Dependence of penetration of highway bitumens on temperature

1. A simple formula is proposed making it possible to determine the value of penetration of highway bitumens in a temperature interval of from plus 30 to minus 30 °C and giving good agreement with experimental results. 2. The determination of penetration of highway bitumens at various temperatures should be carried out with an identical charge of 100 g and a time of 5 sec for research purposes.