1 Basic principle and key points of ICC 1.1 Basic Principle The test method is designed to measure the heat of hydration of cement when mixed with water. The measurement takes place at essentially constant temperature, if the instrument and the measurement are well designed, therefore it is assumed to be the “isothermal heat of hydration of cement”. An isothermal heat conduction calorimeter (here called calorimeter) consists of a thermostatic heat sink upon which two heat flow sensors are placed. The sample is placed in an ampoule that is placed in an ampoule holder that is in contact with one of the heat flow sensors, and an inert reference is placed in contact with the other. The sample ampoule and the reference ampoule are thermally connected by heat flow sensors to a thermostatic heat sink. The output from the calorimeter is the difference between the outputs from the sample heat flow sensor and the reference heat flow sensor. A general scheme of a heat conduction calorimeter is given in Figure 1. However the actual design of an individual instrument, whether commercial or home-built, may vary. (…) Most part of the calorimeters can measure the heat of hydration of samples mixed outside from the instrument therefore the heat produced during the mixing is not measured. It is not easy to solve this problem designing a calorimeter provided with an internally mixing device having the proper efficacy. 1.2 Key points of ICC When performing ICC measurements on cement samples some key points have to be considered and correctly managed: – Constant value of the temperature of the thermostat; – Stability of the temperature of the thermostat all over the test duration; – Control of the maximum difference between sample temperature and thermostat temperature (isothermal conditions); – The baseline of the instrument (measured with an inert sample of similar thermal properties of test sample) should be both repeatable and stable; – Calibration of the calorimeter. The method currently used is based on the joule effect produced by a resistor feed with an electrical current; no standard material for the calibration is available for the time being; – Check that the ampoule is vapour tight enough (so that endothermic thermal powers of evaporation do not influence the measurements).

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PDF Pages	PDF Title
4	Contents Page
6	Foreword
7	Introduction
8	1 Basic principle and key points of ICC 1.1 Basic Principle Figure 1 — A schematic drawing of a heat conduction calorimeter
9	1.2 Key points of ICC 2 Normative references 3 Technical data sheets of available calorimeters Table 1 — List of Instruments considered for the analysis of technical data sheets
10	4 Experimental data
11	5 Calibration 5.1 Calibration of isothermal heat conduction calorimeters Figure 2 — A schematic drawing of the set-up for the simultaneous calibration of two calorimeters
12	Figure 3 — Schematic steady-state calibration
13	Figure 4 — Schematic of pulse calibration 5.2 Determination of the baseline 5.3 Open question
14	6 Final remarks
15	7 Scope and field of application 8 Terms and definitions
16	9 Apparatus 9.1 General
17	Figure 5 — A schematic drawing of a heat conduction calorimeter 9.2 Thermostat 9.3 Calorimeter technical parameters
18	10 Calibration 10.1 General Figure 6 — A schematic drawing of the set-up for the simultaneous calibration of two calorimeters
19	10.2 Steady state calibration 10.2.1 General Figure 7 — Schematic steady-state calibration 10.2.2 Calibration coefficient (ε) 10.2.3 Time constant (τ)
20	10.3 Pulse calibration 10.3.1 General Figure 8 — Schematic of pulse calibration
21	10.3.2 Time constant (τ) 10.4 Determination of the calorimeter parameters 10.5 Improvement of common calibration procedure 11 Sample 11.1 General 11.2 Test sample
22	11.3 Reference sample 12 Testing procedure 12.1 General 12.2 Method A – “External mixing”
23	12.3 Method B – “Internal mixing” 12.4 Measurement 12.5 Calculations
24	12.6 Result
25	Annex A (informative) Glossary A.1 Ampoule A.2 Ampoule holder A.3 Baseline A.4 Calibration coefficient A.5 Isothermal A.6 Reference A.7 Thermal power
26	Bibliography

Published By	Publication Date	Number of Pages
BSI	2014	28


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Status	Definitive
Pages	28
Publication Date	2014-06-30
ISBN	978 0 580 83044 0
Standard Number	PD CEN/TR 16632:2014
Title	Isothermal Conduction Calorimetry (ICC) for the determination of heat of hydration of cement: State of Art Report and Recommendations
Identical National Standard Of	CEN/TR 16632:2014
Descriptors	Cements, Heat of reaction, Calorimeters, Chemical analysis and testing, Mathematical calculations, Cement and concrete technology, Heat of solution, Heat measurement, Hydration
Publisher	BSI
Committee	B/516/12
ICS Codes	91.100.10 - Cement. Gypsum. Lime. Mortar

BSI PD CEN/TR 16632:2014

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