5 research outputs found

    Fatigue and healing performance of bituminous binders and mixtures for road pavement: Results of re-road project

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    An asphalt mixture is believed to be a partial self-healing material. For asphalt pavement design, this characteristic is taken into account as a shift healing factor. Healing during rest periods will result in a longer structural design life for the mixture in situ, compared to the fatigue life determined with a continuous sinusoidal test in the laboratory. For the FP7 Re-Road project, an extensive research programme was completed in order to increase the recyclability of asphalt mixtures, in particular asphalt mixtures with polymer modified binder. One research task dealt about performance modelling of asphalt pavement containing Reclaimed Asphalt (RA). For this, fatigue and healing tests were performed on virgin and aged binders, mastics and asphalt mixtures. Bituminous binders and mastics (virgin and aged) were tested using a Dynamic Shear Rheometer (DSR) in oscillation model. The fatigue and healing properties of the asphalt mixtures were determined by means of a dynamic test on compacted asphalt samples. The binders, mastic and asphalt test results show a significant increment in fatigue life when rest periods are taken into account between fatigue cycles

    Effects of reclaimed asphalt and warm mix asphalt on the availability of the road network

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    This repot reviews the EARN project, which was undertaken under CEDR Call2012 in order to investigate the effects of using reclaimed asphalt (RA) and/or lower temperature asphalt on the road network. The work consisted of a review of existing data on service lifetime and availability of road materials and structures, a site trial to evaluate varying proportions of RA, experimental evaluation of moisture damage and ageing in asphalt mixtures and development of an impact assessment model. The site trial involved four different mixtures containing varying proportions of RA and warm mix additive and was monitored for international roughness index, mean profile depth, corrected SCRIM Coefficient, indirect stiffness modulus, water sensitivity and indirect tensile strength, the latter with and without artificial ageing. The monitoring was extended to 40 months with two extensions to the project, when monitoring of the binder mechanical and other properties were also made.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Pavement Engineerin

    Effect of using of reclaimed asphalt and/or lower temperature asphalt on the availability of the road network

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    There is a need for a method for assessing the results from changes in the potential durability of road materials due to the inclusion of reclaimed and secondary component materials in the manufacture of new road materials. Such changes will have an effect on the cost of the construction maintenance, both financially to the client and environmentally to society in general, and any savings may be transitory. A site trial has been laid of mixtures with and without reclaimed asphalt and work started to assess their durability from early-life properties. The trials are being monitored for their initial performance whilstlaboratory trials are concentrating on the combined effect of ageing and moisture damage on the performance of asphalt mixtures on the trial. All three strands are being used to develop life-cycle analysis models to customise them for the effect of using alternative component materials on the availability of the network and their overall financial and environmental cost, both initial and whole-life. The costs will be identified as being direct (of the construction and maintenance) and indirect (on society in general, such as congestion).Structural EngineeringCivil Engineering and Geoscience

    Effect of using of reclaimed asphalt and/or lower temperature asphalt on the availability of the road network

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    The use of reclaimed asphalt, secondary component materials and/or additives and lower temperature asphalt are being increasingly used in order to improve the sustainability of asphalt production. The use of reclaimed asphalt reduces the need for virgin materials whilst lower temperature asphalts have reduced CO2 emissions, increased sustainability, improved working conditions for construction and maintenance crews, reduced noise level on the work sites, extended paving season and provided financial benefits from lower production and transport costs. However, there is uncertainty about the ageing and durability performance of these technologies because there is limited information available on their long-term performance. Changes in durability will affect the availability of the road network for highway authorities. CEDR commissioned a European project to assess these uncertainties. A site trial was commissioned on one of the Irelands busiest motorways (M3), comprising stone mastic asphalt mixtures containing varying proportions of the reclaimed asphalt with some using warm mix technology. The site has been monitored regularly over a full calendar year for the material performance. A suite of laboratory tests have been undertaken concentrating on the combined effect of ageing and moisture damage on the performance of asphalt mixtures on the site trial. The findings have been used to develop life-cycle analysis models to customise them for the effect of using alternative component materials on the availability of the network and their overall financial and environmental cost, both initial and whole-life. The costs identified are both direct (of the construction and maintenance) and indirect (on society in general, such as congestion). The paper describes the model and the assurance that can be given to the assumptions made within the model from the research findings. Comparative sensibility studies are included.Structural EngineeringCivil Engineering and Geoscience

    Sparsentan in patients with IgA nephropathy: a prespecified interim analysis from a randomised, double-blind, active-controlled clinical trial

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    Background: Sparsentan is a novel, non-immunosuppressive, single-molecule, dual endothelin and angiotensin receptor antagonist being examined in an ongoing phase 3 trial in adults with IgA nephropathy. We report the prespecified interim analysis of the primary proteinuria efficacy endpoint, and safety. Methods: PROTECT is an international, randomised, double-blind, active-controlled study, being conducted in 134 clinical practice sites in 18 countries. The study examines sparsentan versus irbesartan in adults (aged ≥18 years) with biopsy-proven IgA nephropathy and proteinuria of 1·0 g/day or higher despite maximised renin-angiotensin system inhibitor treatment for at least 12 weeks. Participants were randomly assigned in a 1:1 ratio to receive sparsentan 400 mg once daily or irbesartan 300 mg once daily, stratified by estimated glomerular filtration rate at screening (30 to 1·75 g/day). The primary efficacy endpoint was change from baseline to week 36 in urine protein-creatinine ratio based on a 24-h urine sample, assessed using mixed model repeated measures. Treatment-emergent adverse events (TEAEs) were safety endpoints. All endpoints were examined in all participants who received at least one dose of randomised treatment. The study is ongoing and is registered with ClinicalTrials.gov, NCT03762850. Findings: Between Dec 20, 2018, and May 26, 2021, 404 participants were randomly assigned to sparsentan (n=202) or irbesartan (n=202) and received treatment. At week 36, the geometric least squares mean percent change from baseline in urine protein-creatinine ratio was statistically significantly greater in the sparsentan group (-49·8%) than the irbesartan group (-15·1%), resulting in a between-group relative reduction of 41% (least squares mean ratio=0·59; 95% CI 0·51-0·69; p<0·0001). TEAEs with sparsentan were similar to irbesartan. There were no cases of severe oedema, heart failure, hepatotoxicity, or oedema-related discontinuations. Bodyweight changes from baseline were not different between the sparsentan and irbesartan groups. Interpretation: Once-daily treatment with sparsentan produced meaningful reduction in proteinuria compared with irbesartan in adults with IgA nephropathy. Safety of sparsentan was similar to irbesartan. Future analyses after completion of the 2-year double-blind period will show whether these beneficial effects translate into a long-term nephroprotective potential of sparsentan. Funding: Travere Therapeutics
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