Laboratory investigation of bitumen based on round robin DSC and AFM tests

In the past years a wide discussion has been held among asphalt researchers regarding the existence and interpretation of observed microstructures on bitumen surfaces. To investigate this, the RILEM technical committee on nano bituminous materials 231-NBM has conducted a round robin study combining differential scanning calorimetry (DSC) and Atomic Force Microscopy (AFM). From this, methods for performing DSC and AFM tests on bitumen samples and determination of the influence of wax on the observed phases, taking into account thermal history, sample preparation and annealing procedure, are presented and critically discussed. DSC is used to measure various properties and phenomena that indicate physical changes such as glass transition temperature (T g) and phase transition such as melting and crystallization. In the case of existence of wax, either natural or synthetic, it can further indicate the melting point of wax, that could be used to determine wax content. The results from seven laboratories show that T g temperatures obtained from the heating scans are more repeatable and easier to obtain in comparison to the cooling scans. No significant difference was noted for T g's obtained from the first and second heating scans. AFM is an imaging tool used to characterize the microstructures on a bituminous surface. Using AFM three phases in the materials with wax could be distinguished. The changes in the phases observed with AFM for increases in temperature were correlated with the DSC curve, and it could be established that the so called "Bee” structure disappeared around the melting peak in the DSC curve. Thus, this research has confirmed the relation between the microstructures on a bitumen surface and the wax content

BioRePavation - Innovation In Bio-Recycling

The main scientific and technical objectives of the BioRePavation project have been to prove that alternative binders can be used to recycle asphaltic pavement with the same level of performance as conventional solutions with petroleum bitumen. To do so, the consortium proposed to build a demonstration where three innovative pavement solutions using bio-materials were tested using an accelerated pavement testing facility (IFSTTAR fatigue carousel): - A bio-based additive from pine chemistry designed to Increase RA content to 70%, even 100% in theory - A Bio-based additive designed to increase compatibility between fresh bitumen and RA: Epoxidized Methyl Soyate - A Biobitumen designed for full replacement of fresh bitumen The survey of performance was performed by both measuring the traffic level needed for the pavement solution to reach a distress mechanism and investigating the binder physicochemical evolution using an innovative non-destructive method. BioRePavation also assessed the environmental impacts of the combined use of bio-binders and high-content of RA in asphalt mixes. Special attention was given to airborne emissions that were directly measured in the laboratory. Obtained data were used to perform a risk assessment, as well as a Life Cycle Assessment (LCA) for the aforementioned BioRePavation technologies. Finally, the proof of concept was demonstrated: the innovative pavement mixes assessed in the BioRePavation international project behave better than a conventional reference mix. They now provide durable solutions, assessed by a full scale accelerated test and an environmental analysis, to build roads using high rate recycling and involving biomaterials as additive or alternative to bitumen.This proceeding is published as Pouget, S.; Chailleux, E.; Porot, L.; Williams, R.C.; Planche, J.P.; Lo Presti, D.; Blanc, J.; Hornych, P.; Del Barco Carrion, A.J.; and Gaudefroy, V. “BioRePavation - Innovation In Bio-Recycling”, 7th Eurasphalt & Eurobitume Congress- Asphalt 4.0 for future mobility, Madrid, Spain (Virtual), June 2021. Copyright 2021, European Asphalt Pavement Association and the European Bitumen Association. Posted with permission

From Laboratory Mixes to Full Scale Test: Rutting Evaluation of Bio-recycled Asphalt Mixes

