Modification of cement-bound mixtures with sodium formate additives for the construction of pavement bases at low air temperatures

Abstract

Abstract The paper considers the influence of an antifrosty additive of sodium formate (SF) on the kinetics of hardening of cement-bound mixes (CBM) in the bases of road pavements at air temperatures from 00C to (-15) 0C with a cement content of 7.0% and 10.0%. The authors establish that the highest intensity of CBM hardening was noted in the first 7 days of hardening, at which the strength was 50-60% of the strength of the material at the age of 28 days. The SF modifier provides an increase in compressive strength (Rcs) of the material depending on the amount of additive and air temperature. The study makes it possible to establish the optimal consumption of SF for different temperature regimes of hardening of mixtures and at the indicated cement contents. The use of SF provides a 30% set of strength at a temperature not lower than (-5) °C. Modification of CBM with additives of SF provides the opportunity to increase the volume of construction of pavement foundations by performing work during periods of the year with lower air temperatures.