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Youngsoo Richard Kim - One of the best experts on this subject based on the ideXlab platform.

  • Introdução do coeficiente de uniformidade para avaliação de revestimentos asfálticos do tipo tratamentos superficiais
    Associação Nacional de Pesquisa e Ensino em Transportes (ANPET), 2018
    Co-Authors: Raimi Costa Da Silva, Suelly Helena De Araújo Barroso, Youngsoo Richard Kim
    Abstract:

    The surface treatments are the most used type of coating in Brazil in Low Traffic Volume Roads, more specifically the chip seal. After field and laboratory investigations, it was observed that the main defects of chip seals are Aggregate Loss (or raveling) and bleeding, which can affect its performance and increase considerably the paving costs. In Brazil there are still few studies of design and performance of chip seals in the laboratory phase to predict these two defects. Thus, it was investigated materials and methodologies employed at North Carolina State University and it was verified that the coefficient called Performance-Based Uniformity Coefficient (PUC) is a parameter associated with the granulometric distribution of the Aggregate that has potential to predict bleeding and raveling of this type of coating. It was concluded that PUC is an excellent parameter to be introduced in chip seal design procedures and that the ranges recommended by DNIT to chip seals should be reviewed

  • Performance-Based Uniformity Coefficient of Chip Seal Aggregate
    Transportation Research Record, 2009
    Co-Authors: Jusang Lee, Youngsoo Richard Kim
    Abstract:

    Development of a new chip seal performance indicator called the performance-based uniformity coefficient (PUC) is presented. The PUC uses the concepts of McLeod's failure criteria for chip seals and the uniformity coefficient used for soil, sand, and Aggregate. The Aggregate Loss performance test, using the third-scale model mobile loading simulator, is used for evaluating the PUC. Results demonstrate that the methodology introduced in this research and McLeod's failure criteria can be excellent tools for narrowing the Aggregate specifications required for chip seal construction. In addition to these results, the PUC, which is a gradation-based performance indicator, is an improvement over the previous uniformity coefficient for chip seal construction. The PUC can also aid in Aggregate selection for the chip seal, and it can ease and clarify engineering communications within the chip seal industry.

  • understanding the effects of Aggregate and emulsion application rates on performance of asphalt surface treatments
    Transportation Research Record, 2008
    Co-Authors: Jusang Lee, Youngsoo Richard Kim
    Abstract:

    Presented are the effects of Aggregate and emulsion application rates on the performance of asphalt surface treatments (ASTs), as evaluated by the third-scale Model Mobile Loading Simulator (MMLS3) and digital image processing. Performance characteristics evaluated in this study include Aggregate Loss and bleeding. Lightweight Aggregate and granite Aggregate with different gradations were used with CRS-2 emulsion to design the various combinations of Aggregate and emulsion application rates. The MMLS3 test protocol was applied to these AST specimens, and performance measurements were analyzed as a function of the application rates. Results demonstrated that the new AST performance test method introduced in this study was an excellent means of evaluating AST performance. It was found that the major factor affecting AST performance was Aggregate gradation. Also, a method was developed to determine the optimum Aggregate and emulsion application rates from the MMLS3 test results. The optimum rates determined from this method were confirmed by a blind test performed by bituminous supervisors and road maintenance unit engineers at the North Carolina Department of Transportation. Finally, results from this study were used to study the voids concept, which serves as the foundation for AST mix design. It was concluded that the reference voids (the compacted voids resulting from MMLS3 trafficking) depend on the voids in the loose Aggregate that are, in turn, affected by the Aggregate gradation type.

Krzysztof Burnecki - One of the best experts on this subject based on the ideXlab platform.

