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Tschegg E.K.,Vienna University of Technology | Jamek M.,Vienna University of Technology | Lugmayr R.,TenCate Geosynthetics
Road Materials and Pavement Design | Year: 2012

Geosynthetic interlayers in asphalt systems have become a convenient technology for lifetime prolongation in road construction engineering. Durability and lifetime prediction analysis of such systems can be obtained by fatigue crack growth testing. In this paper, the fatigue crack growth properties of three different asphalt interlayer system groups with different interlayer functions: SAMI (=Stress Absorbing Membrane Interlayer), asphalt reinforcement and the combination of SAMI + asphalt reinforcement are reported. For comparison non-interlayer systems (reference) have also been tested. Instead of 3- or 4-point bending tests with beams, wedge splitting tests with drill cores from the field are used for analyzing the fatigue crack growth behaviour of these systems. Due to the temperature dependence of asphalt the tests have been performed in a climate chamber at -10°C, 0°C and +10°C. Crack growth propagation was determined visually. The results show that this new visual approach for evaluation of crack growth testing together with the wedge splitting test are practicable, reproducible and allow grading of geosynthetic asphalt interlayer systems. © 2012 Taylor & Francis.

Douglas R.A.,Golder Ltd. | Laprade R.,TenCate Geosynthetics | Lawrence K.,Golder Ltd.
Transportation Research Record | Year: 2015

The heaviest trucks serving shovel-and-truck mining operations have tripled in weight to more than 600 tonnes gross weight over the past 30 years. The design of haul roads to support these trucks is becoming ever more challenging. An additional problem is the huge demand for aggregates with which to construct these thick, wide roads. In this study of the problem, a numerical modeling investigation was performed for a 300-tonnc-design axle on a granular pavement consisting of a capping layer, base, and subbase (0.5, 1.0, and 1.5 m thick, respectively). Conventional linearly elastic analyses and analyses not permitting tension were carried out. While the results of the conventional elastic analysis permitting tension had indicated that there was no reinforcing effect with these geotextiles, the results of the no-tension analysis indicated a significant reinforcement effect attributable to the inclusion of high-strength geotextiles in the cross section. The results bring into uues-tion the use of analyses permitting tension in the granular pavement materials.

Jamek M.,Vienna University of Technology | Tschegg E.K.,Vienna University of Technology | Lugmayr R.,TenCate Geosynthetics
Fatigue and Fracture of Engineering Materials and Structures | Year: 2012

Geosynthetic interlayers in asphalt systems have become a convenient technology for lifetime prolongation in road construction engineering. Established testing methods for characterizing construction materials can be used to describe and evaluate these innovative systems. This study compares three groups of asphalt interlayer systems (stress absorbing membrane interlayer = SAMI, asphalt reinforcement, SAMI + asphalt reinforcement) represented by 10 different geosynthetic interlayers in terms of crack growth resistance and strength. The results will be presented in relation to asphalt reference systems without interlayer. The mechanical and fracture-mechanical properties were determined by means of the wedge splitting test (WST) according to Tschegg and partially by the pull-out test. Due to temperature dependences of the material properties of asphalt, the tests have been performed at -10 °C, 0 °C and +10 °C specimen temperature. © 2012 Blackwell Publishing Ltd.

Artieres O.,TenCate Geosynthetics
Optics InfoBase Conference Papers | Year: 2010

A textile fibre optics composite sensor aims to monitor geotechnical structure and to generate early warnings if it detects and localizes the early signs of malfunctioning, such as leaks or instability. This is a customizable solution: Fiber Bragg gratings, Brillouin and Raman scattering can be built into this system. These technologies measure both strain and temperature changes in soil structures. It can provide a leak and deformation location within accuracies resp. 0.02% and 1 l/min/m. © 2010 Optical Society of America.

Perkins S.W.,Montana State University | Christopher B.R.,Christopher Consultants | Lacina B.A.,TenCate Geosynthetics | Klompmaker J.,BBG Bauberatung Geokunststoffe GmbH and Co.KG
International Journal of Geomechanics | Year: 2012

Mechanistic-empirical modeling and design solutions have been routinely used for conventional flexible pavements and have recently entered mainstream design practice through the issue of AASHTO design software. Recent work has been performed to incorporate mechanisms of base reinforcement with geosynthetics into mechanistic-empirical modeling and design. The purpose of this paper is to examine the use of this work for mechanistic-empirical modeling of reinforced unpaved roads by using the same model components used for paved roads and incorporating new components that account for the significant influence of pore-water pressure generation in the subgrade. Results from instrumented unpaved road test sections are used to calibrate and compare with the model predictions. The model provides reasonable predictions of rutting behavior for test sections where rut development is stable, where stable is defined as a rate of rutting that decreases with increasing traffic. The importance of excess pore-water pressure development in the subgrade is illustrated by the test sections and accounted for by the inclusion of steps in the model.© 2012 American Society of Civil Engineers.

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