The present paper describes the rutting behavior of innovative mixes in-corporating 50% of Reclaimed Asphalt (RA) with bio-materials. They were assessed in the laboratory and in a full-scale accelerated experiment. The innovative mixes studied here contain bio-materials especially designed to help recycling by re-activating the aged binder in RA. Four mixes were evaluated: three of them are manufactured with bio-materials, (two bio-rejuvenators and one bio-binder) and one is a control mix, which is a high modulus asphalt mix (EME2). In this study, the rutting resistance of the four mixes was first evaluated in the laboratory with both European and US methods. The full-scale test was then performed in order to evaluate the rutting resistance of the bio-recycled asphalt mixes under heavy traffic (200 000 load cycles loaded at 65 kN) and compare it with the control. A simplified analysis leads to the conclusion that, with the Nantes climate, a daily traffic of 150 heavy vehicles per day applied for 20 years corresponds to approximately 200 000 heavy vehicle loads applied when the surface temperature exceeds 30°C. Therefore, it can be considered that the rutting evaluation made on the carrousel represents almost 20 years of traffic during hot periods. The results obtained on the test track are consistent with the laboratory rutting tests showing good performance of all the mixes. The materials presenting the best performance on the test track also presented the best performance in the laboratory.This is a manuscript of a proceeding published as Juliette Blanc, Emmanuel Chailleux, Pierre Hornych, Chris Williams, Zahra Sotoodeh-Nia, et al. (2022). From laboratory mixes to full scale test: rutting evaluation of bio-recycled asphalt mixes. RILEM International Symposium on Bituminous Materials. ISBM 2020, Dec 2020, Lyon, France. pp.951-957, 10.1007/978-3-030-46455-4_121. hal-04376794. Manuscript is distributed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. © The Author(s), under exclusive license to Springer Nature Switzerland AG 202

Acceptability and efficacy of intra-rectal quinine alkaloids as a pre-transfer treatment of non-per os malaria in peripheral health care facilities in Mopti, Mali

<p>Abstract</p> <p>Background</p> <p>The acceptability and efficacy of a new kit with a new formulation of quinine alkaloids designed for the intra-rectal administration in the treatment of non-per os malaria was assessed in the peripheral health care system of Mopti, Mali.</p> <p>Methods</p> <p>A single-arm trial was conducted from August 2003 to January 2004. An initial dose of diluted quinine alkaloids (20 mg/kg Quinimax^®) was administered by the intra-rectal route to children with presumptive non per-os malaria at six peripheral heath care centres. The children were then referred to two referral hospitals where standard inpatient care including intravenous route were routinely provided. A malaria thick smear was done at inclusion and a second malaria thick smear after arrival at the referral facility, where a more complete clinical examination and laboratory testing was done to confirm diagnosis. Confirmed cases of severe malaria or others diseases were treated according to national treatment guidelines. Cases of non per-os malaria received a second dose of intra rectal quinine alkaloids. Primary outcome was acceptability of the intra rectal route by children and their parents as well as the ease to handle the kit by health care workers.</p> <p>Results</p> <p>The study included 134 children with a median age of 33 months and 53.7% were male. Most of the children (67%) and 92% of parents or guardians readily accepted the intra-rectal route; 84% of health care workers found the kit easy to use. At the peripheral health care centres, 32% of children had a coma score ≤ 3 and this was reduced to 10% at the referral hospital, following one dose of intra-rectal quinine alkaloids (IRQA). The mean time to availability of oral route treatment was 1.8 ± 1.1 days. Overall, 73% of cases were confirmed severe malaria and for those the case fatality rate was 7.2%.</p> <p>Conclusion</p> <p>IRQA was well accepted by children, their parents/guardians and by the health workers at peripheral health facilities in Mopti, Mali. There was also a quick recovery from deep coma and a reduced case fatality rate in severe malaria.</p

Evolution à long terme des performances d’un bitume modifié SBS

Pour répondre à l’incertitude sur les performances des nouveaux liants modifiés aux polymères, des sections expérimentales ont été mises en place en 1988 sur une autoroute suisse. Après 19 ans de service, un bilan de l’expérience a été mené qui montre que l’un des produits ne présente toujours pas de dégradation. Les analyses en laboratoire relèvent la bonne résistance au vieillissement de l’enrobé au liant Styrelf® 13/80. Les valeurs de modules et de résistance à la fatigue sont également remarquables

A Tale of Two Deltas: Analysis approach, proposed limits, and validation work to address binder quality-related thermally induced surface damage

