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Visar resultat 1 - 5 av 28 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Gradation-Based Framework for Asphalt Mixtures

   Författare :Bernardita Francisca Lira Miranda; Björn Birgisson; Terhi Pellinen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Asphalt; aggregate gradation; packing theory; asphalt microstructure; porosity; film thickness; rutting; moisture damage.; SRA - Transport; SRA - Transport;

   Sammanfattning : Asphalt mixture microstructure is formed by aggregates, bitumen binder and air voids. Aggregates make for up to 90% of the mixtures volume and the structure formed by them will depend mostly on their size distribution and shape. LÄS MER

3. 2. Ageing of Asphalt Mixtures : Micro-scale and mixture morphology investigation

   Författare :Prabir Kumar Das; Björn Birgisson; Nicole Kringos; Andreas Loizos; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ageing; Aggregate packing; Atomic force microscopy; Asphalt mixture; Bitumen; Diffusion; Finite element analysis; Gradation; Micro-structure; Mixture morphology; Oxidative ageing; Surface ageing;

   Sammanfattning : There are many variables that affect the viscoelastic properties of asphalt mixtures with time, among which age hardening may be considered one of the important ones. Age hardening of asphalt mixtures is an irreversible process, which contributes to a reduction of the durability of pavements and eventually increases the maintenance cost. LÄS MER

4. 3. Influence of waxes on bitumen and asphalt concrete mixture performance

   Författare :Ylva Edwards; Ulf Isacsson; Klaus-Werner Damm; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bitumen; asphalt; additives; wax in bitumen; polyphosphoric acid in bitumen; rheology; IR-spectroscopy; dynamic mechanic analysis DMA ; bending beam rheometer BBR ; literature study; low temperature physical hardening; highway materials; morphology; modified bitumens; temperature susceptibility; low temperature performance; ageing; microscopy; chromatography; Fourier transform infrared spectroscopy; force ductility; conventional binder tests; asphalt performance; tensile strain restrained specimen test TSRST ; Building engineering; Byggnadsteknik;

   Sammanfattning : This doctoral thesis consists of a literature review, presented in two papers, and another six papers describing experimental studies of the influence of different kinds of wax and polyphosporic acid on bitumen and asphalt concrete mixture properties. The literature review should give an extensive description of the field of knowledge concerning wax in bitumen. LÄS MER

5. 4. On Rheological Testing and Modelling of Asphalt Mixtures with Emphasis on Fatigue Characterisation

   Författare :Robert Lundström; KTH; []
   Nyckelord :Rheology; Fatigue; Asphalt mixtures; Damage Mechanics; Viscoelasticity;

   Sammanfattning : .... LÄS MER

7. 5. Thermally Induced Fracture Performance of Asphalt Mixtures

   Författare :Prabir Kumar Das; Björn Birgisson; Dallas Little; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low temperature cracking; asphalt concrete fracture mechanics; viscoelasticity; non-linear thermal contraction coefficient; atomic force microscopy; wax; wax crystallization; SRA - Transport; SRA - Transport;

   Sammanfattning : A major distress mode in asphalt pavements is low temperature cracking, which results from the contraction and expansion of the asphalt pavement under extreme temperature changes. The potential for low temperature cracking is an interplay between the environment, the road structure and importantly the properties of the asphalt mixture. LÄS MER