Introduction
The Heat-Box is used
for determination of the Adiabatic Heat of Hydration for concrete mixes.
The Adiabatic Heat of
Hydration is an essential input-parameter when making thermal analyses of
hardening concrete structures.
The system is based on
a semi-adiabatic measuring followed by a 3D-dimensional thermal analysis. The
analysis takes into account the heating of the Heat-Box itself from inside and
the loss of heat to the surroundings.
Before the Heat-Box
system is taken into use the software has to be calibrated. Calibration is done
by placing a container with app.
The result of the
calibration is the thermal properties of the insulation material in the
Heat-Box.
Measuring of Heat of
Hydration is done in the same manner just with fresh concrete instead of hot
water. A typical progress of the measured temperature is shown in figure 2.
This progress and the above mentioned thermal properties are the basis for the
thermal analysis which is resulting in assessing the Heat of Hydration. The
Heat of Hydration is expressed as the accumulated output of energy as a function
of the maturity (degree of hydration).
In both cases, also
the ambient temperature is registered. The progress of the ambient temperature
enters in the thermal analysis when calibrating and measuring.
The resulting
Adiabatic Heat of Hydration is shown in Figure 3.
The calibration
procedure is described in details here.
The procedure for
measuring Heat of Hydration is described in details here.
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Fig. 1 Decay of
temperature when calibrating |
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Figure 2 History of temperature when measuring Heat of Hydration |
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Figure 3 Resulting Adiabatic Heat of Hydration |
