1.1 This test method covers the measurement, on a laboratory scale, of the contribution of asbestos fibers to the strength of asbestos-cement products. The results obtained are used in the primary assessment of different fiber grades prior to their application on a larger scale.

1.2 This test method covers the determination of the modulus of rupture (MR), adjusted to a dry density of 1.60 Mg/m³ (MR _A), of asbestos-cement test specimens that contain the asbestos fiber to be evaluated at a concentration of 10 mass %, whereby the degree of fiberization of that fiber is specified in terms of specific surface area as determined by Test Method D 2752. The relative reinforcing value of the fiber under test is established by comparison with MR_A values obtained with a fiber of known characteristics at a fiber concentration of 10 % and a dry density of 1.60 Mg/m³ (1.60 g/cm³).

Note—The adjusted modulus of rupture (MR_A) at any intermediate fiber concentration may be interpolated from results suitably determined over a limited spanning range of fiber concentrations. For example, the MR_A at 10 % fiber concentration may be graphically determined from data at 3 and 17 %.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.