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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Training may be available at your location by one of our agents upon special arrangement. 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. 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.
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.
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.
Testing for quality of grout injection in cable ducts located by ground penetrating radar. 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.
Link to Active This link will always route to the current Active version of the standard. The frequency content covered by the Spider impactors is approximately 1. Furthermore, it is not possible to determine the depth to anomalies. Historical Version s – view previous versions of standard. The method is based on the assumption that the concrete plate has the same P-wave speed throughout its depth.
By measuring the time interval between the arrival of the direct P -wave at the first transducer and the arrival of the diffracted wave at the second transducer, the depth of the crack can be calculated.
The frequency of P-wave arrival is determined as the frequency with a high peak in the amplitude spectrum.
The LONGSHIP transducers are placed on opposite sides of the crack as shown in the sketch to the right and impact is generated on the line passing through the transducers. Measurement of P-wave speed by surface method. The P-wave speed is calculated by dividing the distance between the two transducers by the travel time.
Docter | GERMANN
The frequency shift is a good indicator of the presence of a flaw if it is known that the plate thickness is constant. If test equipment is assembled by the user, thickness limitations shall be established and documented. The absolute systematic error depends on the plate thickness, the sampling interval, and the sampling period. 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.
If the wave speed is determined by the surface measurement method, the resulting value is multiplied by 0. No other units of measurement are included in this standard. Work Item s – proposed revisions of this standard. As explained in Note 12the minimum lateral dimensions and acceptable sampling period are related.
This impact generated three types of stress waves that propagate away from the impact point. Your Alert Profile lists the documents that will be monitored. A negative reflection coefficient means that the stress changes sign when the stress wave is reflected; for example, a compressive stress would be reflected as a tensile stress. Detection of delaminations and honeycomb in sewer pipe. Click here for Agents.
These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard. 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.
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.
Standards Subscriptions from ANSI provides a money-saving, multi-user asfm for accessing standards. Aatm following lists the reflection coefficients of a P-wave travelling through concrete and incident normal to an interface with air, water, soil, or steel: It is available on a consulting basis through our sister company, Olson Engineering. The recorded waveform aastm 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. P-Wave Speed Measurement— This 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.
A sensitive displacement transducer next to the impact point picks up the disturbance due to the arrival of the P-wave. One method is by determining the thickness frequency and then measuring the actual plate thickness at that point. DOCter Purpose The use of traditional stress wave methods, atm as ultrasonic through transmission, to identify the presence of anomalies in structures requires access to both faces of a member.
NDT System Add-On — Impact Echo
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 figure is an example of the measurement of P-wave speed by using two transducers a known distance apart.
The distance L mm between the transducers, is divided by time difference asmt between arrival of the P-wave at the second and first transducers. The DOCter is a versatile, portable system based on the impact-echo method, and can be used for the following applications:.
ASTM C1383 – 15
These drawbacks are eliminated by using the impact-echo method, which requires access to only one surface. Olson offers Impact Echo systems for use with three different platforms as shown in the chart below. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard. If these conditions are not satisfied, the waveform will be of low amplitude and the astmm spectrum will not include a dominant peak at the frequency corresponding to the thickness Eq 2.
Accurate measurement of thickness requires knowledge of the in-place P-wave speed. Thus the correct equation for thickness calculation is: Standards Subsctiption may be the perfect solution.
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With the LONGSHIP two-transducer assembly, the transducers are c1338 mm apart and the impactor is about mm from one of the transducers one the line passing through the transducers.