engleski

Analysis of thermal properties of cement paste during setting and hardening

An experimental investigation is made in order to study changes of thermal properties of hardening cement paste. Using a hot disc principle for determination of thermal properties, specific heat capacity, effusivity and thermal conductivity are analyzed during first 4 days of hydration. Specific heat capacity value changed only slightly during hydration. Thermal conductivity decreased with the progress of hydration 20% compared to initial value. Hydration process was monitored using ultrasonic pulse velocity (UPV) test. A discussion of results is made taking into account porous nature of cement paste and transformation of liquid and hardened phases i.e. water and clinker minerals, into hardened structure. The motivation for conducted research is improvement of numerical models for calculating temperature changes in mass concrete structures using hydration dependant thermal properties. Also, another field of application could be the quality control of cement based materials.

Thermal conductivity; Ultrasonic pulse velocity; cement paste; non-stationary method

nije evidentirano