Investigating the Relationship of As-Constructed Asphalt Pavement Air Voids to Pavement Performance

2021 ◽  
Author(s):  
Michael Heitzman ◽  
Carolina Rodezno ◽  
Fabricio Leiva ◽  
Fan Gu ◽  
Gary Elkins ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Pavement Performance ◽  
Air Voids ◽  
Relationship Of ◽  
The Relationship

A New Method of Gradation Design about Rutting Resistance of Asphalt Pavement

2010 ◽  
Vol 168-170 ◽  
pp. 2397-2401
Author(s):  
Bao Lin Zhu ◽  
Xin Huang ◽  
Yan Ping Jing
Keyword(s):  
Particle Size ◽  
Prediction Model ◽  
Packing Density ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Air Voids ◽  
Aggregate Packing ◽  
Continuous Particle ◽  
The Relationship

The article derived the formula of continuous particle size of asphalt aggregate packing density based on the Stovall model; according to the relationship between porosity and rutting, rutting prediction model was established; by experiment to determine the parameters in the formula to be determined , and the applicability of the formula was verified, the results showed that: the formula can calculate air voids and dynamic stability of asphalt mixture by aggregate size distribution and the aggregate ratio .

Temperature–density relationship of hot-mix asphalt pavement after completed rolling

2008 ◽  
Vol 35 (12) ◽  
pp. 1468-1475 ◽  
Author(s):  
Awad S. Hanna ◽  
Min-Jae Lee ◽  
Stephen M. Schoenfelder ◽  
Chanyoung Lee
Keyword(s):  
Cold Rolling ◽  
Hot Mix Asphalt ◽  
Asphalt Pavement ◽  
Explanatory Model ◽  
Density Relationship ◽  
Theory Research ◽  
Relationship Of ◽  
The Relationship ◽  
Significant Factors

This study investigates the relationship between the density and temperature of newly placed hot-mix asphalt pavement, and attempts, using both field and laboratory-based data, to validate the theory that as asphalt cools it becomes denser. Hence, if a nuclear gauge is used to measure asphalt density, it should record a higher reading after the asphalt has been allowed to cool overnight than when the asphalt density was first measured just after cold rolling the previous day. This research investigation has found a model that does not reinforce this theory. Research has shown that testing a road for density the morning after paving, as opposed to the same day, does not result in a significant increase in density. In addition, this study found significant factors that impact pavement density, and developed an explanatory model to estimate pavement density.

scholarly journals Investigation of the Responses of Asphalt Pavement Structure Considering Load - Poisson's Ratio Relation

2012 ◽  
Vol 5 ◽  
pp. 230-237
Author(s):  
Lei Zhang ◽  
Yi Qiu Tan ◽  
Yang Jian Ou ◽  
Xiang Bing Gong
Keyword(s):  
Finite Element ◽  
Poisson’S Ratio ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Poisson's Ratio ◽  
Pavement Structure ◽  
Relationship Of ◽  
The Relationship ◽  
Poisson's Ratios

Abstract. Poisson’s ratio is one of the important parameters that can be used to reflect the deformation characteristics of solid materials. To further understand the mechanical behaviors of materials and improve the accuracy of the finite element simulation results, the Poisson’s ratio must be defined accurately. In this paper, DIC technology is employed to investigate the Poisson’s ratios of asphalt mixtures under the different gradation and different compaction conditions. It is found that the Poisson’s ratios of different asphalt mixture are quite different and the number of compaction had a greater influence on Poisson’s ratio. It also showed that Poisson’s ratio of asphalt mixture was not a constant under the 25°C temperature condition, but varied with load. The experiment data suggested that the curve of the load - Poisson’s ratio could be divided into three sections through the observation of the graph and it also could be used to investigate the properties of asphalt mixtures deformation resistance. General-purpose finite element software is used to simulate the different contact pressure and Poisson’s ratio under dynamic loading condition, in order to find the response of asphalt pavement structure based on the relationship between load and Poisson’s ratio. It was found that the relationship of load - Poisson’s ratio significantly affected the response of asphalt pavement. It meant that the relationship of load - Poisson’s ratio should be considered when designing the asphalt pavement to improve the asphalt pavement service life.

scholarly journals RELATING FLEXIBLE PAVEMENT ACCEPTANCE CRITERIA TO PERFORMANCE USING MEPDG SIMULATIONS AND PIECEWISE CUBIC SPLINE INTERPOLATION / LANKSČIŲJŲ DANGŲ ATRANKOS KRITERIJŲ SUSIEJIMAS NAUDOJANT MEPDG MODELIUS IR DALINĘ KUBINĘ SPLAININĘ INTERPOLIACIJĄ

