Impact of Subgrade Strength on HMA Section Thickness

Flexible pavements are built from the soil up, and the quality and characteristics of each layer have a significant impact on performance. Soft soils and thin base layers can require thicker asphalt. Properly preparing and constructing asphalt bases can be a cost-effective way to achieve a perpetual pavement. In this session we will explore the impact of subgrade and base layers and how you can optimize pavement design for maximum performance

Identifying Pavement Failures and Effective Base Preparation

You are responsible for rehabilitating a pavement and need to do some patching. Where do you patch? How do you patch? You are building a new pavement from the ground up. How do you know you have a good platform? Come to this presentation and learn how to identify pavement failures, which methods are best used to repair them, and how to properly prepare from the ground up

Asphalt Mixture Design Concepts to Develop Aggregate Interlock

From the beginning of asphalt mixture design it was desired to understand the interaction of aggregates, asphalt, and the voids created during their compaction. In asphalt mixture design, guidance is lacking in the selection of the design aggregate structure and understanding the interaction of that aggregate structure and mixture volumetric properties. This paper presents mixture design concepts that utilize aggregate interlock and aggregate packing to develop an aggregate blend that meets volumetric criteria and provides adequate compaction characteristics. The presented concepts rely on coarse aggregate for the skeleton of the mixture with the proper amount of fine aggregate to provide a properly packed aggregate structure. The objective is to utilize aggregate packing concepts to analyze the combined gradation and relate the packing characteristics to the mixture volumetric properties and compaction characteristics. The presented concepts include an examination of aggregate packing and aggregate interlock, blending aggregates by volume, a new understanding of coarse and fine aggregate, and an analysis of the resulting gradation. This study presents comprehensive mix analysis concepts for developing and analyzing hot mix asphalt gradations. It is presented through a rational approach to the selection of relative amounts of coarse and fine aggregate. Evaluation of gradation with aggregate ratios provides a new tool for examining aggregate gradations. These ratios, based on particle packing, provide distinct relationships with the resulting mixture volumetrics and compaction characteristics. The results of this study improve the state-of-the-art in asphalt mix design and production by providing a method to characterize HMA mixture volumetrics and compaction characteristics through the fundamental principles of particle packing. The design concepts outlined in this study provide the foundation for a comprehensive asphalt mixture design method: The Bailey Method of Gradation Analysis and Asphalt Mix Design

Effect of aggregate gradation on the stiffness of asphalt mixtures

Aggregate gradation plays an important role in the behaviour of asphalt mixtures. Packing of aggregate is a very important factor that will be affected by changing the aggregate gradation. Many researchers have investigated different ways of describing packing both theoretically and practically. Bailey ratios have recently been used to understand the volumetric properties of mixtures. In this paper, the Bailey ratios have been used, and two further ratios have also been introduced to allow the asphalt mixture gradation to be fully understood. Thirteen different aggregate gradations have been chosen within the 14 mm asphalt concrete specification to investigate the effect of particle size distribution on the stiffness of the mixture. It was found that variation in aggregate gradation has a significant effect on asphalt stiffness, even within specification limits, and a reasonable correlation between the set of ratios investigated and the Indirect Tensile Stiffness

Incorporation of conductive nanoparticles into the polymeric solution and study of its rheological and electric parameters

71 stran, 5 stran příloh :ilustrace (některé barevné), tabulky, grafy +1 CD-ROMTato diplomová práce je zaměřena na tvorbu vláken a vlákenných struktur s inkorporovanými nanočásticemi vodivých polymerů. V teoretické části je popsána struktura polymerů, popis jejich výroby a jejich typických vlastností. Následuje hlavní téma - vodivé polymery, popsána je jejich historie, od samotného objevu až po současná využití a aplikace. U vybraných zástupců vodivých polymerů je popsána jejich struktura, popis přípravy a aplikace. V praktické části práce jsou popsány experimenty s vodivými polymery, od přípravy roztoků až po výsledné produkty tj. vlákna o rozměrech v řádech stovek nanometrů až jednotek mikrometrů, koaxiální vlákna, či vlákenné struktury.Prvotním záměrem této diplomové práce, je tvorba scaffoldů obsahujících vodivé polymery pro růst buněk, které je třeba při růstu stimulovat elektrickými vzruchy. Cílem této práce je vytvořit takové produkty, které naleznou uplatnění v reálném světě zejména ve zdravotnictví, či průmyslu, nebo dalším vědeckém poznání

RoSSBi3D: a 3D and bi-fluid code for protoplanetary discs

The diversity of the structures recently observed in protoplanetary discs (PPDs) with the new generation of high-resolution instruments have made more acute the challenging questions that planet-formation models must answer. The challenge is in the theoretical side but also in the numerical one with the need to significantly improve the performances of the codes and to stretch the limit of PPD simulations. Multi-physics, fast, accurate, high-resolution, modular, and reliable 3D codes are needed to explore the mechanisms at work in PPDs and to try explaining the observed features. We present RoSSBi3D the 3D extension of the 2D code Rotating-System Simulations for Bi-fluids (RoSSBi) which was specifically developed to study the evolution of PPDs. This is a new code, even if based on the 2D version, that we describe in detail explaining its architecture and specificity but also its performances against test cases. This FORTRAN code solves the fully compressible inviscid continuity, Euler, and energy conservation equations for an ideal gas in non-homentropic conditions and for pressureless particles in a fluid approximation. It is a finite volume code which is second order in time and accounts for discontinuities thanks to an exact Riemann solver. The spatial scheme accounts for the equilibrium solution and is improved thanks to parabolic interpolation which permits to reach third order in space. The code is developed in 3D and structured for high-performance parallelism. The optimised version of the code works on high performance computers with a very good scalability. We checked its reliability against a 2D analogue of sod shock tube test and tests specific to PPDs that includes Rossby wave instability (RWI), streaming instability (SI), dust capture by a vortex and dust settling. We release this code under the terms of the CeCILL2 Licence and make it publicly available.Comment: 17 pages, 14 figure

A treatment of fatiguester for following of the cyclic loading of photochromical substances

katedra: KTM; přílohy: 2 CD ROM; rozsah: 52Tato bakalářská práce se zabývá úpravou fatiguetesteru na přístroji Fotochrom 2. Teoretickou částí práce je rešerše o dosavadních poznatcích v oblasti fotochromních systémech, rešerše popisuje funkční barviva, aplikace funkčních barev a způsoby měření jejich vlastností. Praktická část bakalářské práce se zabývá popisem problému úpravy fatiguetesteru, dále je uveden návrh na řešení problému a popis jeho řešení. Následně jsou uvedeny a popsány nové funkce a aplikace na měřicím přístroji. Dále jsou zde uvedeny kontrolní výsledky nových funkcí a aplikací a výsledky kontrolního měření. Je zde uveden i návrh na další postup zlepší úpravy fatiguetesteru.This dissertation is concerned with a treatment of fatiguetester at an apparatus Fotochrom 2. A theoretical part of the dissertation is the exploration of facts about present pieces of knowledge in the photochromical system´s field. The exploration of facts describes the functional colouring-matter, application of the functional colouring-matter and a way of measuring of their characters. The practical part of the dissertation is concerned with problem´s describing of form of fatiguetester, further there is stated a proposal for solving a problem and describing of his solution. Afterwards there are stated follow-up outcomes of new functions and applications and outcomes of controling measuring. There is stated a proposal for further method of upgrading of fatiguetester´s form