Practice and Research of Geosynthetic Reinforced Soil Walls in Australia - Reinforced Soil Engineering: Advances in Research and Practice - page 254

from sandy silt to silty sand, was used in this study. The test results
unambiguously suggested that fly ash can be used as a select fill material.

4.1.2 Pullout Resistance of Polyester Straps

Significant efforts have been made in studying the pullout resistance of high-
tenacity polyester straps for the Freyssisol (formerly known as Websol) GRS wall
system. A typical cross section of the polyester strap, formerly known as
Paraweb, is shown in Fig. 4.
It is available in five different grades, but the overall dimensions of the
straps are approximately the same for all five grades. Due to the high load-
carrying capacity of the strap and its relatively small perimeter, the pullout
resistance often controls the reinforcement length at low overburden stress.
A large-scale pullout apparatus that utilizes a flexible sleeve near the front wall
was used in this study. The pullout resistance as measured on a pullout box can be
expressed as

R p ¼ aFs 0 pL p ð 2 Þ

where a is a scale correction factor, F is the basic parameter characterizing
interface strength, s 0 is the applied pressure, p is the perimeter, and L p is

Figure 4 Cross section of Paraweb.