  • stable weak approximation at work in index linked catastrophe bond pricing
    Risks, 2017
    Co-Authors: Krzysztof Burnecki, Mario Nicolo Giuricich
    Abstract:

    We consider the subject of approximating tail probabilities in the general compound renewal process framework, where severity data are assumed to follow a heavy-tailed law (in that only the first moment is assumed to exist). By using the weak convergence of compound renewal processes to α -stable Levy motion, we derive such weak approximations. Their applicability is then highlighted in the context of an existing, classical, index-linked catastrophe bond pricing model, and in doing so, we specialize these approximations to the case of a compound time-inhomogeneous Poisson process. We emphasize a unique feature of our approximation, in that it only demands finiteness of the first moment of the Aggregate Loss processes. Finally, a numerical illustration is presented. The behavior of our approximations is compared to both Monte Carlo simulations and first-order single risk Loss process approximations and compares favorably.

  • stable weak approximation at work in index linked catastrophe bond pricing
    Social Science Research Network, 2017
    Co-Authors: Mario Nicolo Giuricich, Krzysztof Burnecki
    Abstract:

    We consider the subject of approximating tail probabilities in the general compound renewal process framework, where severity data are assumed to follow a heavy-tailed law (in that only the first moment is assumed to exist). By using weak convergence of compound renewal processes to Levy motion, we derive such weak approximations. Their applicability is then highlighted in the context of an existing, classical, index-linked catastrophe bond pricing model, and in doing so we specialise these approximations to the case of a compound time-inhomogeneous Poisson process. We emphasise a unique feature of our approximation, in that it only demands finiteness of the first moment of the Aggregate Loss processes. Finally, a numerical illustration is presented. The behaviour of our approximations is compared to both Monte Carlo simulations and first-order single risk Loss process approximations, and compares favourably.

Mario Nicolo Giuricich - One of the best experts on this subject based on the ideXlab platform.

  • stable weak approximation at work in index linked catastrophe bond pricing
    Risks, 2017
    Co-Authors: Krzysztof Burnecki, Mario Nicolo Giuricich
    Abstract:

    We consider the subject of approximating tail probabilities in the general compound renewal process framework, where severity data are assumed to follow a heavy-tailed law (in that only the first moment is assumed to exist). By using the weak convergence of compound renewal processes to α -stable Levy motion, we derive such weak approximations. Their applicability is then highlighted in the context of an existing, classical, index-linked catastrophe bond pricing model, and in doing so, we specialize these approximations to the case of a compound time-inhomogeneous Poisson process. We emphasize a unique feature of our approximation, in that it only demands finiteness of the first moment of the Aggregate Loss processes. Finally, a numerical illustration is presented. The behavior of our approximations is compared to both Monte Carlo simulations and first-order single risk Loss process approximations and compares favorably.

  • stable weak approximation at work in index linked catastrophe bond pricing
    Social Science Research Network, 2017
    Co-Authors: Mario Nicolo Giuricich, Krzysztof Burnecki
    Abstract:

    We consider the subject of approximating tail probabilities in the general compound renewal process framework, where severity data are assumed to follow a heavy-tailed law (in that only the first moment is assumed to exist). By using weak convergence of compound renewal processes to Levy motion, we derive such weak approximations. Their applicability is then highlighted in the context of an existing, classical, index-linked catastrophe bond pricing model, and in doing so we specialise these approximations to the case of a compound time-inhomogeneous Poisson process. We emphasise a unique feature of our approximation, in that it only demands finiteness of the first moment of the Aggregate Loss processes. Finally, a numerical illustration is presented. The behaviour of our approximations is compared to both Monte Carlo simulations and first-order single risk Loss process approximations, and compares favourably.

Samuel B Cooper - One of the best experts on this subject based on the ideXlab platform.

