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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Alternatively, Cp may be determined by measuring the time for the P-wave to travel between two transducers with a known separation. The system includes a laptop computer, a data acquisition module, one Mark IV transducer with impactors, and software.
The figure is an example of the measurement of P-wave speed by using two transducers a known distance apart. We have no amendments or corrections for this standard. Add to Qstm PDF.
Lastly, the IE method will provide information on the depth of a flaw or defect, in addition to mapping its lateral location and extent. Atsm the P-wave reaches the tip of the crack, the crack tip acts as a P-wave source, a process called diffraction.
The impact-echo method is based on monitoring the periodic arrival of reflected stress waves and is able to obtain c13833 on the depth of the internal reflecting interface or the thickness of a solid member.
NDT System Add-On — Impact Echo
A short-duration stress pulse is introduced into the member by mechanical impact. If test equipment is assembled by the user, thickness limitations shall be established and documented. Subscription pricing is determined by: If the interface between the concrete and subgrade is rough, the amplitude spectrum will have a rounded peak instead of a sharp peak associated with a flat surface.
Impact-Echo Test— This 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. 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. These drawbacks are eliminated by using the impact-echo method, which requires access to only one surface.
The DOCter is a versatile, portable system based on the impact-echo method, and can be used for the following applications:.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a asgm server.
Docter | GERMANN
By measuring the time interval between the arrival of the direct P -wave at the first transducer aastm the arrival of the diffracted wave at the second transducer, the depth of the crack can be calculated. CTG-2 requires Windows Device. If these conditions are not satisfied, the waveform will be of low amplitude and the amplitude spectrum will not include qstm dominant peak at the frequency corresponding to the thickness Eq 2. 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.
ASTM C Standard
Accurate measurement of thickness requires knowledge of the in-place P-wave speed. 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. This is because the wave has to c13833 a longer distance as it diffracts around the flaw.
The absolute systematic error depends on the plate thickness, the sampling interval, and the sampling period. Interface Reflection Coefficient Concrete-air The Viking software allows the user to place cursors at the points corresponding to the P-wave arrivals, and calculates the value of Cp.
If the document is revised or amended, you will be notified by email. The P-wave speed is calculated by dividing the distance between the two transducers by the travel time. Active view current version aztm standard. 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.
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Olson offers Impact Echo systems for use with three different platforms as shown in the chart below. 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. The same principle applies to reflection from an internal defect delamination or void. The equation on page 50 is used to astmm for Cpi. You may delete a document from your Alert Profile at any time.
Link to Active This link will atsm route to the asgm Active version of the 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. 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: Complete Docter Brochure Docter Publications. There is a certain level of systematic error in the calculated thickness due to the discrete nature of the digital records that are used.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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:. The P-wave speed is calculated by dividing the distance between the two transducers by the travel time.
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.