AS 3706.2:2000 pdf free download – Geotextiles—Methods of test Method 2: Determination of tensile properties—Wide-strip method

AS 3706.2:2000 pdf free download – Geotextiles—Methods of test Method 2: Determination of tensile properties—Wide-strip method.
5 DEFINITIONS
For the purpose of this Standard. the definitions given in AS 3704 apply.
6 APPARATUS AND REAGENTS
The following apparatus and reagents are required:
a) Constant-rate-of-extension CRE tensile testing machine complying with the requirements for a Grade H machine in accordance with AS 2193. and having an cxtcnsion rate nI 20 mm mm.
The machine should have an autographic recorder with adequate pen response or an interfaced computer to properly record the force extension curse.
For machines with ,o autographic recorder, appropriate measuring instruments arc required to allow readings of the applied force and the corresponding extension at a number of points up to failure.
The jaws of the machine shall be not less than 10 mm wider than the width of the lest specimen and shall present the test specimen slipping. They shall also not damage the test specimen.
NOTES:
I Flat plate type jaws, often supplemented by small G-clamps placcd at X1 and X2. as shown in Figure I. have been found to hold most wide strip specimens satisfactorily.
2 Flat plate pncumalicJhysiraulic type jaws of appropriate site have also been found to he suitable.
(b) Area-measuring device, such as an integrating accessory to the tensile testing machine or a planimclcr.
(c) De-ionized waler and a non-ionic wetting agent.
(dl Water bath maintained at a temperature of 20 ±2°C.
7 PRF.PARATION OF TEST SPECIMENS
7.1 Sampling
A minimum of 10 tcst specimens shall be sampled in accordance with AS 3706.1.
The specimens shall be cut as follows:
(a) A minimum of live specimens with the larger dimension in the machine direction.
b) A minimum of five specimens with the larger dimension in the cross-machine direction.
7.2 SIte of specimens
7.2.1 For cirmu.sphericullv conditiont’d letting
Each specimen shall be prepared so that it ix 200 mm wide (excluding ravelled edge when applicable). The length of the specimen depends on the type of jaw being used. For all jaw types the length shall be such that the ends of the specimen shall project not less than 20 mm beyond the jaws.
For woven geotextiles the 2(X) turn width of the test specimen shall be obtained by cutting the specimen 220 mm wide and removing or ravelling threads from each side alternately until the removal of one more thread will reduce the width below 2(10 mm. The width of the cut test specimen shall be obtained by cutting in the machine or cross-machine direction, as appropriate.
10.2 kepresentatise saints
From the values determined for individual specimens, representative values shall he determined for the following properties:
(a) Yield tensile strength (to the nearest 0.1 LN) and elongation at yield Force (to the nearest I percent).
(I’) Ultimate tensile strength (to the nearest 0.1 kN) and elongation at ultimate force (to the nearest 1 percent).
(e) Offset modulus and offset elongation.
(d) Other properties as required.
For each propeny. the following representative values shall be determined (see
AS 3706.1):
(i) Mean value.
(ii) Standard deviation.
(iii) Coefficient of variation.
(iv) Fifth percentile value for all required tensile strength measures, for all moduli measurements, and for the toughness.
(4) Ninety-fifth percentile value for all required elongation measures.
NOTE: l’he representative value of characteristic elongation should he designated ‘representative characteristic elongation’, to distinguish it from thai obtained from single speciinens
The results that were rejected in accordance with Clause 9(d) and (f) shall not be included in the calculations: however, the rejected results shall be recorded and reported separately.