Superpave specifications address binder properties that may lead to rutting, transverse cracking, and fatigue damage with varying degrees of success. However, asphalt binder production and formulation has significantly changed and introduced much more variability in terms of quality since the development of Superpave Performance-Grade system because of economic, technical, and environmental reasons. Consequently, aged-induced surface distresses under combined thermal and traffic loading have become the main challenge for highway agencies. Thermally induced surface deterioration appears in the form of traditional transverse cracking, block cracking, and raveling, or accelerating damage at construction joints. This study evaluated the limitations of the proposed linear viscoelastic (LVE) rheological cracking surrogates, such as ΔTc, R-value, and G-R parameters, and the ability of the Asphalt Binder Cracking Device (ABCD) failure test to overcome these limitations. ABCD is particularly appropriate to rank binder performance because the measured cracking temperature (Tcr) encompasses binder LVE properties, failure strength, coefficient of thermal contraction, and cooling rate. The proposed parameter (ΔTf = Tc (S=300 MPa) from BBR - Tcr from ABCD) relates the failure temperature to the equi-stiffness temperature and gives credit to well-formulated and compatible polymer-modified binders expected to increase binder strength and strain tolerance. This paper proposes a specification framework based on both ΔTc and ΔTf, universally applicable, regardless of binder composition. Additionally, preliminary specification limits are proposed based on the analysis of 44 binders, 15 with corresponding field performance data. Obviously as confirmed by a recent stakeholder workshop and industry feedbacks, these preliminary specification limits need further validation and possible adjustments to account for regional experience and local challenges. Current efforts at FHWA TFHRC, in collaboration with various State Highway Agencies (SHA’s), are focused to further validate the framework and specification limits

Bio materials with reclaimed asphalt: from lab mixes properties to non-damaged full scale monitoring and mechanical simulation

Three innovative environmentally friendly pavement materials, designed with 50% of Reclaimed Asphalt and three different biomaterials (2 bio-additivated bitumens and 1 bio-binder), were produced in an industrial plant. These mixes were tested in lab and also at full scale using an Accelerated Pavement Test facility. The asphalt mix viscoelastic properties were measured in lab and their intrinsic viscoelastic response were simulated. These rheological models are used to simulate the pavement mechanical response using both elastic and viscoelastic multilayer codes. Hence, full scale measurement performed during the full scale test at an early stage (without damages) can be compared with these simulations. The overall prediction accuracy, when all the signals are considered, is between 4% and 8% for all materials. It can be concluded that material characterisation in lab as well as the selected models are well adapted to simulate actual loading state under a moving load, even for these non-conventional mixes. For temperatures lower than 25°C, elastic modelling appears to be sufficient for pavement structural design with the innovative materials tested here

Racine : Théâtre et émotion

Ce numéro 42 de Coulisses contient un dossier d’articles sur Racine, portant notamment sur la dramaturgie racinienne, l’accueil critique de La Thébaïde aux XVIIIe et XIXe siècles, mais également sur Andromaque, Athalie et Mithridate. Une belle analyse de l’iconographie des illustrations illustrées La Thébaïde, Britannicus et Mithridate, ainsi qu’une interview du metteur en scène Gwenaël Morin viennent compléter cette réflexion sur « Racine : théâtre et émotion ». La section Varia propose un article de théâtre/danse sur le spectacle créé par Hélène Harmat à Hambourg en 2010, Oh pardon j’étais dans d’autres sphères. Il est suivi de comptes rendus de spectacles : Roméo et Juliette de Guillaume Dujardin par David Ball, Les Indes dansantes de Nathalie Pernette et Hervé Niquet par Karine Bénac. Un hommage à Philippe Baron par Lucile Garbagnati précède le premier inédit d’une série consacrée aux dramaturges antillais : Pater familias de Gaël Octavia

Bio materials with reclaimed asphalt: from lab mixes properties to non-damaged full scale monitoring and mechanical simulation

Three innovative environmentally friendly pavement materials, designed with 50% of Reclaimed Asphalt and three different biomaterials (2 bio-additivated bitumens and 1 bio-binder), were produced in an industrial plant. These mixes were tested in lab and also at full scale using an Accelerated Pavement Test facility. The asphalt mix viscoelastic properties were measured in lab and their intrinsic viscoelastic response were simulated. These rheological models are used to simulate the pavement mechanical response using both elastic and viscoelastic multilayer codes. Hence, full scale measurement performed during the full scale test at an early stage (without damages) can be compared with these simulations. The overall prediction accuracy, when all the signals are considered, is between 4% and 8% for all materials. It can be concluded that material characterisation in lab as well as the selected models are well adapted to simulate actual loading state under a moving load, even for these non-conventional mixes. For temperatures lower than 25°C, elastic modelling appears to be sufficient for pavement structural design with the innovative materials tested her