ASTM D4830-98(R2021) pdf free download

ASTM D4830-98(R2021) pdf free download.Standard Test Methods for Characterizing Thermoplastic Fabrics Used in Roofing and Waterproofing
7. Puncture Strength
7.1 Scope: 7.1.1 This test method is used to measure the puncture strength of thermoplastic fabrics used in roofing. 7.1.2 This procedure is applicable to conditioned fabrics. 7.2 Summary ofMethod: 7.2.1 A specimen of the fabric is clamped without tension between grooved, circular plates of a ring clamp attachment secured in a tensile testing machine. A force is exerted against the center of the specimen by a solid steel rod attached to the load indicator until rupture occurs. 7.3 Significance and Use: 7.3.1 Puncture failures are recognized in the roofing indus- try. Puncture strength is felt to reflect the fabric’s ability to withstand aggregate or ballast stone penetration. This test method is used to obtain the relative puncture resistance of various fabrics. 7.4 Apparatus: 7.4.1 Tensile Testing Machine, of the constant-rate-of- extension type (CRE), with autographic recorder conforming to the requirements of Specification D76/D76M. 7.4.2 Ring Clamp Attachment, consisting of concentric grooved plates with an internal diameter of 44.45 6 0.025 mm [1.750 6 0.001 in.], capable of clamping fabrics without slippage. 7.4.3 Solid Steel Rod, with a hardness in the range of Rockwell C (HRC) 50 to 60, with a diameter of 7.938 6 0.013 mm [0.3125 6 0.0005 in.] and a hemispherical end with a radius of 3.970 6 0.013 mm [0.1563 6 0.0005 in.] for contacting the fabric surface (see Fig. 1). The surface of the hemispherical end should be smooth and polished to a surface smoothness of RMS ≤ 8. (RMS is the root-mean-square method of describing surface smoothness.) 7.5 Sampling, Number of Specimens, and Selection of Samples: 7.5.1 Lot Sample—As a lot sample for acceptance testing, take at random the number of rolls of fabric directed in an applicable material specification or other agreement between the purchaser and the supplier, such as agreement to sample as directed in Practice D4354. Consider rolls of fabric to be the primary sampling units. 7.5.2 Laboratory Sample—Take, for the laboratory sample, a sample extending the width of the fabric and approximately 1.0 m [39 in.] along with the selvage from each roll in the lot sample. The sample may be taken from the end portion ofa roll provided there is no evidence that it is distorted or different from other portions of the roll. In cases of dispute, take a sample that will exclude fabric from the outer wrap of the roll or the inner wrap around the core. 7.5.3 Unless otherwise agreed upon or specified in appli- cable material specifications, test a number of specimens from each laboratory sample that will give a precision of 65 % at a probability level of 90 %, not to exceed ten specimens per sample. 7.6 Preparation ofTest Specimen: 7.6.1 Each specimen shall be cut 76 by 76 mm [3.0 by 3.0 in.] to ensure proper clamping. Specimens should be taken on the diagonal across the sample so that no two specimens will contain the same machine direction and cross-machine direction yarns or fibers. Unless otherwise specified, no speci- men should be taken within 51 mm [2.0 in.] of the selvage or edge. 7.7 Conditioning: 7.7.1 Condition the specimens as directed in Practice D1776/D1776M. 7.8 Procedure: 7.8.1 All testing must be conducted at standard textile laboratory conditions as required in Practice D1776/D1776M. 7.8.2 Select the load range of the tensile testing machine such that the rupture occurs between 15 and 85 % of the full-scale load. 7.8.3 Center and secure the specimen between the grooved plates, ensuring that the fabric extends beyond the outer edges of the plates. 7.8.4 Measurement of Rupturing Load—Test at a machine speed of 5 mm/s or 12 in./min until the puncture rod com- pletely ruptures the specimen. Read the puncture strength as the greatest force in N [lbf] registered on the recording instrument during the test. 7.8.5 If the yarns or fibers fail to break due to the slippage ofthe specimen in the ring clamp or ifthe rod slips between the yarns or fibers without causing yarn or fiber breakage, discard the result and test another specimen. 7.9 Calculation: 7.9.1 Calculate the average of the rupturing load for all acceptable test results as read directly from the recording instrument.