ASTM C1959_C1959M-26

1.1 This is a test method for measuring resonant frequencies of a concrete cylinder by recording the airborne sound emitted by the cylinder after being struck by an impactor. The sound is recorded through the microphone of a smartphone or tablet computer. The recorded sound signal is converted to the frequency domain, and the resonant frequency for a specific mode of vibration is determined from the amplitude spectrum. The measured resonant frequencies can be used to calculate the dynamic Young’s modulus of elasticity as described in Test Methods C215 or E1876.

1.2 References to smartphones or tablet computers in this test method do not preclude the use of other computing devices capable of performing the required data acquisition and processing functions.

1.3 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

1.4 The values stated in either SI units or inch-pound units are regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.