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 .
The time of arrival of the P-wave at each transducer is determined as the point when the signal for each transducer rises above the background value.
Work Item s – proposed revisions of this atsm. Sorry, this content is unavailable because your browser does not support iframes. If the c13833 speed is determined by the surface measurement method, the resulting value is multiplied by 0. Your Alert Profile lists the documents that will be monitored.
It is the responsibility of the user of astn standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Subscription pricing is determined by: Besides thickness determination and flaw detection, the DOC can be used to estimate the depth of surface-opening cracks. There is a certain level of systematic error in the calculated thickness due to the discrete nature of the digital records that are used.
Furthermore, it is not possible cc1383 determine the depth to anomalies. No other units of measurement are included in this 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. The P-wave speed is calculated by dividing the distance between the two transducers by astmm travel time.
Click here for Agents. If test equipment is assembled by the user, thickness limitations shall be established and documented. The P-wave speed is ast by testing over a solid portion of a plate with known thickness. Powered by WordPress Theme Designed by: Lastly, the IE method will provide information on the depth of a flaw or defect, in addition to mapping its lateral location and extent.
A negative reflection coefficient means that the wstm changes sign when the stress wave is reflected; for example, a compressive stress would be reflected as a tensile stress.
Cracks Delaminations Honeycomb Thickness Voids. The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis. One method is by determining the thickness frequency and then measuring the actual plate thickness at that point.
Alternatively, Cp may be determined by measuring the time for the P-wave to travel between two transducers with a known separation. The P-wave generated by impact will reflect at interfaces within the concrete where there is c133 change in acoustic impedancewhich is defined as the product of the density and wave speed of a material. If the area of the reflecting interface is large, the impact-echo response will be similar to that of a solid plate except that the thickness frequency will be shifted to the higher value corresponding to the depth of d1383 interface.
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NDT System Add-On — Impact Echo
These notes and footnotes excluding those in tables and figures shall not c183 considered as requirements of the standard. If these conditions are not satisfied, the waveform will be of low amplitude and the amplitude spectrum will not include a dominant peak at the frequency corresponding to the thickness Eq 2.
Link to Active This link will always route to the current Active version of the standard. Please first verify your email before subscribing to alerts. 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.
The distance L mm between the transducers, is divided by time difference t between arrival of the P-wave at the second and first transducers. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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. Accurate measurement of thickness requires knowledge of the in-place P-wave speed.
IE investigations can also be performed to predict the strength of early age concrete if the member thickness is known.
The diffracted P-wave is detected by the transducer on the opposite side of the crack from the impact. The impact-echo method is based on monitoring the periodic arrival of reflected stress waves and is able to obtain information on the depth of the internal reflecting interface or the thickness of a solid member. The frequency of P-wave arrival is determined as the frequency with a high peak in the amplitude spectrum. c11383
The recorded waveform of surface displacement has a periodic pattern that is related to the thickness of the member and the wave speed. As the voice of the U. This standard is not included in any packages. This assumes that the P-wave speed is uniform with depth. Proceed to Checkout Continue Shopping. The figure below the waveform is the amplitude spectrum obtained by transforming the waveform into the frequency domain.
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.