Still not sold on using accelerator in cold weather pours

I watched a crew in Denver last month dump a ton of calcium chloride into a 30 yard slab because temps dropped to 28. The surface looked great for about 6 hours, then it spiderwebbed like crazy. Has anyone else had that kind of reaction with accelerators on a big flatwork job?

3 comments

3 Comments

hannah32011d ago

Nah, sounds like they just screwed up the mix.

shane_hayes11d ago

Agree completely, that mix sounds like someone just left the treble and bass knobs where they fell. Had a buddy who recorded an album once where the vocals were so buried you could barely hear them over the guitar, total waste of a good take. Probably just rushed the whole thing instead of taking the time to balance it out right.

christopherw3411d ago

The calcium chloride was probably reacting with sulfates already in the mix, that can cause the gel to set up too fast and then crack under its own tension. I'd guess the concrete was also too hot when it hit the forms, since that batch was likely heated to compensate for the cold. Did the crew check the concrete temperature before placing, or just dump the accelerator and hope for the best?