Genleştirilmiş kil agregalı betonların ısıl özelliklerinin incelenmesi

Inefficient energy consumption and energy cost increase due to inadequate insulation of structures. These increases due to missing or incorrect insulation applications can be reduced by selection and production of construction materials with low thermal conductivity. The aggregates have a great importance in the production of low-density concrete. Aggregates can be obtained as natural or artificial. Expanded clays (EC), occur as a result of sudden exposure of the clay to high temperatures. With the emergence of the gases in chemical structure, gas-filled pores appear in structures. In this way, the volume clays increase between 1.5 and 6 times of their initial volume. The products such as lime, coke and fuel-oil are added to the clay mud for increase the expansion. There is no production of EC in Turkey and it is not widely used. In the studies, compatible relationships are determined between density and thermal conductivity. The great part of the consumed energy is used for heating of buildings. For this reason, production of building components from the materials having low thermal conductivity is extremely important. To reduce heat losses in buildings, coating of building components is applied as a method with very low thermal conductivity materials. Another method is to reduce the thermal conductivity of building components. In this study EC as aggregate were used in the concrete material as building components and thermal properties of the produced concrete were investigated. 0-2 mm, 2-4 mm and 4-8 mm grain diameter expanded clays were added to the prepared samples by weight of 20%, 40%, 60% and 80%. for prepared samples. Containing different grain size and proportions mixtures prepared as 12 different samples were poured into patterns suitable with meter probes. In the study CEM IV / B (P) 32.5 R-type pozzolanic cement was used. Samples were left to dry for 28 days. Densities of the samples were determined thermal conductivity and specific heat were measured and thermal diffusivity coefficient was obtained from these results. Measurement device performs measurements by using in accordance with DIN 51046. It was seen from the results that density and thermal conductivity decreased and the specific heat was observed to increase EC aggregate in grain size and weight. In this study, which was conducted to produce low density concrete, it was seen that the thermal conductivity of samples decreased on the other hand specific heat values increased depending on EC grain size and amount of aggregate material. Thermal conductivity was between 0.459 W/mK and 0.222 W/mK, specific heat capacity was in the range of 867 J/kgK to 2254 J/kgK, density was changing from 1810 kg/m3 to 531 kg/m3 and the thermal diffusivity was between 2.92x10-7 m 2 /s and 1.86x10-7 m 2 /s. A good polynomial relationship was found between the density and thermal conductivity. The correlation coefficient (R2 ) was obtained to be 0.994, 0.999 and 0.981 for the grain size of 0-2 mm, 2-4 mm and 4-8 mm, respectively. Compared to many other similar building materials, very low thermal conductivity of EC aggregate concretes can be considered as an important advantage.