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All materials have different and unique thermal properties that determine how the temperature changes when a material is subjected to a temperature difference. This study was intended to investigate the thermal properties of a polymer called Polyurethane, focusing on anti-seepage and anti-abrasion polyurethane. The thermal conductivity and heat transfer coefficient of cold polyurethane specimens have been calculated by capturing the infrared signature using a FLIR T1030Sc Infrared camera and comparing the results with simulated results. The simulations were carried out in MATLAB®, and the solution is based on the Heat equation. This paper describes the driving mechanisms behind the Heat equation and how the approximated solution to the Heat equation is obtained by discretizing through a forward-time central-space (FTCS) finite-difference method. The results reveal that the heat transfer coefficient for anti-abrasion Polyurethane is almost four times that for anti-seepage Polyurethane. The thermal conductivity for the respective has a difference of a factor of two. A good agreement between the experimental and the numerical study was achieved. This study is helpful for the potential use of polyurethane material in Arctic regions either as a coating material for pipes or as a sealant in the oil and gas industry. [ABSTRACT FROM AUTHOR]

Global warming may induce an increase of active layer thickness in the Arctic region. The freezing and thawing of the active layer can damage infrastructures such as roads, railways, and embedded pipe lines in cold regions. A few methods, however, have been proposed to characterize the active layer. The objective of this study is to evaluate the characteristics of the active layer by laboratory and field tests, especially using the instrumented dynamic cone penetrometer (IDCP). Geographical and geological characteristics of Ny-Alesund, Svalbard are introduced, and the geotechnical properties, microstructure observations, and thermal properties of the Ny-Alesund soils are investigated. In addition, subsurface temperatures monitored for a year are discussed. The IDCP, which is able to measure the energies transferred into the rod head and the cone tip, is applied to the evaluation of the strength variation and the thickness of the active layer in Ny-Alesund. During dynamic penetration tests, the IDCP can produce profiles of the corrected cone tip resistance as well as the dynamic cone penetration index (DCPI). The results show that the active layer thickness estimated from the DCPI and corrected cone tip resistance profiles is approximately 1700mm. Furthermore, the bottom of the active layer significantly corresponds to that estimated by the maximum ground temperature profile with a soil thermal diffusivity of 5.5·10−7 m2·s−1. This study represents the characteristics of Ny-Alesund soils investigated with a variety of laboratory tests, and suggests that the IDCP may be effectively used for active layer characterization. [ABSTRACT FROM AUTHOR]

• Effect of waste perlite and activation by jet mill on structure of cement paste is revealed. • Decrease in density and heat conductivity of plaster mortar is established. • Standard physical properties of plaster mortars are due to improved structure of cement paste. • The superplasticizer reduce the segregation of the cement-perlite mix. • Technology for production of low-density plaster thermal insulation mix was developed. The direction of many leading states is aimed at the development of the Arctic, so the creation of new generation thermal insulation materials is given priority. The novelty of the paper is to identify the scientific patterns of the influence of binder composites based on Portland cement and waste of expanded pearlite sand during joint jet grinding on the hydration mechanism and the structure of the plaster mortar. The grinding of heat-insulating binders in ball, vibration and vortex jet mills was studied. The features of hydrated phase formation and hardening of modified binders were studied taking into account the chemical, structural and morphological features of perlite wastes. Besides, the microstructural, morphological and thermal properties of the hardened binders at 28 days of curing were determined. For the first time, the scientific data were obtained on the properties of modified heat-insulating binder and plaster mortars based on it, obtained by mechanochemical jet activation. The results indicate that the jet activation of the modified binder based on Portland cement, waste from the production of expanded perlite sand and superplasticizer, contributes to the improvement of the physicomechanical properties of 28-days hardened binder: the compressive strength of 84.2 MPa and density of 2100 kg/m3. Based on the developed modified binder, the effective heat-insulating plaster mortars with heat conductivity of 0.051–0.059 W/(m·°C), a density of 240–260 kg/m3 and a compressive strength of 1.3–1.43 MPa were obtained, which meets the requirements. Technological route for the production of low-density plaster thermal insulation mix was developed. [ABSTRACT FROM AUTHOR]