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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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 makes the impact-echo method inherently powerful for detecting air interfaces, such as those due to delaminations, cavities, and honeycombed concrete. Proceed to Checkout Continue Shopping.
This standard is not included in any packages. The diffracted P-wave is detected by the transducer on the opposite side of the crack from the impact.
It is seen that at a concrete-air interface, there is complete reflection of the P-wave. Link to Active This link will always route to the current Active version of the standard.
Subscription pricing is determined by: Sorry, this content is unavailable because your browser does not support iframes. Powered by WordPress Theme Designed by: 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 satm in sewer pipe.
This assumes that the same P-wave speed is applicable at all test points. IE investigations can also be performed to predict the strength of early age concrete if the member thickness is known.
Please first verify your email before subscribing to alerts. 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. 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.
Historical Version s – view previous versions of standard. This assumes that the P-wave speed is uniform with depth. A short-duration stress pulse is introduced into the member by mechanical impact. Impact Echo IE investigations are performed to assess the condition or thickness of slabs, beams, columns, walls, pavements, runways, tunnels, and dams.
Lastly, the IE method will provide information on the depth of a flaw or defect, in addition to mapping its lateral location and extent. 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 distance L mm between the transducers, is divided by time difference t between arrival of the P-wave at the second and first transducers.
Complete Docter Brochure Docter Publications. The P-wave speed is aetm by dividing the distance between the two transducers by asttm travel time.
NDT System Add-On — Impact Echo
The figure is an example of the measurement of P-wave speed by using two transducers a known distance apart. The DOCter is a versatile, portable system based on the impact-echo method, and can be asym for the following applications:.
Besides thickness determination and flaw detection, the DOC can be used to estimate the depth of surface-opening cracks. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
The P-wave is then reflected back into the member and the cycle begins again. We have no amendments or corrections for this standard. As the voice of the U. 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:.
ASTM C Standard
This is because the wave has to travel a longer distance as it diffracts around the flaw. Example The upper plot in this example shows the surface displacement waveform obtained from a test of a solid concrete slab. Accurate measurement of thickness requires knowledge of the in-place P-wave speed.