Stiffness of asphalt mixtures with addition of recycled asphalt material

Abstract

Reclaimed Asphalt Pavement (RAP) is largely used in developed countries in the hot-asphalt mixtures. One of the most important characteristics of asphalt mixtures is their stiffness which depends on temperature and loading frequency. Master curves define the change of stiffness with frequency for the specified temperature and they are used for comparison of asphalt mixtures and for pavement design. The paper presents the testing of three asphalt mixtures: a mixture without RAP and with 15% and 30% of RAP. The indirect tensile test was performed at temperatures of 0 °C to 30 °C and the load duration was 200 and 300 ms to obtain stiffness moduli. The results indicate that the addition of 30% RAP significantly increases the stiffness of the mixture, while the addition of 15% RAP results in relatively small increase of stiffness, which means that the use of up to 15% RAP has no significant effect on the characteristics of the mixture. .

Strugani asfaltni materijal (RAP - Reclaimed Asphalt Pavement) se u razvijenim zemljama u značajnoj meri koristi pri proizvodnji asfaltnih mešavina po vrućem postupku.Jedna od najznačajnijih karakteristika asfaltnih mešavina je njihova krutost, koja zavisi od temperature i frekvencije opterećenja. Master krive definišu promenu modula krutosti sa frekvencijom opterećenja na određenoj temperaturi i koriste se za upoređenje asfaltnih mešavina i za dimenzionisanje kolovoznih konstrukcija. U okviru rada su ispitane tri mešavine: mešavina bez struganog materijala, sa 15% i sa 30% struganog materijala. Ispitivanje je vršeno pri temperaturama od 0 oC do 30 oC i pri trajanju opterećenja od 200 i 300 ms korišćenjem opita indirektnog zatezanja. Dobijeni rezultati ukazuju da dodatak struganog materijala od 30 % u značajnoj meri povećava krutost mešavine, dok dodatak od 15 % relativno malo utiče na povećanje krutosti što znači da primena do 15 % struganog materijala nema značajnog efekta na promene karakteristika mešavine.