Abstract: “This paper investigates the thermal properties of structural lightweight aggregate concrete. Different types of concretes with four types of lightweight aggregates and several water/cement ratios were prepared. The strength classes of the produced lightweight aggregate concretes ranged from LC 16/18 a LC60/66, whereas the density classes ranged from D1.6 to D2.0. A normal weight aggregate was also used as reference. The impact of the concrete constituents on thermal conductivity, thermal diffusivity and specific heat was assessed by a modified transient test method and relations between those thermal properties and both density and water content of concrete were established. A significant exponential correlation between thermal conductivity and density of concrete was achieved. On average, thermal conductivity decreased about 0.6% per each 1% increment in aggregate porosity, 8.3% per each 50 L/m3 increment in coarse aggregate volume and 3-9% per each reduction of 1% by weight in water”

Keywords: lightweight aggregate concrete, normal weight concrete, thermal conductivity, thermal diffusity, specific heat