Title : EXPERIMENTAL STUDIES AND COMPARATIVE ASSESSMENT OF TEMPERATURE RISE DUE TO HYDRATION OF CEMENTITIOUS MATERIALS IN CONCRETE
Authors : K C Tayade1, N V Deshpande2 and A D Pofale3
Publication : 23 - 26 October 2013
Volume :
Pages :
Price : 250
Abstract : The paper deals with the experimental studies of temperature rise in concrete of prototype structure. The actual temperature rise was measured by embedding thermo couples – resistance temperature detector (RTD) in the structure during concreting. The measurements were taken at 2 identical locations with same cross section by inserting 3 thermo couples (TCs) at each locations totaling to 6 in all. The measurement of temperature readings were taken manually by electronic recorder at every hour up to 7 days and the frequency was increased to 3 hrs and 6 hrs after 7 and 14 days respectively, the measurements were taken up to 28 days and beyond but restricted to 28 days in this reporting. The temperature at the time of insertion i.e. initial/starting temperature was noted and maximum temperature reached, the time to reach peak temperatures was recorded. The plot of time-temperature demonstrated the actual temperature rise, its trend both increasing and decreasing wherein all the thermal effects in and on the concrete such as effects of exothermic reaction of hydration of cement, conduction, convection and thermal properties of concrete such as specific heat, thermal conductivity, diffusivity and so also the external factors such as ambient temperature, humidity, wind speed, solar radiation, curing and form removal have played their role and the resultant was the actual temperature reached at that point where the measurements have been recorded by embedded TCs. The comparison of the actual measured temperatures made with the options available to predict maximum concrete temperatures by empirical formulas such as PCA method and adiabatic temperature rise curves as published in ACI committee reports showed that the actual measured temperatures were less than those predicted. The derived polynomial equations for the time-temperature record with strong correlation coefficient (r) values could be used to predict the early age temperature rise and for the temperature assessment at any time after concreting, albeit for the structure with similar geometry, cement content, ambient temperature and environmental conditions