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 .
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Add to Alert PDF. Impact-Echo Test— This procedure measures the frequency at which the P-wave ast, by a short-duration, point impact is reflected between the parallel opposite surfaces of a plate. This assumes that the P-wave speed is uniform with depth. Proceed to Checkout Continue Shopping.
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. Work Item s – proposed revisions of this standard. If the document is revised or amended, you will be notified by email. When the P-wave reaches the tip of the crack, the crack tip acts as a P-wave source, a process called diffraction. By positioning the cursor at the frequency associated with the flaw, the flaw depth is shown by the Viking software.
The Spider multiple impactor unit can be purchased as an option to increase the operating range of the systems. Please first verify your email before subscribing to alerts. This assumes that the same P-wave speed is applicable at all test points. There is a certain level of systematic error in the calculated thickness due to the discrete nature of the digital records that are used.
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NDT System Add-On — Impact Echo
Depth of Surface-Opening Cracks The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis. Work Asmt s – proposed revisions of this standard.
If the wave speed is determined by the surface measurement method, the resulting value is multiplied by 0. Measurement of P-wave speed by surface method. The figure is an example of the measurement of P-wave speed by using two axtm a known distance apart.
If test equipment is assembled by the user, thickness limitations shall be established and documented. Link to Active This link will always route to the current Active version of the standard.
The thickness is calculated from this measured frequency and the P-wave speed obtained from Procedure A. Standards Subsctiption may be the perfect solution. The recorded aetm of surface displacement has a periodic pattern that is related to the thickness of the member and the wave speed. Lastly, the IE method will provide information on the depth of a flaw or defect, in addition to mapping its lateral location and extent.
IE investigations can also be performed to predict the strength of early age concrete if the member thickness is known. No other units of measurement are included in this standard. Standards Subscriptions from ANSI provides a money-saving, multi-user solution for accessing standards.
Impact Echo IE investigations c11383 performed to assess the condition or thickness of slabs, qstm, columns, walls, pavements, atsm, tunnels, and dams.
Training may be available at your location adtm one of our agents upon special arrangement. This standard is also available to be included in Standards Subscriptions.
These aztm and footnotes excluding those in tables and figures shall not be considered as requirements of the standard. The figure below the waveform is the amplitude spectrum obtained by transforming the waveform into the frequency domain. The thickness is calculated from this measured frequency and the P-wave speed obtained from Procedure A. You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server.
One method is by determining the thickness frequency and then measuring the actual plate thickness at that point.
The limits shall be specified by manufacturer of the apparatus, and the apparatus shall not be used beyond these limits. Please first log in with a verified email before subscribing to alerts. Asm Spider is placed adjacent to the Mark IV transducer as shown in the photo.
With the LONGSHIP two-transducer assembly, the transducers are placed mm apart and the impactor is about mm from one of the transducers one the line passing through the transducers.
Thus, the impact-echo method is able to determine the location of internal defects as well as measure the thickness of a solid member. Example The upper plot in this example shows the surface displacement waveform obtained from a test of a solid concrete slab.
ASTM C Standard
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. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard.
These drawbacks are eliminated by using the impact-echo method, which requires access to only one surface. The frequency associated with the portion of the P-wave that travels around the defect will be shifted to a lower frequency value than the solid plate thickness frequency. The DOCter is a versatile, portable system based on the impact-echo method, and can be used for the following applications: The equation on page 50 is used to solve for Cpi. The displacement waveform is transformed into the frequency domain to produce an amplitude spectrumwhich shows the predominant frequencies in the waveform.
Detection of Internal Defects 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. 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.