Before erecting tilt-up concrete panels, you must allow them to gain enough strength to withstand lifting stresses. Erecting panels before they achieve the proper strength can lead to damage, costly repairs and even serious accidents.
Because concrete gains strength more slowly in cold weather and more quickly at higher temperatures, curing time alone isn't an accurate method for determining in-place concrete strength. Only reliable testing can produce accurate estimates of in-place concrete strength. The most common testing method makes use of field-cured cylinders. Unlike laboratory-cured cylinders that are used for acceptance of a concrete mix, field-cured specimens are left onsite until testing. To provide a good estimate of in-place concrete strength, however, field-cured cylinders must be handled properly.