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11/15/1995 07:32 6045304466 DEC_K._ING PAGE 10 <br /> After weathering, remove the specimens from the apparatus. Examine visually for signs of cracking, blistering for <br /> appreciable colour change,and then carry out the tests for elongation, low temperature impact,and loan temperature <br /> flexibility with the modifications as described earlier in this paragraph. <br /> 7.3.10 Water Vapour Transmission --- Perfort>s in accordance with ASTM E 96. Procedure A. for Classes A and B <br /> membranes, and in accordance with ASTM B 96, Procedure 13W, for Class C membranes. <br /> 7.3.11 Water Absorption — Cary out the test as described for sheets in ASTM D 570, except the samples shall <br /> immersed in water at 70 t 1°C for 7 d. Cut specimens of sufficient size and number to perforin the tests described in <br /> ASTM D 570 and par.7.3.3 and 7.3.4. For membranes with a fabric backing, the backing shall be removed, prior to <br /> immersion. on specimens for determining change in mass; the backing shall be left intact on specimens for <br /> determining retention of strength and elongation. For Type 4 membranes, cut edges that expose the minforcernent <br /> shall be sealed using a hot air gun operated at the manufacturer's recommended temperature, before immersing in <br /> water. Weigh the specimen before and after immersion and calculate the gain in mass as a percent of the int "al <br /> mass. Carry out tensile or breaking strength and elongation tests in accordance with par. 7.3.3 and 7.3.4. Comp7 <br /> the results with the tests carried out on material as received. <br /> 7.3.12 Dimensional Changs Afar Stress Relaxation (Without Loading) –•-Cut five strips of membrane 25 x 250 mm n <br /> the machine direction and cut five strips in the cross machine direction, indicating this information on the strips. <br /> Measure the lengths of these cut strips precisely using s travelling stage microscope. Place the strips horizontally on <br /> a flat smooth surface in an air-circulating oven at 801 1°C for 6 h. Remove the strips from the oven and allowo <br /> condition for 5 h. Measure the lengths of the strips precisely, using the travelling stage microscope and determine <br /> the dimensional change (shrinkage or expansion) for both the machine and cross machine directions, <br /> 7.3.13 Dimensional Change After Stress Relaxation (Wilk Loading) — Cut a 300 x 300 mm specimen of membrane <br /> which has the machine direction marked. Mark out a 250 x 250 stun square accurately in the centre of the aacnple <br /> piece. Precisely measure both the machine and cross machine direction distant a in the 250 x 250 mm square using <br /> a travelling stage microscope. place the sample sheet on a smooth flat sheet of 4.5 mm thick asbestos-cement bout. <br /> Place a 250 x 250 mm sheet of 4.5 mm thick asbestos-cement board exactly over the square sheet of membrane. <br /> Place a 250 x 250 x 50 rnm concrete patio slab exactly over the asbestos-cement boats. Place the weighted sample, <br /> mounted as described aboveth, in an air-circulating oven at 80 t VC for 6 h. Remove from the oven and allow to <br /> condition for 5 h. Remove the patio slab and asbestos board from the sample and treasure the change in dimcnsi n <br /> of the sample membrane in both the machine and cross machine diredtions using a travelling stage microscope <br /> 7.3.14 Cone Penetration—Cut five 50 x 50 mm specimens of membrane. Fit a stainless steel 60°Gone penetration needle <br /> onto the crosshead of a tensile testing machine.The tip of the cone shall be rounded having a radius of curvature <br /> 0.5 min. Use a 75 x 75 x 6 min section of aluminum as the base substrate.The aluminum plate shall be connected <br /> electrically so that when the steel cone penetrates the specimen and touches the aluminum base plate, the machine s <br /> turned off and the force required to puncture the specirden is recorded. Perform five tests at a croashead speed f <br /> 1.27 mrnlmin and report the average force required to puncture the membrane. <br /> 7.3.15 Asphalt eompadbility -- Cut three specimens, 75 mm x 75 mm x the membrane thickness. Condition overnight $t <br /> standard conditions and then weigh each to the nearest 0.1 mg. lt=erse the specimens in n-hexane at 23 t 2°C i <br /> separate, 500 mL, screw-capped jars. After 2 h, remove the specimens from the jars, blot dry with cheesecloth ( <br /> other lint-free,absorbent cloth)and place in a property vented,air circulating oven at 9012°C for 45 minutes. Aft r <br /> this time, remove from the oven, condition at standard conditions overnight and then aweigh, Calculate <br /> percentage weight loss for the three specimens to the nearest 0.1% and report the average (Nott 5). <br /> 8. NOTES <br /> 8.1 Options -- The following options must be specified in the application of this standard: <br /> a. Type and class (par. 3.l) <br /> b. Packaging and packing details, if other than specified (par.6.1) <br /> c. Labelling requirements, if other than specified (par.6.2) <br /> Note S.It is hot necessary to rake precautiow to avoid contact between exposed fibres and he.rarfe.Arry hecam nose is abs, <br /> L.. !L_-. ..,:1r L. -1-4-4 4 A—ion d, --M drW <br />