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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Využití polymerů do konstrukcí vozovek pozemních komunikací / Use of polymers in road constructions

Klusková, Jana January 2020 (has links)
The diploma thesis deals with the use of recycled polymers in asphalt mixtures. In the theoretical part of the thesis there is discussed the global issue of plastic waste including the experience of foreign countries, where this technology has already been introducted and used. The practical part is devoted to the proposal of using recycled plastic in asphalt mixture, description of used laboratory tests and the evaluating the effect of low-density polyethylen (LDPE) on the asphalt mixture type AC. There were performed tensile strenght tests, water resistant tests and stiffness modulus tests in the laboratory (E). The output of this work is an evaluation of measured values, processing of results and their interpretation depending on the possible use of this technology in Czech republic.
32

Problematika zvyšování podílu R - materiálu v asfaltových směsích / The issue of increasing the proportion of reclaimed asphalt in asphalt mixtures

Urbanec, Luboš January 2013 (has links)
The subject of this Ing. thesis is asphalt mixture with increasing RAP (Reclaimed Asphalt Pavement). The theoretical part defines the terms of recycling and RAP and types of recycling. The practical part is devoted to the production and testing of asphalt mixtures with different volume RAP. The proposed asphalt mixture is asphalt concrete for base layer ACP22 +. Content of RAP in mixtures is 0%, 30%, 50% and 70%. As a special additive to soften the asphalt from RAP is used ingredient STORFLUX. For each mixture are established modulus stiffness of asphalt mixture and determined fatigue characteristics of asphalt mixture. The identified properties are compared for the different representation of RAP.
33

Evaluation of Asphalt Field Cores with Simple Performance Tester and X-ray Computed Tomography

Farcas, Florentina Angela January 2012 (has links)
The importance of aggregate structure and air voids distribution for asphalt mixture rutting and cracking performance has been well established on the basis of experience and is well documented in the literature. Past and current investigations are limited to assessment of performance based on macroscopic behavior due to the difficulty associated with the quantitative measurement and analysis of the internal structure of asphalt mixtures. Lately, technical advances in X-ray Computed Tomography (CT) and image processing and analysis has made possible to bring the attention also to the internal structure of asphalt mixtures. SPT results from asphalt field cores, including dynamic modulus (before and after loading) and microstrain accumulation (flow number), exhibited significant variability; most likely, induced by irregularities in the core shape. The analysis of aggregate structure and air voids distribution performed trough X-ray CT, clearly identified segregation in the asphalt mixture as a key factor that induced variability in SPT results. / QC 20120320
34

Recyklace asfaltových směsí s vyšším množstvím R-materiálu / Recycling of asphalt mixtures with higher amount of RAP

Klimek, Matěj January 2022 (has links)
The theoretical part of the diploma thesis recapitulates the existing literature in the field of recycling asphalt mixtures with a higher content of RAP (Reclaimed asphalt pavement). The practical part of the diploma thesis examines changes in the properties of asphalt mixtures with a higher content of RAP, due to changes in mixing time. Five mixtures have been proposed for this research. It is an asphalt mixture intended for the road abrasive layer (ACO 11+). Reference mixture "A" without RAP, with a standard mixing time of 25 seconds. Mixture "B" with 40% RAP, without rejuvenator, with an extended mixing time of 40 seconds. Mixture "C" with 40% RAP, with rejuvenator and standard mixing time. Mixture "D" with 40% RAP with rejuvenator and extended mixing time of 40 seconds. Mixture "E" with 40% RAP, with rejuvenator and extended mixing time of 55 seconds.
35

Využití polymerů do konstrukcí vozovek pozemních komunikací / Use of polymers in road constructions

Klusková, Jana Unknown Date (has links)
The diploma thesis deals with the use of recycled polymers in asphalt mixtures. In the theoretical part of the thesis there is discussed the global issue of plastic waste including the experience of foreign countries, where this technology has already been introducted and used. The practical part is devoted to the proposal of using recycled plastic in asphalt mixture, description of used laboratory tests and the evaluating the effect of low-density polyethylen (LDPE) on the asphalt mixture type AC. There were performed tensile strenght tests, water resistant tests and stiffness modulus tests in the laboratory (E). The output of this work is an evaluation of measured values, processing of results and their interpretation depending on the possible use of this technology in Czech republic.
36

Evaluation of the Ohio CTE Device for Low Temperature Characterization of Hot Mix Asphalt

Nassar, Saif 25 August 2020 (has links)
No description available.
37

Etude et modélisation des renforcements de chaussées à l'aide de grilles en fibre de verre sous sollicitations de fatigue / Study and modeling of road reinforcements with glass fiber grids under fatigue loading