2012 ◽  
Vol 18 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Anshu Manik ◽  
Karim Chatti ◽  
Kasthurirangan Gopalakrishnan
Keyword(s):  
Spline Interpolation ◽  
Fatigue Cracking ◽  
Flexible Pavement ◽  
Pavement Performance ◽  
Air Voids ◽  
Field Investigations ◽  
The Relationship

The performance of the highway system is inevitably linked to its quality of design and construction. To control the quality of construction, elaborate Quality Assurance (QA) programs have been developed by highway agencies based on statistical sampling and acceptance procedures to ensure that the work is in accordance with the plans and specifications. The QA procedure is intended to ensure that the constructed pavement would perform well during its design life. However, numerous field investigations and research studies over the years have identified a gap in our understanding of the relationship between the QA test results and pavement performance (fatigue cracking, rutting, etc.). This paper is intended to present the framework for developing an understanding of the relationship between QA tests and flexible pavement performance, which is essential for developing Performance Related Specifications (PRS). In the first part of the paper, the Michigan Department of Transportation's (MDOT) QA program and Long-Term Pavement Performance (LTPP) databases were used to empirically investigate any relationship between key QA variables and various pavement performance measures. In the second part of the paper, the Mechanistic-Empirical Pavement Design Guide (MEPDG) software was used together with an accurate and efficient interpolation technique to develop many simulations for the purpose of showing the effect of variability in QA parameters including plant air voids, in-situ density and asphalt content on flexible pavement performance. Santrauka Greitkelių sistemos darbas (funkcionavimas) yra neišvengiamai susijęs su jo projektavimo ir statybų kokybe. Greitkelių agentūros, remdamosi statistinėmis atrankos ir ėmimo procedūromis, parengė kokybės užtikrinimo (KU arba QA) programas, kad būtų kontroliuojama statybų kokybė ir užtikrinamas darbas pagal planus ir specifikacijas. KU (QA) procedūra siekiama užtikrinti, kad pagaminta danga gerai funkcionuotų projekte nurodytą laiką. Tačiau metams einant, atlikus daugybę natūrinių ir mokslinių tyrimų, buvo nustatytas didelis santykio tarp KU (QA) bandymų rezultatų ir dangos darbo (funkcionavimo) (plyšių atsiradimo dėl nuovargio, provėžų ir kt.) vertinimo skirtumas. Šiame darbe skatinama plėtoti supratimą apie ryšius tarp KU (QA) bandymų ir lanksčiųjų dangų funkcionavimo, kuris yra nepaprastai svarbus kuriant su darbu (funkcionavimu) susijusias specifikacijas (PRS). Pirmoje darbo dalyje buvo naudojamos Mičigano transporto departamento (MDOT) KU (QA) programos ir ilgalaikės dangos darbo (funkcionavimo) (LTPP) duomenų bazės, siekiant empiriškai ištirti bet kuriuos santykius tarp pagrindinių KU (QA) kintamųjų ir įvairių dangų darbo matavimų. Antroje darbo dalyje buvo naudojama mechanistinio ir empirinio dangų projektavimo vadovo (MEPDG) programinė įranga kartu su tikslia ir efektyvia interpoliacijos technika, siekiant sukurti modelius, kuriuose perteiktas KU (QA) parametrų kintamumo poveikis lanksčiųjų dangų funkcionavimui, įskaitant augalų oro ertmes, vietinį tankį ir asfalto sandarą.

The Mechanical Characteristics of the under Layer of Pavement of Large-Stone Asphalt Mixes

2012 ◽  
Vol 598 ◽  
pp. 631-634 ◽  
Author(s):  
Hui Xia Li ◽  
Shen Jia Tong
Keyword(s):  
Asphalt Pavement ◽  
Temperature Stability ◽  
Effect Of Temperature ◽  
High Temperature Stability ◽  
Asphalt Mixes ◽  
Reflection Cracking ◽  
Large Stone ◽  
Base Course ◽  
Relationship Of ◽  
The Relationship

The Large-stone Asphalt Mixes (LSM)is adopted to solve the problems of the inadequate rutting resistance and poor durability to the asphalt pavement because of the good properties of high temperature stability and eliminating the reflection cracking. As under layer of asphalt pavement the Large-stone Asphalt Mixes is less researched than base course. The mechanical properties of every pavement layer can be analyzed under the effect of temperature and load coupling when the height of LSM (Large-Stone Asphalt Mixes) is different. Combined the properties with the demand of structure and the relationship of the layer and maximum nominal diameter, recommend the resonable height of the LSM.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

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