  • effects of emulsion types application rates and crumb rubber on the laboratory performance of chip seal
    Construction and Building Materials, 2020
    Co-Authors: Nafiur Rahman, Tanvir Ahmed Sarkar, Mostafa A Elseifi, Corey Mayeux, Samuel B Cooper
    Abstract:

    Abstract Chip sealing is a commonly used pavement maintenance method that aims to delay pavement deterioration by reducing water infiltration and restoring skid resistance. Loss of Aggregate and bleeding are considered the major failure mechanisms in chip seal, and therefore, are the main design criteria for this treatment method. The objective of this study was to evaluate the laboratory performance of chip seals prepared with different types of asphalt emulsions, application rates, and Aggregate blends. A newly introduced crumb rubber modified asphalt emulsion was evaluated that allows chip seal installation at the same temperature of a standard emulsion. Types of emulsion included a crumb-rubber modified asphalt emulsion (CRS-2TR), an asphalt rubber (AC20-TR), a polymer-modified emulsion (CRS-2P), and a conventional unmodified emulsion (CRS-2). Application rates were selected based on the Louisiana Department of Transportation and Development (LaDOTD) and the Texas Department of Transportation (TxDOT) specifications as well as from the chip seal design method recommended in NCHRP Report 680. A 90-10 Aggregate blend of lightweight Aggregate (LWA) and rubber Aggregate (RA) was also investigated. The Loss of Aggregate was measured using two laboratory performance tests: the sweep test (ASTM D 7000) and the Pennsylvania Aggregate Retention Test (PART). The strength of adhesion of the four emulsions was also evaluated using the Bitumen Bond Strength (BBS) test. While asphalt rubber was the best performer in terms of Aggregate Loss, CRS-2P and CRS-2TR performed similarly followed by the conventional emulsion. Results of the BBS test showed a similar rank for the bond strength of the emulsions. It was also observed that the Loss of Aggregates in chip seal decreased with the increase in application rate. However, incorporation of rubber as Aggregate in chip sealing increased the Loss of Aggregate in the specimens indicating poor adhesion between the emulsions and the rubber Aggregate.

Jusang Lee - One of the best experts on this subject based on the ideXlab platform.

  • Performance-Based Uniformity Coefficient of Chip Seal Aggregate
    Transportation Research Record, 2009
    Co-Authors: Jusang Lee, Youngsoo Richard Kim
    Abstract:

    Development of a new chip seal performance indicator called the performance-based uniformity coefficient (PUC) is presented. The PUC uses the concepts of McLeod's failure criteria for chip seals and the uniformity coefficient used for soil, sand, and Aggregate. The Aggregate Loss performance test, using the third-scale model mobile loading simulator, is used for evaluating the PUC. Results demonstrate that the methodology introduced in this research and McLeod's failure criteria can be excellent tools for narrowing the Aggregate specifications required for chip seal construction. In addition to these results, the PUC, which is a gradation-based performance indicator, is an improvement over the previous uniformity coefficient for chip seal construction. The PUC can also aid in Aggregate selection for the chip seal, and it can ease and clarify engineering communications within the chip seal industry.

  • understanding the effects of Aggregate and emulsion application rates on performance of asphalt surface treatments
    Transportation Research Record, 2008
    Co-Authors: Jusang Lee, Youngsoo Richard Kim
    Abstract:

    Presented are the effects of Aggregate and emulsion application rates on the performance of asphalt surface treatments (ASTs), as evaluated by the third-scale Model Mobile Loading Simulator (MMLS3) and digital image processing. Performance characteristics evaluated in this study include Aggregate Loss and bleeding. Lightweight Aggregate and granite Aggregate with different gradations were used with CRS-2 emulsion to design the various combinations of Aggregate and emulsion application rates. The MMLS3 test protocol was applied to these AST specimens, and performance measurements were analyzed as a function of the application rates. Results demonstrated that the new AST performance test method introduced in this study was an excellent means of evaluating AST performance. It was found that the major factor affecting AST performance was Aggregate gradation. Also, a method was developed to determine the optimum Aggregate and emulsion application rates from the MMLS3 test results. The optimum rates determined from this method were confirmed by a blind test performed by bituminous supervisors and road maintenance unit engineers at the North Carolina Department of Transportation. Finally, results from this study were used to study the voids concept, which serves as the foundation for AST mix design. It was concluded that the reference voids (the compacted voids resulting from MMLS3 trafficking) depend on the voids in the loose Aggregate that are, in turn, affected by the Aggregate gradation type.