Arsenie, Ioana maria 29 November 2013 (has links)
L’objectif de la thèse « Etude et modélisation des renforcements de chaussées à l’aide de grilles en fibre de verre sous sollicitations de fatigue » est de caractériser le rôle du renforcement de la couche de surface en béton bitumineux d’une structure de chaussée soumise à des sollicitations de fatigue au moyen d’une grille en fibre de verre appelée « géo-grille ». Le comportement en fatigue du composite formé de béton bitumineux et de géo-grille est étudié en laboratoire par des essais de flexion en quatre points (4PB), pilotés en déformation avec un chargement sinusoïdal alterné, à 10°C et 25 Hz. Les éprouvettes testées sont des poutres prismatiques de grandes dimensions 630 x 100 x 100 mm3. Elles sont de deux types : en béton bitumineux (non-renforcées) et en béton bitumineux renforcé par deux géo-grilles (renforcées). Le dispositif d’essais est un banc de fatigue en flexion en quatre points prototype, qui respecte les normes européennes. Les résultats expérimentaux ont été utilisés dans la modélisation de l’évolution de l’endommagement en fatigue de deux types d’éprouvettes. Les lois d’endommagement des matériaux de type Bodin sont implantées dans le code aux éléments finis CAST3M. Deux catégories de modèles ont été conçues, respectivement monocouche et tri-couches. Chaque catégorie comprend un modèle de poutre non-renforcée et un modèle de poutre renforcée. Le modèle de Castro-Sanchez a été testé pour prédire l’endommagement et notamment le nombre de cycles à la rupture pour chaque type de poutre. / The objective of the PhD thesis « Study and modelling of the pavement reinforcement with glass fibre grid under fatigue loading » is to characterize the reinforcement role of the asphalt surface layer of a pavement subjected to fatigue loading with the glass fibre grid or « geo-grid ». The fatigue behaviour of the composite formed of asphalt mixture and geo-grid is studied in laboratory with four point bending tests (4PB) performed with sinusoidal waveform, at 10°C and 25 Hz. The tested specimens are 630 x 100 x 100 mm3 beams of two types: asphalt beams (non-reinforced) and asphalt beams reinforced with geo-grid (reinforced). A four point bending prototype device was designed to perform the fatigue tests on the big size asphalt specimens. The device respects the European Standards. The experimental results were used for modelling of the damage evolution under fatigue loading of the both types of beams. The damage laws of the materials are Bodin laws programmed in Cast3M finite element code. Two categories of models were conceived, respectively: one layer beam models and tri-layers beam models. Each category has a model of non-reinforced beam and a model of reinforced beam. Furthermore, Castro-Sanchez model was used to predict damage evolution and in particular the number of cycles to failure correspondent to the two types of beams.
38

Návrh a posouzení asfaltového betonu pro ložní vrstvy s asfaltem modifikovaným pryžovým granulátem / Design and evaluation of asphalt rubber mixture for pavement binder course

Musílek, Lukáš January 2013 (has links)
The design of asphalt concrete for binder courses with high-viscosity asphalt rubber and low-viscosity asphalt rubber is carried out in the diploma thesis. Selected performance tests (low temperature characteristics, stiffness and fatigue) and water sensitivity are performed for these mixtures. Results are compared each other.
39

Asfaltocementový beton / Open-graded asphalt concrete filled with a special cement grout

Lutonský, Filip January 2013 (has links)
The thesis is aimed at deepening knowledge about the design and use of open-graded asphalt concrete filled with a special cement grout. The first part is the issue discussed theoretically with reference to the real possibility of practical application, a description of the various manufacturers and their patented technologies. The second part of this work is devoted to assess the resistance of this technology to chemical de-icing agents.
40

Návrh a posouzení směsi pro asfaltové vrstvy se zvýšenou odolností proti šíření trhlin (SAL) / Desing and evaluation of Bituminous Stress Absorbing Pavement Layer

Coufalík, Pavel January 2013 (has links)
This master's thesis deals with the possibility of special asphalt-rubber mixture using - Stress Absorbing Layer (SAL). In the theoretical part the SAL and test methods are described. In the practical part, several different mixtures are designed and selected mixtures were tested. Low-temperature characteristics, permanent deformations, bending tensile relaxation, stiffness modulus and fatigue properties were determined. Based on the test results the mixtures were compared and their benefit is evaluated according to Performance Pavement Design Method, the pavement structure was evaluated by using of computer programme LayEps.

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