While the summer heat brings some personal fun in the sun, it can be problematic when pouring concrete. The hot weather speeds up the curing time of concrete and increases the likelihood of low cylinder breaks. Proper care and storage of your test cylinders can prevent a lot of headaches saving precious time and money.
Improper care of test cylinders makes them less representative of the in-place concrete. Cylinders are very prone to damage within the first 24 hours after the concrete has been placed. The cylinders should be kept in a moist 60 to 80 degree environment that is vibration free. Generally, if you are in the cylinder storage area and are comfortable, then the cylinders are probably in the right temperature range.
It can be logistically difficult to provide a place for proper storage of the cylinders but here are a few ideas.
· An insulated curing box with a high-low thermometer kept between 60 and 80 degrees is a good start. Depending on the temperature, you may have to add ice to keep it cool enough for the cylinders.
· A water tank where the cylinders can be totally immersed into water is another good way to keep your cylinders cool. This is the best method to prevent any moisture loss during initial curing.
· It is ideal to have a temperature-controlled jobsite trailer or room to store the cylinders. It’s important to remember that vibration has a negative impact on cylinders. The storage area for cylinders needs to vibration free and away from the work zone to prevent damage from earth moving equipment or just people walking by.
If you follow these quick steps you will have far fewer problems on your project that can trigger costly delays.