Optimization of complex frost-resisting additives in line with operational requirements towards freezing temperature in road dressing constructions

Abstract

The subject of the study is to optimize the compositions containing frost-resisting complex organic and inorganic additives (FRA) that provide the required level towards freezing temperature when constructing cement-mineral layers (CML) of road dressing (pavement). As a prerequisite to carry out these studies is the necessity to preserve the liquid phase in CML during asphalt laying at low (subzero) air temperatures, as well as ensuring a given level stated to the performance criteria and durability of road dressing layers. In our studies, we applied the comprehensive approach to the experiment, concluding in a choice of FRA components and in the use of experiment planning. The influence of functional additives and their quantitative composition on the freezing temperature (Tz ) during the experiment optimization in line with the D-optimal second-order plan has been considered. A mathematical model of the process has been obtained. We have found that the most significant mixture is the content of sodium formate (SF), compared to calcium chloride (CaCl2) and a superplasticizer based on the polycondensation product of naphthaleisulfonic acid and formaldehyde (C-3), the amount of which varies in the series 3>1>0.3. The obtained results on optimization allow to choose FRA compositions that provide the ability to perform construction works in conditions of subzero temperatures up to -15.6 C.