Impact resonance testing is a well-documented non-destructive testing method and its applications on asphalt concrete have also been implemented successfully. The test is carried out manually by inducing an impact in order to excite the test specimen and taking measurements of the vibrational response. In an effort to improve the manual procedure of impact resonance testing, an automated non-contact methodology is developed and its applicability with regards to low temperature behaviors of asphalt concrete is investigated. Results from this work show that repeatable fundamental resonance frequency measurements can be performed on a disc shaped specimen in an automated manner without the need to open the thermal chamber. The measurements obtained from the new method have been verified by taking similar resonance frequency measurements using an instrumented impact hammer. It has also been shown in this work that the proposed method is suitable to investigate the lone effects of cyclic thermal conditioning on asphalt concrete without any other possible biasing effects associated with contact in the conventional testing. A hysteretic behavior of stiffness modulus is obtained on three different asphalt concrete specimens subjected to repeated low temperature cyclic conditioning. Reduced modulus values at each temperature are obtained in all the tested specimens after a low temperature stepwise conditioning at temperatures from 0oC to -40 oC. This observed behavior shows that the dynamic modulus of the tested specimens is affected by low temperature conditioning. The norm of the complex modulus decreases and the phase angle or damping ratio increases after low temperature conditioning. Hence, valuable and practical low temperature characteristics of different asphalt concrete mixtures can possibly be obtained by using the proposed methodology.

In this study, the effect of pipe-soil relative stiffness on the behaviour of buried flexible pipes was investigated considering the pipe size, material type, stiffness, pipe-soil and natural soil-backfill interfaces and geometry of the trench using the finite element method. For this purpose, a parametric study was conducted to examine the effect of different variables on the resulting earth loads and deformations imposed on the buried pipes. Various types of trench pipe-soil cases were analysed for a certain natural ground and backfill material by the PLAXIS finite element code which allows simulating non-linear soil behaviour, the stages of construction as well as the pipe-soil interaction aspects of the problem. Loads and deformations obtained by the finite element method were compared with those calculated by the conventional approaches for different pipe-soil stiffness ratios. The finite element results obtained for the deformation of typically flexible Polyethylene pipes were then used to back-calculate the range of modulus of soil reaction, E&#039 / , values for various pipe-soil relative stiffness and they were compared with the suggested value proposed by Howard (1977).

Cette thèse traite de l’effet des grilles en fibre de verre, utilisées pour renforcer les structures routières, sur la liaison entre deux couches d’enrobés bitumineux, la durée de vie en fatigue et le module de rigidité des ´éprouvettes cylindriques renforcées, ainsi que sur les déflexions mesurées sur une section de route renforcée in situ. Des essais de cisaillement (LEUTNER) ainsi que de module et de fatigue (ITT) ont été conduit sur des éprouvettes renforcées et non renforcées en utilisant différentes grilles, différentes émulsion ainsi que différentes quantités d’émulsion. Pour ces essais, une surface de test a été construite in-situ, de laquelle les ´éprouvettes ont ´été extraites. Une section de route in-situ a ´également été construite, renforcée avec 3 différentes grilles et avec deux sections de références. Les déflexions de la chaussée ont été déterminées avant et après les travaux. Une modélisation de la structure a été faites basée sur les résultats des mesures de déflexion. / This PhD-study evaluates the impact of glass fibre grids, used to reinforced asphalt structures, on the bonding between two asphalt layers, the fatigue life and the stiffness modulus of reinforced cylindrical specimens as well as on the deflections measured on a reinforced in-situ road section. Shear tests (LEUTNER) as well as modulus-tests and fatigue-tests (ITT) were conducted on reinforced and unreinforced specimens, using different grids, different emulsions and different emulsion quantities. For this tests, an outdoor test-surface was constructed, from which the specimens were extracted. A in-situ road test section was also constructed, reinforced with 3 different grids and having two reference sections. The deflections of the road were determined before and after the construction works. A modelisation of the structure, based on the deflection measurements, was made.

The diploma thesis is focused on the testing of asphalt mixtures of asphalt concrete containing reclaimed asphalt and laying of the test section. The theoretical part deals with the use of reclaimed asphalt in hot asphalt mixtures, namely the specifics of rejuvenating agents, aging and asphalt mixture. Further more information on the functional properties of asphalt mixtures and the influence of reclaimed asphalt on them is given. The practical part describes testing of mixtures of ACO 11+ and ACO 11+ with 50% reclaimed asphalt and tests on asphalt binders. In order to compare the proposed mixtures, the low thermal properties of ČSN EN 12697-46 and the stiffness modules according to ČSN EN 12697-26. In the last part of the diploma thesis the results of the measured values were compared with each other in order to determine of asfphalt recovery. From the overall test results, it can be seen that the effect of the rejuvenating agent was positive. However, the desired degree of rejuvenation has not been achieved after production.

The diploma thesis deals with technology for the implementation and use of asphalt concrete for very thin layers (BBTM) with use of asphalt binder of high-polymer modification (HiMA). Further, there are described selected and performed functional tests. Thesis also contains design of a mixture for bituminous concrete type targeted for very thin layers with different types of binders. After a suitable design of the mixture, laboratory tests were carried out (stiffness modulus, resistance to permanent deformation, low temperature characteristics, water resistance and particle loss). The output of this work is a set of measured values and processed results with their interpretation.

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.

The asphalt mixture BBTM 5 A with crumb rubber modified bitumen (CRmB) is designed and produced in the diploma thesis. The influence of CRmB content on low temperature properties, stiffness and fatigue of asphalt mixture BBTM 5 A is determined. The influence of asphalt mixture ageing simulation on change of low temperature properties is also evaluated.

This work is focused on the design and determination of the properties of porous asphalt and asphalt concrete for very thin layers with TecRoad addition. The water sensitivity, particle loss, stiffness, fatigue and low temperature characteristics and resistance to permanent deformation are determined for a description of mixtures properties. Subsequently, the mixtures are compared and recommendations for use in maintenance and reconstruction of roads are prepared.

This master's thesis describes how to use the asphalt layer called Stress Absorbing Layer (SAL) and comparises it with other types of SAL with different types of asphalt binders. In the first theoretical part is SAL generally described. In the second part is SAL practically tested and described.

Aim of this thesis is the usage of the open-graded asphalt concrete filled with a special cement grout in the road structures. Thesis defines the main concrete properties and explains related legislation and norms that apply. In addition, laboratory design of asfalt mixtures and a tree kind mortal filler and possibilities of mortal filler pigmentation are dealth with. Finally, thesis evaluates the results from various laboratory tests that were performed on the specimens made from final mixtures.