Investigation of the Parameters Affecting on the long-Term Creep Behavior of the Woven and Nonwoven Geotextile Polyester Fabrics

Investigation of mechanical properties in general and long-term creep behavior of the geotextile fabrics in particular, has a considerable importance due to the relevant conventional applications. In this research, in addition to design of a laboratory creep tester apparatus, effect of the various variables on the creep behavior of the woven and needle-punched nonwoven geotextile polyester fabrics was studied. The obtained results for the woven geotextile fabrics showed that more weft density causes to increase creep value; although, higher magnitude of the weft density can reduce rate of creep enhancement due to less movement ability between weft and warp yarns. The secondary creep characteristic for the different studied weft yarn structures is also evaluated at the same level. The results of the nonwoven geotextile fabrics demonstrated that increasing all parameters of needle penetration depth, areal weight and punch density leads to a reduction in the amount of creep. It should be noted that the amount of creep strain in the nonwoven geotextile fabrics were much higher than that of woven geotextile fabrics. It was also concluded that the magnitude of the creep strain for the both studied geotextile fabrics initially reaches to the maximum value and then meets a nearly regular behavior. This phenomenon happens for the nonwoven geotextile fabrics in the less time than what it is necessary for the woven geotextile fabrics. In the other word, the studied nonwoven geotextile fabrics show more stable creep behavior in the long-term condition.