Sökning: "gradation"

Visar resultat 1 - 5 av 19 avhandlingar innehållade ordet gradation.

  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. Influence of aggregates on permanent deformation of asphalt

    Författare :Bernardita Francisca Lira Miranda; Robert Lundström; Stefan Larsson; Alan Carter; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Asphalt; deformation; rutting; gradation; flakiness index; Asfalt; kornstorleksfördelning; flisighetsindex; permanent deformation; spårbildning.; Jord- och bergmekanik; Soil and Rock Mechanics;

    Sammanfattning : One of the most common failure modes for asphalt pavements is the occurrence of permanent deformation on the wheel path. This leads to not only other distresses, such as potholes and stripping, but also decreases substantially road safety and increases maintenance costs. LÄS MER

  4. 3. Performance model for unbound grnular materials pavements

    Författare :Tatek Fekadu Yideti; Björn Birgisson; Andrew Dawson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; unbound granular materials; aggregate; packing theory; gradation; primary structure; secundary structure; permanent deformation; resilient modulus;

    Sammanfattning : Recently, there has been growing interest on the behaviour of unbound granular material in road base layers. Researchers have studied that the design of a new pavement and prediction of service life need proper characterization of unbound granular materials, which is one of the requirements for a new mechanistic design method in flexible pavement. LÄS MER

  5. 4. 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

  7. 5. Generation of urban runoff : Seasonal and climate change perspective

    Författare :Shahab Moghadas; Claes Hernebring; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VA-teknik; Urban Water Engineering;

    Sammanfattning : Runoff generation in cold regions is characterized by snowmelt contributions to runoff during the periods of thawing and changing runoff patterns due to frozen ground. This thesis project aimed at addressing these challenges by advancing the procedures for winter urban runoff computations and the assessment of control measures during the winter/spring period, when the snowmelt and frozen soils dominantly impact runoff generation in the current and future climates. LÄS MER