MURE National Project: FTIR spectroscopy study to assess ageing of asphalt mixtures

Abstract

The French national project MURE, a collaborative research and development programme, started in March 2014. Two main issues are addressed: coupling of recycling and warm-mix asphalt technique and multi-recycling of bituminous mixtures. It gathers the national road federation, academic laboratories, road contractors and project contracting officials. The objective of the first working group (WG1) of MURE is to validate an accelerated ageing process for bituminous mixtures as well as on site than in laboratory. To achieve this goal, it is first necessary to characterize the ageing using a reliable and reproducible method valid for laboratory and plant-made mixtures. Many studies from the literature showed the efficiency of FTIR spectroscopy for ageing identification. In particular, carbonyl and sulfoxide groups found in binders are appropriate ageing markers. Meanwhile, no common FTIR protocol does exist at present. The first step of the experimental work performed by the WG1 was to compare seven FTIR methods, differing from sample preparation and approaches for calculating spectroscopic indexes. One given bitumen was aged eight times successively by RTFOT method (75 min-163 °C). Two IR spectrum acquisition modes were tested: attenuated total reflectance (ATR) and transmission (spreading of bitumen on an IR transparent plate and bitumen dissolution in a solvent). The second step of the study was to verify the repeatability of FTIR tests on neat and aged bitumen according to sample preparation and calculation methods. The results allow confirming the relevance of FTIR spectroscopy for qualifying bitumen ageing. A single methodology and a common tool for harmonizing the calculation of indexes are proposed. The whole procedure can be used to follow the ageing properties on site at short and long times.

Experimental investigation of the oxidative ageing mechanisms in bitumen

“…Possible chemical changes could induce stronger interactions and change the bitumen microstructure which may have implications in the mechanical behaviour. Given this, there is a growing body of evidence that an increase in apparent molecular weight due to increased molecular interactions can reduce the mobility of molecules to flow which, in turn, will influence the bitumen rheology [17][18][19][20]. Eventually, there is a widespread recognition that the severity of ageing can be tracked by capturing the change in certain functional groups [13,18,19,21,22].…”

Investigation Prosperities Of Brick Mixes with Chemically Depolymerized Waste polyethylene terephthalate Aggregates

“…At a high of 727 cm-1, the meta-aromatic functional groups are discernible. Assuming there was a hydrogen bond there, the ether peak displayed a decline from 1066 to 1019 [30]. Increasing bitumen polarity, bitumen aromaticity, and bitumen molecule size, as well as hardening brittle bituminous binder [29].…”

Physicochemical and Rheological Properties of A Transparent Asphalt Binder Modified with Nano-TiO2

“…Chemical characterization of binders has received attention in the literature as it can present functional groups related to the crude oil origin, the polymer modification, and the degree of oxidation [30][31][32][33][34][35]. Since this paper aims to analyze the chemical characteristics of the transparent binder modified with nano-TiO2, three approaches were carried out: i) identification of FTIR peaks; ii) establishment of a possible relationship between the TiO2 modification level and related chemical groups; and iii) comparison of standard indices with reference binders used in this study.…”