APPENDIX A: GEOTEXTILE SURVIVABILITY REQUIREMENTS

APPENDIX A: GEOTEXTILE SURVIVABILITY REQUIREMENTS

This appendix is provided as a convenience to readers, so that geotextiles meet-

ing survivability requirements may be specified for acquisition without referring

to TM5-818-8 (1995). It can be used in place of Tables 2-2, 2-3, and 2-4 in U.S. Army

TM5-818-8. The guidance provided here is taken from AASHTO-AGC-ARTBA Joint

Committee: Subcommittee on New Highway Materials, Task Force 25 (1990) and is

more recent guidance than that provided in TM5-818-8.

Table A-1. Construction survivability ratings.

Site soil CBR

<1

1 to 2

>3

Equipment ground contact

>350(50) <350(50)

pressure, kPa (psi)

Cover thickness, compacted

(mm/in.)a

100/4b,c

NR

H

M

150/6

NR

H

M

300/12

NR

H

M

450/18

H

M

aMaximum

aggregate size not to exceed one half of compacted cover thickness.

bFor

low-volume, unpaved roads (average daily traffic less than 200 vehicles).

cMinimum cover thickness is limited to existing road bases and is not intended for use in new construc-

tion.

H = high, M = medium, NR = not recommended.

Table A-2. Geotextile physical property requirements for

survivabilitya

<50% elongation/>50% elongationb,c

Grab

Puncture

Trapezoidal

Required

strength

resistance

tear strength

survivability

(kN/lb)

level

ASTM D 4632

ASTM D 4833

ASTM D 4533

H

270/180

100/75

M

180/115

70/40

Additional requirements

Test method

Apparent opening size

ASTM D 4751

1. <50% soil finer than 0.075 mm, AOS <0.6 mm

2. >50% soil finer than 0.075 mm, AOS > 0.3 mm

Permeability

ASTM D 4491

Kgeotextile > Ksoil

Kgeotextile = permittivity nominal geotextile thickness

Ultraviolet degradation

ASTM D 4355

At 150 hr exposure, 70% of strength retained for

all cases

Geotextile acceptance

ASTM D 4759

aValues

shown are minimum roll average values.

bElongation

as determined by ASTM D 4632.

cValues of geotextile elongation do not imply the allowable consolidation

properties of the subgrade soil. These must be determined by a separate

investigation.

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