BS 196-9:2010 pdf download – Methods of testing cement Part 9: Heat of hydration — Semi- adiabatic method
4.3 Platinum resistance thermometers, for the reference calorimeter and each test calorimeter, having a minimum range 19 °C to 75 °C. If the conductors of the electrical resistor are made of copper they shall have a sectional area not greater than 0,25 mm 2 in the part which passes through the stopper. If they are made of another metal the total thermal resistance per centimetre of conductor shall be greater than 0,10 K⋅mW -1 (thermal resistance equivalent to that of a copper conductor with a sectional area of 0,25 mm 2 and 1 cm in length). The thermal output of the thermometer shall not exceed 3 mW. Direct current supply, which constitutes a power input, shall be avoided if the thermal output exceeds 0,2 mW. It is advisable to ensure the accuracy of the overall temperature measuring and recording equipment. The temperature of the test sample shall be measured to an accuracy of ± 0,3 °C. Where the calorimeter is calibrated in situ with the conductors used for the tests of heat of hydration, the total sectional area of the conductors will be a maximum of 0,80 mm 2 (four wires 0,5 mm in diameter), but shall be such that the coefficient of heat loss of the calorimeter is less than 100 J⋅h -1 ⋅K -1 for a temperature rise of 20 K (see A.3.1.1). The protective sheath of these conductors shall be made of a material having a low thermal conductivity.
4.4 Mortar box, consisting of a cylindrical container fitted with a cover, having a volume of approximately 800 cm 3 , designed to contain the sample of mortar under test. The mortar box, discarded after each test, shall be impermeable to water vapour. This shall be checked in use by weighing the mortar box after each test (see 5.2.3). It shall be made of electrically counter welded tin plate of nominal thickness 0,3 mm; have a diameter of approximately 80 mm and a height of approximately 165 mm. Its height shall be designed to provide an air space of approximately 10 mm between the top of the mortar box and the stopper. The lid of the mortar box shall be fitted with a central thermometer pocket in the form of a cylindrical pipe, closed at its base. The internal diameter of the pocket shall be slightly greater than that of the thermometer. Its length shall be approximately 100 mm to 120 mm and enable it to extend to the centre of the test sample.
4.5 Temperature recording apparatus, capable of recording the measurements taken by each thermometer.
4.6 Mortar mixing apparatus, conforming to EN 196-1.
5 Determination of the heat of hydration
5.1 Laboratory The laboratory where the mortar is mixed shall be maintained at a temperature of (20 ± 2) °C. The room where the test is carried out shall be maintained at a temperature of (20,0 ± 1,0) °C. The measured temperature of the reference calorimeter shall be considered to be the ambient temperature and shall be maintained during the test within ± 0,5 °C. The distance between each of the calorimeters shall be approximately 120 mm. The velocity of the ventilation air around the calorimeters shall be less than 0,5 m⋅s -1 . When several tests are being carried out simultaneously, at least one reference calorimeter shall be provided for every six test calorimeters; where several test calorimeters are used with one reference calorimeter, a hexagonal arrangement shall be used with the reference calorimeter in the centre.
5.2 Procedure 5.2.1 Mortar composition The composition of the mortar shall be in accordance with EN 196-1 and the test sample shall have a total mass of (1 575 ± 1) g. Each batch of mortar to be mixed shall consist of (360,0 ± 0,5) g cement; (1 080 ± 1) g sand from a sample of CEN standard sand complying with the requirements in EN 196-1; and (180,0 ± 0,5) g distilled or deionised water.