EuroGeo4 Paper number 203 1 ANALYSIS OF MECHANICAL AND PHYSICAL PROPERTIES ON GEOTEXTILES AFTER WEATHERING EXPOSURE Paulo César Lodi 1 , Benedito De Souza Bueno 2 , Jorge Gabriel Zornberg 3 & Natália De Souza Correia 4 1 São Paulo State University (UNESP) at Ilha Solteira. (e-mail: plodi@dec.feis.unesp.br) 2 University of State of São Paulo (USP) at São Carlos. (e-mail: bsbueno@sc.usp.br) 3 University of Texas at Austin. (e-mail: zornberg@mail.utexas.edu) 4 University of State of São Paulo (USP) at São Carlos. (e-mail: nataliacorreia@uol.com.br) Abstract: When geotextiles are exposed to solar rays for a short or long period of time, some level of UV degradation occurs. In this sense, variations in physical and mechanical properties may occur due to degradation by outdoor exposure. This paper presents results of mechanical and physical properties on 3 polyester PET non-woven geotextiles that were exposed to weathering for 720 and 1440 hours (1 and 2 months). Properties were evaluated according to the Brazilian standards (NBR). The results showed that the geotextiles presented some variations in tensile properties after exposure. Deformability decreases after all times of exposure. The samples became stiffer than fresh samples. Keywords: geotextile, weathering, laboratory tests. INTRODUCTION Geotextiles (GT) may be exposed to UV radiation in many different ways. The time of exposure may cause some level of degradation on the materials since all the geosynthetics contain polymers in their formulation. All the geotextiles are sensitive to UV effects. Loss of properties (tensile resistance and deformability, for example) may occur in prolonged exposure. Generally, the polyester (PET) shows medium to good UV resistance. Thus, evaluation of the effects of outdoor exposure is very important. The ASTM D5970 procedure is commonly used as a guide to evaluate geotextile products for outdoor exposure. Because, in outdoor testing, the effects of sunlight can take an extended period of time to become apparent, an accelerated method is desirable. Many methods of accelerated weathering of geotextiles are available (Baker 1997). This paper presents results of mechanical and physical properties of 3 PET non-woven geotextiles (171, 280 and 450 g/m 2 ) that were exposed to weathering for 1 and 2 months. Properties were evaluated according to the Brazilian standards (NBR). MATERIAL AND METHODS Non-woven geotextiles (GT) were exposed according to ASTM D1435 and D5970. Samples were placed on a panel located in the east-west axis angled towards the sun (Figure 1). Three Polyester (PET) non-woven geotextiles were exposed and evaluated: 171, 280 and 450 (g/m 2 ). These will be referred to as PET 171, PET 280 and PET 450. The PET geotextiles were exposed for a total period of 2 months. Physical and tensile properties were evaluated and compared to intact (un-exposed) material. Tests were carried out in accordance with ABNT standards (Brazil standards): ABNT NBR 12568 (mass per unit area) and ABNT NBR 12824 (tensile properties). Figure 1. PET non-woven geotextile samples exposed to weathering