor straight for about 200 feet. My buddy who works for the city said they did it all in one 14-hour day with a big ride-on trowel. It got me thinking about how they kept the bleed water so even on a slab that size. Has anyone here pulled off a pour that big and smooth without a single cold joint?

3 comments

3 Comments

ross.kevin1mo ago

One 14-hour day" for a slab that size is the key part. Your buddy might have meant just the finishing crew's shift. The pour and set would have started way earlier, maybe overnight. No way they placed, finished, and cured 200 feet of perfect concrete in a single stretch.

caleb_thomas931mo ago

Yeah that makes sense about the pour starting earlier. But what about the vapor barrier idea from @finleyw99? Could that actually let them finish it faster if the water came up more even?

finleyw991mo ago

Wait, is it possible they used a vapor barrier under the slab? I read that can really help control bleed water on big pours by stopping it from soaking into the ground below. If they had a super flat subgrade and that plastic sheet, the water would have nowhere to go but up evenly. That might explain the glassy finish without marks.