This article discusses the results of bitumen foam properties optimisation with respect to three factors: air pressure, bitumen temperature and amount of water. The test materials were unmodified bitumen 50/70 and bitumen 50/70 modified with 2.5% synthetic wax. The experiment was designed according to the 3(3−1) fractional factorial design. The distribution of parameters of bitumen foam were measured with the authors’ original apparatus using a laser beam. This measurement method increased the accuracy of maximum expansion ratio (ER) and half-life (HL) estimation. Based on HL and ER results, it was found that the foaming process increased bitumen stiffness due to the dynamic ageing of the bitumen. The experimental design allows more effective control over the properties of foamed bitumen with respect to its intended use. The presence of synthetic wax extended the half-life of the bitumen foam.

No abstract

No abstract

No abstract

Przeanalizowano wp³yw ró¿nej zawartooeci (0,5-4,0 % mas.) wosku syntetycznego Fischera-Tropscha (F-T) w mieszance z asfaltem 35/50 na: penetracjê (P), temperaturê ³amliwooeci Fraassa (T Fraass ), temperaturê miêknienia (T PiK ), lepkooeae dynamiczn¹ (h) w temp. 60-145 °C, modu³ zespolony (G*), lepkooeae zerowego oecinania (ZSV), k¹t przesuniêcia fazowego (d) oraz charakterystykê MSCR lepiszcza przeznaczonego do wytworzenia mieszanki mineralno-asfaltowej metod¹ "na ciep³o" (WMA). Wykazano, ¿e badany modyfikator, ju¿ w ilooeci 1 % mas., korzystnie wp³ywa na oceniane w³aoeciwooeci funkcjonalne asfaltu, zw³aszcza na jego charakterystykê reologiczn¹.