Here, the temperature is being taken after concrete placement, but ideally it should be taken prior to placement to respond to temperatures outside of a specified range. The thermometer is placed to provide at least 3 inches of concrete around the
inserted stem and left in place a minimum of 2 minutes and until the temperature has stabilized.

Start taking temperature measurements of the concrete (per ASTM C 1064) within 5 minutes after securing the remixed composite. The thermometer should be accurate to 1° F. The concrete should be in a wheelbarrow or other suitable receptacle that will permit insertion of the thermometer so that at least 3 inches of concrete surrounds the stem. As long as sufficient concrete surrounds the thermometer in your sample, it should remain inserted for a minimum of 2 minutes while all the other tests are being conducted. After the 2 minutes elapse, the test is complete once the reading remains stable to within 1° F.

Temperature measurements can also be taken in the transporting vehicle or within the forms as long as 3 inches of concrete surround the thermometer. Measuring concrete temperature in the forms (see photo) is not really a recommended practice since the "toothpaste" is already out of the tube. But if the measurement was missed in the rush of getting everything else done, taking the measurement post-placement will suffice.

Testing tip: A common mistake many people make is to remove the thermometer to read the temperature. Be sure to read the dial while the thermometer is still inserted into the concrete.

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