Increasing thermal stability of the roads in cryolithic zone

Abstract

Automobile roads in cryolithic zone in disctinctly continental climate conditions are subject to significantly greater adverse thermal impacts, such as high diurnal temperature variations, than similar structures in milder climates. This requires higher expenses on exploitation and maintenance of the automobile roads. It is possible to mitigate these negative impacts of rapid temperature changes, reducing maintenance costs and improving safety of road use, through application of thermal protection.This contribution explores protection of road structures using materials with high thermal stability indicator within the constructive layer of the road and aims to provide tools to quickly assess the optimal concentrations of thermal accumulation filler in the thermal protection layer. Using the unconditional optimization method on the temperature conductivity coefficient of the binary mixture, simple engineering formulas were obtained to find the optimal concentration of the thermal accumulation filler. It was established that regardless of the thickness of the thermal protection layer, the optimal concentration of the filler is a constant. However, there are values outside of the optimal range beyond which the increase of filler concentration is ineffective. It was discovered that even a minimum concentration of the filler (10%) improves the thermal stability indicator twice, and at the optimal concentration of 44% there is a threefold increase in thermal stability. The formulas and their results are visually presented in the form of charts, allowing to grasp the range in optimum concentrations of thermal accumulation fillers to achieve the highest thermal stability effects.