PROTECTION EFFICIENCY OF NONWOVEN POLYPROPYLENE GEOTEXTILES AGAINST IMPACT DAMAGE

摘要

European Standard EN ISO 13428:2005 specifies an index test to determine the protection efficiency offered by a geotextile against the impact load of a hemispherical object. Laboratory tests were conducted on 70 nonwoven polypropylene geotextiles (needle-punched, heat-boned, post-treated) made of staple fibers or continuous filament, with mass per unit area 113-2217 g/m2 and thickness 0.50-1.88 mm. The effect of impact energy and of a deformable pad instead of the rigid support was evaluated. The protection efficiency of the geotextiles, as represented by the percent residual thickness of the lead plates in the impact areas, ranged between 17.3% and 89.2%. An excellent linear correlation (R2=0.95) was obtained between residual thickness and geotextile mass per unit area. Use of a deformable support improved the measured protection efficiency by 5%-400% depending on geotextile mass. Half of the standard impact energy resulted in protection efficiency improvement by 10%-- 150% depending on geotextile mass.When the standard impact energy was doubled, geotextiles with mass up to 800 g/m2 provided no protection.