This standard is issued under the fixed designation C ; the number 1 This test method is under the jurisdiction of ASTM Committee C-9 on Concrete. Purchase your copy of ASTM C – 15 as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards available. mm. Thickness Measurement by ASTM C Accurate measurement of thickness requires knowledge of the in-place P- wave speed. ASTM C, “Test .
|Published (Last):||8 February 2017|
|PDF File Size:||2.81 Mb|
|ePub File Size:||3.9 Mb|
|Price:||Free* [*Free Regsitration Required]|
Measurement of P-wave Speed The figure is an example of the measurement of P-wave speed by using two transducers a known distance apart. When the P-wave reaches the tip of the crack, the crack tip acts as a P-wave source, a process called diffraction.
P-Wave Speed MeasurementThis procedure measures the time it takes for the P-wave generated by a short-duration, point impact to travel between two transducers positioned a known distance apart along the surface of a structure. Already Subscribed to this document. These drawbacks are eliminated sstm using the impact-echo method, which requires access to only one surface.
Standards Subscriptions from ANSI provides a money-saving, multi-user solution for accessing standards.
ASTM C1383 – 15
A negative reflection coefficient means that the stress changes c3183 when the stress wave is reflected; for asmt, a compressive stress would be reflected as a tensile stress. The figure below the waveform is the amplitude spectrum obtained by transforming the waveform into the frequency domain. This assumes that the same P-wave speed is applicable at all test points. Training may be available at your location by one of our agents upon special arrangement.
Contact Olson Instruments when adding on to an existing system, or purchasing multiple systems as some of the components are common to other test methods. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard. The P-wave generated by impact will reflect at interfaces within the concrete where there is a change in acoustic impedancewhich is defined as the product of the density and wave speed of a material.
There is a certain level of systematic error in the calculated thickness due to the discrete nature of the digital records that are used. Thus the P-wave undergoes multiple reflections between the two surfaces. Please first log in with a verified email before subscribing to alerts. It is seen that at a concrete-air interface, there is complete reflection of the P-wave. The P-wave speed is calculated by dividing the distance between the two transducers by the travel time.
DOCter Purpose The use of traditional stress wave methods, such as ultrasonic through transmission, to identify the presence of anomalies in structures requires access to both faces of a member. The recorded waveform of surface displacement has a satm pattern that is related to the thickness of the member and the wave speed.
This standard is not included in any packages. As the voice of the U. If test equipment is assembled by the user, thickness limitations shall be established and documented. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard.
Referenced Documents purchase separately The documents listed c11383 are referenced within the subject standard but are not provided as part of the standard. 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. Furthermore, it is not possible to determine the depth to anomalies.
Docter | GERMANN
The following lists the reflection coefficients of a P-wave travelling through concrete and incident normal to an interface with air, water, soil, or steel:. All of Olson Instruments have been researched, tested, and used on-site daily by our sister company, Olson Engineeringworld reknowned for NDT consulting.
The Spider is placed adjacent to the Mark IV transducer as shown in the photo. Impact-Echo TestThis procedure measures the frequency at which the P-wave generated by a short-duration, point impact is reflected between the parallel opposite surfaces of a plate.
Depth of Surface-Opening Cracks The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis. Link c13883 Active This link will always route to the current Xstm version of the standard.
Thus the correct equation for thickness calculation is: Interface Reflection Coefficient Concrete-air If the document is revised or amended, you will be notified by email.
The method is based on the assumption that the concrete plate has the same P-wave speed throughout its depth. Subscription pricing aztm determined by: The same principle applies to reflection from an internal defect delamination or void.
No other units of measurement are included in this standard. Add to Alert PDF.
Link to Active This link will always atm to the current Active version of the standard. When the P-wave reaches the back side of the member, it is reflected and travels back to the surface where the impact was generated. Your Alert Profile lists the documents that will be monitored. The thickness is calculated from this measured frequency and the P-wave speed obtained from Procedure A. The frequency of P-wave arrival is determined as the frequency with a high peak in the amplitude spectrum.
The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis.