On concrete delivery time, how long do you have before concrete should be poured?

On concrete delivery time, how long do you have before concrete should be poured?

• A. 2 1/2 Hours
• B. 2 Hours
• C. 1 1/2 Hours
• D. 1 Hour

Answer: (C)

Concrete has a limited pot life after mixing—the time you can place and finish it before it begins to stiffen. For most ready-mix concrete, that workable window is about one and a half hours (90 minutes). This window gives you enough time to place, spread, consolidate, and finish the slab after delivery. If you wait longer, the mix loses workability, may segregate, and finishing becomes difficult, increasing the risk of cold joints or weak areas. Weather and mix specifics matter: hot conditions shorten the window, cooler conditions can extend it somewhat. If more time is needed, retarders can extend the window, but as a general rule, 1 1/2 hours is the standard guideline.

Concrete has a limited pot life after mixing—the time you can place and finish it before it begins to stiffen. For most ready-mix concrete, that workable window is about one and a half hours (90 minutes). This window gives you enough time to place, spread, consolidate, and finish the slab after delivery. If you wait longer, the mix loses workability, may segregate, and finishing becomes difficult, increasing the risk of cold joints or weak areas. Weather and mix specifics matter: hot conditions shorten the window, cooler conditions can extend it somewhat. If more time is needed, retarders can extend the window, but as a general rule, 1 1/2 hours is the standard guideline.