1. Sampling Concrete.
1.1 The temperature of freshly concrete may be measured
in the transporting equipment provided the sensor of the temperature measuring
device has at least 3 in. [75 mm] of concrete cover in all directions around
it.
1.2 Temperature of the freshly mixed concrete may be
obtained following concrete placement using the forms as the container.
1.3 If the transporting equipment or placement forms are
not used as the container, a sample shall be prepared as follows:
1.3.1 Immediately, prior to sampling the
freshly mixed concrete, dampen (with water) the sample container.
1.3.2 Sample the freshly mixed concrete in
accordance with practice C 172, except that composite samples are not required
if only purpose for obtaining the sample is to determine temperature.
1.3.3 Place the freshly mixed concrete
into the container.
1.3.4 When concrete contains a nominal
maximum size of aggregate greater than 3 in. [75 mm], it may require 20 min
before the temperature is stabilized after mixing.
2.
Procedure.
2.1 Place the temperature measuring device in the freshly
mixed concrete so that the temperature sensing portion is submerged a minimum
of 3 in. [75 mm]. Gently press the concrete around the temperature measuring
device at the surface of the concrete so that ambient air temperature does not
affect the reading,
2.2 Leave the temperature measuring device in the freshly
mixed concrete for a minimum period of 2 min or until the temperature reading
stabilizes, then read and record the temperature.
2.3 Complete the temperature measurement of the freshly
mixed concrete within 5 min after obtaining the sample.
3.
Report.
3.1 Record the measured temperature of the freshly mixed
concrete to the nearest 1°F [0.5°C].
4 Precision and Bias.
4.1 The
precision and bias of this test method have not been determined. A precision
and bias statement will be included when sufficient test data have been
obtained and analyzed.
