Specific Features of Heatand Mass Transfer Processes in Road Dressings

Abstract

The paper presents a fragment of on-going investigations directed on creation of optimum data environment that ensures an access to world scientific journals and other publications which are necessary for qualitative implementation of works on priority directions of R&D in the field of road-construction industry in the period of 2016–2020. A citation analysis has been applied while using data of Journal Citation Reports for selection of world scientific serial publiccations which are necessary for execution of investigations on heat and mass transfer in road dressings. The road dressings are considered as open heterogeneous thermodynamic systems. Their deformations occur under various climatic conditions due to heat and mass transfer processes and interaction of transport flows and road surface. Crack formation takes place in depth of the road dressings and on road surfaces as a result of temperature, mass transfer processes. As it is known material structure of constructive layers especially which are created with the help of technogenic wastes (asphalt-concrete, concrete, reinforced concrete scrap and products of its recycling, brick rubble, various wastes of production etc.) influence on heat and mass transfer. The paper presents results of investigations on heat flows, boundary layers according to air viscosity, velocity of geometric permeability characteristics, capillary pressures in road pavements.

Thermodynamic Aspects of Pavement Engineering

“…States of relatively stable equilibrium (metastable) are those states when the road surfaces keep in for a long time, and low external influences that cause changes in the thermophysical parameters of the road do not lead to a transition to other states. In other cases, the road platform should be considered in a metastable state persisting intermediate, relatively stable and labile [13].…”

“…For example, water is in a liquid state in temperatures of 0-100 °С and under atmospheric pressure, it turns into ice at 0 °С and under atmospheric pressure, and it turns into a vapor state at a temperature above 100 °С. When the pressure changes, the temperature changes at the points of phase transitions: from the liquid phase to the gaseous and vapor phases, here the heat is spent on expansion work and overcoming the intermolecular interaction forces and destroys the associated complexes with a decrease in the substance density [13].…”

“…The isobaric-isothermal potential decreases in a metastable region reaching a maximum in an equilibrium state and the only type of pavement work in the process of interaction with the ambient environment is expansion. The internal energy, entropy, free energy, isobaric-isothermal potential characterizing the conditions of thermodynamic road equilibrium with the ambient environment are the main equilibrium functions with the characteristic property [4,13,14]:…”

Heat Resistance and Heat-and-Mass Transfer in Road Pavements

“…Automotive highways at various climatic conditions are considered as open non-linear heterogeneous thermodynamic systems because cracking, road deformation must be studied while using synergetics principles as result of collective behavior, self-organization of structural pavement elements in case of reaching critical temperatures. Formations occurring due to these processes represent in themselves dissipative structures adapted to external conditions and in this case road dressings change their mass [1][2][3][4][5][6] as a result of heat and mass transfer with air, external flows, sources.…”

“…Density of heat flows in road pavements, their degradation are characterized by geometric roadbed dimensions (width), radiation characteristics (emissivity factor, albedo), etc. Deformation characteristics, longevity, crack resistance of road pavements depend on decay in external air temperature variations [6][7][8][9].…”