The Experts below are selected from a list of 12966 Experts worldwide ranked by ideXlab platform

Olivier Burban - One of the best experts on this subject based on the ideXlab platform.

  • Influence of the compaction process on the Air Void homogeneity
    Construction and Building Materials, 2010
    Co-Authors: Vincent Dubois, Chantal De La Roche, Olivier Burban
    Abstract:

    The effectiveness of laboratory compaction methods, for reproducing asphalt mixtures specimens with the same characteristics as on the actual building site, remains relatively unknown. The present paper in aimed at investigating the variability in Air Void content, therefore in compaction level, of three asphalt mixture types : a continuously-graded mix, an open-graded asphalt.

  • influence of the compaction process on the Air Void homogeneity of asphalt mixtures samples
    Construction and Building Materials, 2010
    Co-Authors: Vincent Dubois, Olivier Burban
    Abstract:

    Abstract The effectiveness of laboratory compaction methods, for reproducing asphalt mixtures specimens with the same characteristics as on the actual building site, remains relatively unknown. The present paper is aimed at investigating the variability in Air Void content, therefore in compaction level, of three asphalt mixture types: a continuously-graded mix, an open-graded sandy mix, and a gap-graded asphalt. Several types of compactors are tested and the influence of sample dimensions and compaction axis vs. the main sample axis regarding Air Void homogeneity are studied using gamma-ray measurement. This study shows that for the studied materials, the samples cored in the plate are the most homogeneous, the ones produced by gyratory compaction yield scattered results but rather homogeneous samples can be obtained by respecting geometry criteria for the samples to be produced, and by sawing the edges where the compaction is the least efficient.

Vincent Dubois - One of the best experts on this subject based on the ideXlab platform.

  • Influence of the compaction process on the Air Void homogeneity
    Construction and Building Materials, 2010
    Co-Authors: Vincent Dubois, Chantal De La Roche, Olivier Burban
    Abstract:

    The effectiveness of laboratory compaction methods, for reproducing asphalt mixtures specimens with the same characteristics as on the actual building site, remains relatively unknown. The present paper in aimed at investigating the variability in Air Void content, therefore in compaction level, of three asphalt mixture types : a continuously-graded mix, an open-graded asphalt.

  • influence of the compaction process on the Air Void homogeneity of asphalt mixtures samples
    Construction and Building Materials, 2010
    Co-Authors: Vincent Dubois, Olivier Burban
    Abstract:

    Abstract The effectiveness of laboratory compaction methods, for reproducing asphalt mixtures specimens with the same characteristics as on the actual building site, remains relatively unknown. The present paper is aimed at investigating the variability in Air Void content, therefore in compaction level, of three asphalt mixture types: a continuously-graded mix, an open-graded sandy mix, and a gap-graded asphalt. Several types of compactors are tested and the influence of sample dimensions and compaction axis vs. the main sample axis regarding Air Void homogeneity are studied using gamma-ray measurement. This study shows that for the studied materials, the samples cored in the plate are the most homogeneous, the ones produced by gyratory compaction yield scattered results but rather homogeneous samples can be obtained by respecting geometry criteria for the samples to be produced, and by sawing the edges where the compaction is the least efficient.

Alvaro Garcia - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Air Void structures on the coefficient of permeability of asphalt mixtures
    Powder Technology, 2020
    Co-Authors: Siyu Chen, Alvaro Garcia, Zhanping You, Song-lin Yang, Luke Rose
    Abstract:

    Abstract The objectives of this study are (i) to investigate the Air Void properties and (ii) predict the three-dimensional coefficient of permeability of asphalt mixtures by means of the Lattice Boltzmann Method (LBM). Asphalt mixtures with five different gradations and Air Voids content ranging from 13.7% to 26% were used in this study. The three-dimensional structures of Air Voids in asphalt mixtures were examined by various parameters and used as inputs for LBM simulations. It was found that the Air Voids content, Euler number, average Void diameter, tortuosity, and degree of anisotropy were highly correlated to the coefficients of permeability. In addition, the permeability values predicted by LBM had a significant correlation to the laboratory measurements for all the range of mixtures studied. It was concluded that the Air Void structures in the horizontal directions were equivalent and, in addition, they differed from those in the vertical direction.

  • Study the influence of the Air Void topology on porous asphalt clogging
    Construction and Building Materials, 2019
    Co-Authors: Alvaro Garcia, M. Aboufoul, F. Asamoah, D. Jing
    Abstract:

    Abstract This paper investigates the effect of Air Void topology on the clogging properties of asphalt mixtures with porosity in the range 13.6%–31.8%. The Air Void properties of the asphalt mixtures were quantified by means of computed tomography of the asphalt. In addition, virtual pore networks were generated using the Intersected Stacked Air Voids (ISA) method and then, 3D printed using transparent resin. The porous asphalt and the transparent resin with realistic pores were clogged by letting water and dust pass through the pores during hydraulic conductivity tests. The clogging ratio was measured by quantifying the reduction in hydraulic conductivity after each clogging cycle. The volume of pores clogged was quantified by means of thresholded images of the transparent resin with realistic pores. Furthermore, the clogging ratio of each test specimen was compared against its Air Void topologies, such as average pore diameter, tortuosity, Euler number, and macroporosity. It was found that the main factor influencing the clogging ratio of asphalt mixture was the Air Void diameter and the reason for this, is because particles of similar size to the pores have a high chance to block them. Tortuosity, Euler number, and macroporosity, do not have a significant influence on the clogging ratio of asphalt mixture. Finally, it was concluded that to build mixtures that do not clog, the size distribution of the clogging particles must be analysed prior to building the road and the maximum aggregate size and gradation carefully selected to produce pores which are bigger than the clogging particles.

