Green-geo-engineering with geosynthetic reinforced soil structures is of increasing practice around the world. Poland is among the leading countries with the third biggest geogrid market in Europe. The German EBGEO 2010 Guideline for Soil Reinforcement with Geosynthetics as first European Guideline for Geosynthetics linked to the Eurocode 7, and the new design code for Japanese railway structures under seismic loading are introduced. New research results from the Geotechnical Institute of the RWTH Aachen, Germany, dealing with the soil/reinforcement interaction and new approaches for design codes for the reinforcement of base courses in traffic areas based on lab and field tests in the USA are presented.

This paper presents the results of an extensive investigation of asphalt concrete beams with geosynthetics interlayer. The subject of the research is an evaluation of infl uence of geosynthetics interlayer applied to bituminous samples on their fatigue life. The results of the tests evidences that when geosynthetics are used, the fatigue life depends mainly on the type of bituminous mixture, the type of geosynthetics, and the type and the amount of bitumen used for saturation and sticking. The amount of bitumen used to saturate and fix the geosynthetic signifi cantly changes the samples fatigue properties. Essential positive correlation between fatigue and parameters of interlayer bonding (shear strength, shear stiffness) occurs in both testing temperatures.

In this article, the issue of mining impact on road pavements and subgrade is presented, taking into account the interaction between geosynthetic reinforcement and unbound aggregate layers. Underground mining extraction causes continuous and discontinuous deformations of the pavement subgrade. Structural deformations in the form of ruts are associated with the compaction of granular layers under cyclic loading induced by heavy vehicles. Horizontal tensile strains cause the loosening of the subgrade and base layers. The granular layers under cyclic loading are additionally compacted and the depth of ruts increases. Moreover, tensile strains can cause discontinuous deformations that affect the pavement in the form of cracks and crevices. Discontinuous deformations also affect the pavement in the fault zones during the impact of mining extraction. The use of geosynthetic reinforcement enables the mitigation of the adverse effects of horizontal tensile strains. Horizontal compressive strains can cause surface wrinkling and bumps. Subsidence causes significant changes in the longitudinal and transverse inclination of road surface. Both examples of the laboratory test results of the impact of subgrade horizontal strains on reinforced aggregate layers and the selected example of the impact of mining deformation on road subgrade are presented in this article. The examples show the beneficial impact of the use of geosynthetic reinforcement to stabilize unbound aggregate layers in mining areas.

The paper presents the results of an extensive investigation of asphalt concrete specimens with geosynthetic interlayer. The subject of this research is evaluation of influence of geosynthetics interlayer applied to bituminous pavements on interlayer bonding of specimens. The results of the tests proves that when geosynthetic is used, the bonding of interlayer depends mainly on the type of bituminous mixture, the type of geosynthetic, and the type and amount of bitumen used for saturation and sticking of geosynthetic. The amount of bitumen used in order to saturate and fix the geosynthetic significantly changes the interlayer bonding of specimens.

The article presents a new approach to testing the strength of asphalt interlayer bonding. Two loading methods were used: static load and cyclic load. Before carrying out static shear strength tests, the interlayer bonding was subjected to cyclic loads with a constant number of cycles but with different frequencies. A number of layered samples with and without geosynthetic interlayers were tested at the set temperature. The comparative analyses allowed to determine the functions approximating the impact of the cyclic load frequency on the static strength of bonding at selected interlayer contact conditions. It was also possible to indicate the frequency of cyclic load at which this parameter has the largest and smallest impact on the static strength of the asphalt interlayer bonding.