Results of interlaboratory tests on a laboratory bituminous mixtures ageing protocol
Résumé
RILEM TC-ATB- working group TG5, who is in charge of recycling of bituminous materials has decided to develop a laboratory procedure with the aim of reproducing the ageing of bituminous materials until the end of their service life (milled product). This procedure is meant to assess the recyclability of mixtures through production of Recycled Asphalt Pavement (RAP) in the laboratory in a realistic way. With the chosen aging protocol (divided into short and long-term ageing), the results of interlaboratory tests are presented. A bituminous material with a 35/50 penetration pure bitumen, taken from an LCPC fatigue carrousel experiment is submitted to the ageing protocol. The recovered bitumen is analysed by means of classical empirical tests (penetration and ring and ball), rheological tests (complex modulus) as well as a physico-chemical test (infra red spectroscopy) to asses the binder evolution throughout ageing. The results coming from the round robin test show that the ageing of the plant mix is similar to the ageing of the mix manufactured in the laboratory and subjected to the short-term ageing protocol, for all the indicators tested (penetration, ring and ball, DSR and FTIR). The mix subjected to long-term ageing evolves until the 9 days of the protocol and seems to lead to a considerable more aged binder compared to the classical ageing tests on binders.