다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Research on Life Cycle Assessment (LCA) was initially performed to analyze specific products; however, it evolved to assess environmental impacts of more complex systems, such as roads. In this, the construction, use and maintenance stages are usually considered. The results of different studies revealed that all stages have relevant environmental impacts like topsoil loss, change in the use of land, modification of natural drainage and groundwater patterns, landslides, erosion, sedimentation, landscape degradation, increase in noise and dust levels, fuel and oil spills, waste generation, and air, soil and water pollution. This paper presents the results of a literature review on the application of LCA in road construction as a tool to quantify the potential impacts derived from the use of traditional and alternative materials. The research showed that the most common materials found were recycled asphalt (concrete and bitumen), fly ash, and polymer. In addition, the environmental impact categories more commonly assessed were energy consumption and global warming potential (GWP). These results claimed that the construction of roads should be directed towards the fulfilment of technical, social, economic and environmental criteria. Finally, it was found that most of the studies were performed for high traffic volume roads; therefore, for developing countries, research is needed focussed on low traffic ones.

Life cycle assessment of road construction alternative materials: A literature review

Mechanical performance of fibers in hot mix asphalt: a review

Review of warm mix rubberized asphalt concrete: Towards a sustainable paving technology

Life cycle assessment of pavements: reviewing research challenges and opportunities

https://repository.tudelft.nl/islandora/object/uuid%3A29b7ab5f-40ec-464b-a8f0-e24284a439f0/datastream/OBJ/download

Electrical and mechanical properties of asphalt concrete containing conductive fibers and fillers

Aging during construction and in-service substantially changes the chemical composition and physical properties of bitumen thereof influences the performance of asphalt pavements. The modification of bitumen by crumb rubber modifier (CRM) significantly increases the complexity of the aging mechanism and is expected to improve the aging resistance of bitumen. This study aims to investigate the effects of laboratory short-term and long-term aging on the chemistry and rheology of crumb rubber modified bitumen (CRMB). Neat bitumen and CRMB with four different CRM contents were studied. Fourier transform infrared spectroscopy and dynamic shear rheometer were employed to measure the change in the chemical composition and rheological properties of binders at different aging states. Bitumen hardening, which was rheologically revealed by the frequency sweep and multiple creep recovery test results, was also reflected in the growth of carbonyl and sulfoxide functional groups. In addition, the aliphaticity and aromaticity indices of binders before and after aging were also investigated. CRMB binders showed improved aging resistance compared to neat bitumen as reflected by the decreased carbonyl and sulfoxide indices as well as the lower change in rheological parameters. Higher resistance against aging was achieved when increasing the CRM content. The results also highlight the correlation between chemistry and rheology of bitumen. Among six selected mechanical parameters of binder, the non-recoverable creep compliance and percent recovery show better correlations with the combined chemical aging index (sum of carbonyl and sulfoxide indices) than the parameters derived from the linear viscoelastic region.

/pdf/effect-of-laboratory-aging-on-chemistry-and-rheology-of-2ik8kccmvo.pdf

Effect of laboratory aging on chemistry and rheology of crumb rubber modified bitumen

Warm mix asphalt (WMA) technology has been increasingly utilised in rubberised asphalt pavements to reduce the production and compaction temperatures and the incidental fumes and odours. This study...

https://tandfonline.com/doi/pdf/10.1080/14680629.2018.1561380

Asphalt-rubber interaction and performance evaluation of rubberised asphalt binders containing non-foaming warm-mix additives

The microstructure and chemical composition of asphalt binders have a significant effect on their rheological properties and, therefore, their performance as road paving binders. This study aims to investigate the effects of warm-mix asphalt (WMA) additives, organic type and chemical type, on the rheological properties and chemical internal structure of base asphalt and crumb rubber modified asphalt (CRMA). A set of dynamic shear rheometer (DSR) tests was conducted to obtain the rheological parameters (e.g., complex viscosity, complex modulus, phase angle) of asphalt binders. The flow activation energy was calculated from Arrhenius equation based on viscosity data to rank the thermal susceptibility. Black diagrams and master curves of complex modulus and phase angle were utilized to analyze the rheological properties. The molecular weight distributions of asphalt binders were inverted from the phase angle master curve to evaluate the molecular weight characteristics. It was found that the the addition of crumb rubber into base asphalt improves the rheological properties of enhanced modulus and elasticity. Organic and chemical types of WMA additives have different chemo-physical effects on both base asphalt and CRMA. Phase angle inversion method provides a powerful tool to monitor the molecular structure change and, therefore, the chemo-physical interactions of asphalt binders induced by modifications. Finally, there is a good correlation between flow activation energy and molecular weight

/pdf/rheological-behavior-and-its-chemical-interpretation-of-kgn0f6s1gi.pdf

Haopeng Wang

Papers

Review of warm mix rubberized asphalt concrete: Towards a sustainable paving technology

Electrical and mechanical properties of asphalt concrete containing conductive fibers and fillers

Effect of laboratory aging on chemistry and rheology of crumb rubber modified bitumen

Asphalt-rubber interaction and performance evaluation of rubberised asphalt binders containing non-foaming warm-mix additives

Rheological Behavior and Its Chemical Interpretation of Crumb Rubber Modified Asphalt Containing Warm-Mix Additives: