The Effect of Using Naphthalene and Local Soil with Concrete Mixture on Thermal Conductivity, Case of Mafraq City – Jordan

This study explores the effect of direct incorporation of different ratios of naphthalene with soil into the concrete used in Mafraq-Jordan on the thermal conductivity of concrete mixtures. The methodology involved testing 72 concrete cube samples. The basic samples were prepared only from a mixture of water, silica sand, and cement without additives. The additives of local soil and naphthalene of different ratios: 2.5%, 5%, 7%, 10% and 15%, were added to the tested samples. The samples were classified into two groups in terms of size and dimensions; 36 cubes with 5×5×5 cm were tested only for thermal conductivity, and 36 cubes with 3×3×3 cm were tested for compressive strength and thermal conductivity. All samples were tested after 28 days of casting, according to the concrete standards. The results show that adding naphthalene and soil to the cementitious mixtures substantially decreases the thermal conductivity of concrete elements. A reasonable reduction in thermal conductivity was achieved compared with the basic case samples. However, the compressive strength of samples remained within the acceptable values from the stand point of structural engineering. This enhancement in the thermal properties of concrete can be applied in building systems as concrete blocks used in internal and external walls.