  • virtual porous materials to predict the Air Void topology and hydraulic conductivity of asphalt roads
    Powder Technology, 2019
    Co-Authors: M. Aboufoul, Andrea Chiarelli, I Triguero, Alvaro Garcia
    Abstract:

    Abstract This paper investigates the effects of Air Void topology on hydraulic conductivity in asphalt mixtures with porosity in the range 14%–31%. Virtual asphalt pore networks were generated using the Intersected Stacked Air Voids (ISA) method, with its parameters being automatically adjusted by the means of a differential evolution optimisation algorithm, and then 3D printed using transparent resin. Permeability tests were conducted on the resin samples to understand the effects of pore topology on hydraulic conductivity. Moreover, the pore networks generated virtually were compared to real asphalt pore networks captured via X-ray Computed Tomography (CT) scans. The optimised ISA method was able to generate realistic 3D pore networks corresponding to those seen in asphalt mixtures in term of visual, topological, statistical and Air Void shape properties. It was found that, in the range of porous asphalt materials investigated in this research, the high dispersion in hydraulic conductivity at constant Air Void content is a function of the average Air Void diameter. Finally, the relationship between average Void diameter and the maximum aggregate size and gradation in porous asphalt materials was investigated.

K Ramamurthy - One of the best experts on this subject based on the ideXlab platform.

  • Air Void characterisation of foam concrete
    Cement and Concrete Research, 2007
    Co-Authors: E Kunhanandan K Nambiar, K Ramamurthy
    Abstract:

    Abstract The pore structure of cementitious material, predetermined by its porosity, permeability and pore size distribution, is a very important characteristic as it influence the properties of the material such as strength and durability. The pore parameter could therefore be a primary factor influencing the material properties of foam concrete and an in depth look into this aspect is required to establish relationships between this and material properties. In order to evaluate these relationships it was necessary to develop parameters to explain and quantify the Air‐Void structure of foam concrete. This paper discusses the investigations done to characterise the Air‐Void structure of foam concrete by identifying few parameters and influence of these parameters on density and strength. A camera connected to an optical microscope and computer with image analysis software were used to develop these parameters. It is found that out of the Air‐Void parameters investigated, volume, size and spacing of Air Voids have influence on strength and density. Mixes with a narrower Air‐Void size distribution showed higher strength. At higher foam volume merging of bubbles seems to produce larger Voids, results in wide distribution of Void sizes and lower strength. Air‐Void shape has no influence on the properties of foam concrete.

  • Air‐Void characterisation of foam concrete
    Cement and Concrete Research, 2007
    Co-Authors: E Kunhanandan K Nambiar, K Ramamurthy
    Abstract:

    Abstract The pore structure of cementitious material, predetermined by its porosity, permeability and pore size distribution, is a very important characteristic as it influence the properties of the material such as strength and durability. The pore parameter could therefore be a primary factor influencing the material properties of foam concrete and an in depth look into this aspect is required to establish relationships between this and material properties. In order to evaluate these relationships it was necessary to develop parameters to explain and quantify the Air‐Void structure of foam concrete. This paper discusses the investigations done to characterise the Air‐Void structure of foam concrete by identifying few parameters and influence of these parameters on density and strength. A camera connected to an optical microscope and computer with image analysis software were used to develop these parameters. It is found that out of the Air‐Void parameters investigated, volume, size and spacing of Air Voids have influence on strength and density. Mixes with a narrower Air‐Void size distribution showed higher strength. At higher foam volume merging of bubbles seems to produce larger Voids, results in wide distribution of Void sizes and lower strength. Air‐Void shape has no influence on the properties of foam concrete.

Marek Zielinski - One of the best experts on this subject based on the ideXlab platform.

  • Air Void system and frost salt scaling of concrete containing slag blended cement
    Construction and Building Materials, 2009
    Co-Authors: Z Giergiczny, Michal A Glinicki, M Sokolowski, Marek Zielinski
    Abstract:

    Abstract The experimental investigation on the frost-salt scaling resistance of Air-entrained concrete containing CEM II/B-S 42.5N and CEM III/A 42.5N-HSR/NA slag-blended cements was performed. The Air Void system in concrete was evaluated in fresh concrete using AVA and in hardened concrete using an automated image analysis procedure. The mass of scaled material was increased for an increased slag content, in spite of increased compressive strength and flexural strength, decreased water absorption and decreased depth of water penetration of concrete. Increasing slag content resulted in a decrease of the total volume of Air in hardened concrete and in a corruption of the Air Void system exhibited by a decrease of micropores content. The increase of mass of scaled material was proportional to the increase of the spacing factor of Air Voids, except for CEM III/A cement concrete exhibiting accelerated scaling.

  • Air Void system in concrete containing circulating fluidized bed combustion fly ash
    Materials and Structures, 2008
    Co-Authors: Michal A Glinicki, Marek Zielinski
    Abstract:

    The increased use of advanced coal-burning technologies for power generation, such as circulating fluidized bed combustion (CFBC), results in new waste products. The potential for using CFBC fly ash in Air-entrained concrete was investigated in order to assess the influence of CFBC fly ash on the microstructure of Air Voids in hardened concrete. A special specimen surface preparation technique for contrasting the image and enabling measurements of Air Voids size and distribution using an automated image analysis procedure was used. The microstructure of Air Voids was evaluated on the basis of the total Air content, the spacing factor, and the specific surface of Air Voids. It was found that a satisfactory Air Void system in concrete could be produced when using CFBC fly ash for partial replacement of cement. The Air-Void system was characterized by a decreased specific surface of Voids and an increased spacing factor.