Influence of Temperature Difference on Thermal Conductivity of Lightweight Mortars with Waste Aggregate

摘要

The temperature on both sides of a wall partition influences the heat flux and thermal conductivity of a wall. Therefore, an analysis pertaining to the impact of temperature difference and set temperature values on the thermal conductivity on both sides of the considered samples was conducted. Different external and internal temperatures were obtained (using cooling and heating plates) in Bock Fox 300 apparatus. In the first analysis, the temperature differences on both sides of wall partitions were: (AT) = 10, 15, 20, 25 and 30 (°C), assuming that the external temperature equals 0°C, while in the second analysis, where the temperature was altered from - 15 to +5 (°C), constant difference amounting to (AT) = 10 °C was maintained on both sides.Lightweight mortars with 5 and 15 (%) PVC and woodwork waste addition were used in the study and analyses. A relationship, in which the thermal conductivity coefficient λ increased along with the external temperature, was observed during the study. By changing the temperature in the range from - 15 to +5 (°C), a 5-7 (%) increase in the λ coefficient value was obtained. Additionally, it was observed that a drop in the λ coefficient occurred with an increase in the temperature difference on both sides of the considered sample. In the case of temperature difference ranging from 10 to 30 (°C), the value of the λ coefficient dropped from 11 to 22 (%). It can be observed that the addition of waste aggregate leads to a reduction in the thermal conductivity coefficient in every recipe.