Geogrids are building materials widely used for soil reinforcement that can be affected by the action of many degradation agents throughout their service life. The potential negative effect of the degradation agents should be properly estimated and accounted for during the design phase. The main aim of this work was to study the influence of mechanical damage under repeated loading on the resistance of geogrids against abrasion. Three geogrids (one extruded and two woven) were exposed in isolation to mechanical damage under repeated loading and abrasion tests, followed by the successive exposure to both degradation tests. The damage suffered by the geogrids was evaluated by visual inspection and by tensile tests. Based on the changes found in tensile strength, reduction factors were determined. The reduction factors obtained directly from the successive exposure were compared to those resulting from a method in which the reduction factors obtained for the isolated effect of each degradation agent were multiplied. Results indicated that the abrasion process tended to be affected by a previous exposure to mechanical damage under repeated loading and that the multiplication of the reduction factors obtained for the isolated effects of the degradation agents may not correctly represent their combined effect.
Keywords: abrasion; degradation agents; geogrids; geosynthetics; mechanical damage; reduction factors; tensile behaviour.