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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Asym the document is revised or amended, you will be notified by email. In impact-echo testing, the P-wave is used to obtain information about the member. The thickness is calculated from this measured frequency and the P-wave speed obtained from Procedure A. 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. Link to Active This link will always route to the current Active version of the standard.
Click atm for Agents. This assumes that the P-wave speed is uniform with depth. This assumes that the same P-wave speed is applicable at all test points.
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 figure below the waveform is the amplitude spectrum obtained by transforming the waveform into the frequency domain. If the wave speed is determined zstm the surface measurement method, the resulting value is multiplied by 0.
ASTM C1383 – 15
You may delete a document from your Alert Profile at any time. Measurement of P-wave speed by surface method. 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.
Interface Reflection Coefficient Concrete-air Already Subscribed to this document.
The frequency shift is a good indicator of the presence of a flaw if it is known that the plate thickness is constant. A short-duration stress pulse is introduced into the member by mechanical impact. Testing for quality of grout injection in cable ducts located by ground penetrating radar. 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.
Furthermore, it is not possible to determine the depth to anomalies. Cracks Delaminations Honeycomb Thickness Voids. Your Alert Profile lists the documents that will be atm.
No other units of measurement are included in this standard. CTG-2 requires Windows Device.
Docter | GERMANN
Complete Docter Brochure Docter Publications. Thus the P-wave undergoes multiple reflections between the two surfaces. The Spider multiple impactor unit can be purchased as an option to increase the operating range of the systems.
A sensitive displacement transducer next to the impact point picks up the disturbance due to the arrival of the P-wave. Need more than one copy? It is available on a consulting basis through our sister company, Olson Engineering. This is because the wave has to travel a longer distance as it diffracts around the flaw. Astmm limits shall be specified by manufacturer of the apparatus, and the apparatus shall not be used beyond these limits.
The figure is an example of the measurement of P-wave speed by using two transducers a known distance apart. F1383 frequency content covered by the Spider impactors is approximately 1.
The frequency of P-wave arrival is determined as the frequency with a high peak in the amplitude spectrum. As explained in Note 12the minimum lateral dimensions and acceptable sampling period are related. 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 ashm 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. The peak at 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.
You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server. The displacement waveform is transformed into the frequency domain to produce an amplitude spectrumwhich shows the predominant frequencies in the waveform.
IE investigations can also be performed to predict the strength of early age concrete if the member thickness is known. Asfm test equipment is assembled by the user, thickness limitations shall be established and documented.
These minimum lateral dimensions are necessary to prevent other modes 3 of vibration from interfering with the identification of the thickness mode frequency in the amplitude spectrum.