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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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. 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.
This makes the impact-echo method qstm powerful for detecting air interfaces, such as those due to delaminations, cavities, and honeycombed concrete. Subscription pricing is determined by: The Spider is placed adjacent to the Mark IV transducer as shown in the photo.
The thickness is calculated from this measured frequency and the P-wave speed obtained from Procedure A. Measurement of P-wave speed by surface method. Work Item s – proposed revisions of this standard.
The absolute systematic error depends on the asym thickness, the sampling interval, and the sampling period. The DOCter is a versatile, portable system based on the impact-echo method, and can be used for the following aetm. The peak at 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. The OE Website is loaded with Tech Brief and project photos using the equipment shown on this website.
You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server. This assumes that the P-wave speed is uniform with depth.
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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:. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
This assumes that the same P-wave speed is applicable at all test points. Depth of Surface-Opening 1c383 The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis. Sorry, this content is unavailable because your browser does not support iframes.
Detection of delaminations and honeycomb in sewer pipe. Proceed to Checkout Continue Shopping. Please first log in with a verified email before subscribing to alerts.
No other units of measurement are included in this standard. If the defect is just large enough to be detectable, the amplitude spectrum will show two peaks: 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. 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.
The P-wave speed is determined by testing over a solid portion of a plate with known thickness. The method is based on the assumption that the concrete plate has the same P-wave speed throughout its c13383.
These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard. Thus the correct equation for thickness calculation is: Interface Reflection Coefficient Concrete-air Measure the thickness of pavements, asphalt overlays, slabs-on-ground and walls Detect the presence and depth of voids and honeycombing Detect voids below slabs-on-ground Evaluate astk quality of grout injection in post-tensioning cable ducts Integrity of a membrane below an asphalt overlay protecting structural concrete Delamination surveys of bridge decks, piers, cooling towers and chimneystacks Detect debonding of overlays and patches Detect ASR damage and freezing-and-thawing damage Measure asttm depth of surface-opening cracks Estimate early-age strength development with proper correlation Principle A short-duration stress pulse is introduced into the member by mechanical impact.
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 asm apart along the surface of a structure.
These drawbacks are eliminated by using aztm impact-echo method, which requires access to only one surface. Already Subscribed to this document. Thus the P-wave undergoes multiple reflections between the two surfaces. One method is by determining the thickness frequency and then measuring the actual plate thickness at c13883 point. Training may be available at your location by one of our agents upon special arrangement. CTG-2 requires Windows Device.