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Damage assessment in concrete using quantitative acoustic emission
- N D T abstracts NDT Abstracts is a current awareness service compiled by the National NDT Centre, Harwell Laboratory, Didcot, Oxon, OXll 0RA, UK. The entries are drawn from over 500 British and International publications. Each issue concentrates on one or two subject areas. The subjects covered in previous issues from February 1990 onwards are: Acoustic microscopy - February 1990; Concrete - April 1990; Eddy currents - December 1990; G a m m a tomography June 1991; Image processing - June 1990; Magneto-acoustic emission and the Barkhausen effect - February 1991; Radiographic inspection of welds - August 1991; Ultrasonic testing of composites - August 1990; Vibration testing April 1991; X-ray t o m o g r a p h y - October 1990
Ultrasonic and acoustic testing of concrete 48559
Muravin, G.B.; Merman, A.L; Lezvinskaya, L.M.
Acoustic-emission method for estimating the fracture toughness of concrete in large-scale structures and buildings Soviet Journal o f Nondestructive Testing, Vol. 27, No. 3, pp. 166-171 (Nov. 1991) An acoustic-emission technique is developed for estimating the fracture toughness of materials in structures by the calibrated impact method. It is shown that the criteria K l c and J t c can be refined on the basis of data from measurements of the emission parameters. It is established that the reliability of determination of the toughness criteria of heterogeneous materials can be increased up to 30% by acoustic-emission measurements performed with longitudinal mode transducers. 48310
Ouyang, C.; Landis, E.; Shah, S.P.
Damage assessment in concrete using quantitative acoustic emission Journal o f E n g i n e e r i n g M e c h a n i c s , Vol. 117, No. 11, pp. 2 6 8 1 - 2 6 9 8 (Nov. 1991) Quantitative AE techniques were applied to a laboratory study of plain concrete beams under four point loading. Center-notched and off- center-notched beams were loaded in order to produce, respectively, mode I and mixed mode failure. Using AE seismic moment tensor representation, microcracking was characterized as mode I, mode II, or mixed mode. The mode of microcracking was compared to the mode of the visible crack. Most microcrack planes were in a direction normal to the tensile stress for a mode I macrocrack (center-notched), whereas microcrack planes were relatively uniformly distributed for a mixed- mode macrocrack (off-center notched). A large number of mixed-mode microcracks were observed even for the center-notched beam indicating that fracture mechanisms of microcracks may differ from the main macromechanical crack. It is shown that AE measurements can provide a potentially powerful tool in assessing damage. 48286
Chevron Research and Technology Company; (Rutledge, J.M.)
Method for cement evaluation using acoustical l o g s U.S. Patent No. 5 , 0 3 6 , 4 9 6 (30 Jul. 1991) The quality of element material in the annular spaces behind casings or in wellbore liners can be measured using the method described here which produces an evaluation using acoustical log keeping. A sonic test cell is used to determine the transit time of a sound wave travelling through a specimen of the cement material. The specimen has a particular length, and is at temperature and pressure curing conditions which are found at the wellbore. Pulse velocity is determined by dividing specimen length by transit time. The slurry density of the specimen is then calculated and the mixing rate at the wellbore recorded. Thus the volume of slurry can be worked out by multiplying the time the slurry remains at that density by the mixing rate. The slurry volume's acoustic impedance is equal to the slurry density multiplied by pulse velocity. The annular displacement volume of the wellbore is determined together with map of its acoustic impedance. Casing and liner thicknesses at various locations are compared to theoretical acoustic impedance to produce a map of the attenuation rate around the wellbore. A voltage map can then be drawn up by comparing attenuation to casing diameter. This data is used to produce measures of calculated acoustic impedance which is compared to theoretical values to predict. 48109
Galan, A.
Combined ultrasound methods of concrete testing Elsevier, 350 pp. (1990) The use of ultrasonic methods for the nondestructive evaluation of concrete has many civil engineer applications. This book aims to contribute to the solution of problems encountered in testing concrete nondestructively. A discussion of new combined ultrasonic-pulse methods developed by the author is included. These methods which combine such parameters as pulse velocity in various propagation modes, elastic constants and ultrasonic attenuation are used to test concrete strength. Certain ultrasonic defectoscopy modes in concrete structure are discussed and an integral system for the quality control of concrete structures and members is proposed. 48040
Naish, C.C.; Buttle, D.; Wallace-Sims, R.; O'Brien, T.M.
Acoustic monitoring for corrosion degradation in cemented waste canisters D e p a r t m e n t o f the E n v i r o n m e n t , L o n d o n , (United K i n g d o m ) . D O E - H M I P R R - 9 1 - 0 2 4 (Sep. 1990)
N DT & E International October 1991
This report describes work to investigate acoustic emission as a non- intrusive monitor of corrosion and degradation of cemented wasteforms where the waste is a potentially reactive metal. The acoustic data collected shows good correlation with the corrosion rate as measured by hydrogen gas evolution rates and the electrochemically measured corrosion rates post cement hardening. The technique has been shown to be sensitive in detecting stress caused by expansive corrosion product within the cemented wasteform. The attenuation of the acoustic signal by the wasteform reduced the signal received by the monitoring equipment by a factor of 10 over a distance of approximately 150-400 nun, dependent on the water level in the cement. Full size packages were successfully monitored. It is concluded that the technique offers good potential for monitoring cemented containers of the more reactive metals, for example Magnox and aluminium. 48030
Cent Rech Ind Beton.
Non-destructive on-line tester for cast concrete uses continuous monitoring of propagation speed of ultrasonic signals in setting concrete, for quality control E u r o p e a n Patent No. 4 4 8 , 8 9 6 (2 Oct. 1991) 47879
Gaydeck, P.A.; Burdekin, F.M.; Damaj, W.; John, D.G.;
Payne, P.A. The propagation and attenuation of medium-frequency ultrasonic waves in concrete: a s i g n a l a n a l y t i c a l approach M e a s u r e m e n t Science a n d T e c h n o l o g y , Vol. 1, No. 3, pp. 126-134 (Jan. 1992) The manner in which medium-frequency ultrasonic pulses travelling through concrete are generated, received, digitized and analysed is described. Signal analysis was performed by partitioning the signal into discrete windows in the time domain, corresponding to the emergence of individual wave phenomena within the medium. These windows were then transformed to the frequency domain for subsequent filtering and interpretation. Experimentation combined with theoretical modelling has shown that the appearance and decay of discrete frequency bands depends on both the composition of the concrete, termed the resonance phase, and its external geometry, the geometric phase. 47796
Ohtsu, M.; Shigeishi, M.; lwase, H.; Koyanagi, W.
Determination of crack location, type and orientation in concrete structures by acoustic emission M a g a z i n e o f C o n c r e t e Research, Vol. 43, No. 155, pp. 127-134 (Jun. 1991) In this Paper an advanced AE analysis procedure is proposed. In addition to crack locations, crack types and crack orientation are determined from AE relative amplitudes of the first motions. The procedure classifies cracks into tensile cracks and shear cracks. Based on information of the crack type, the crack orientation is determined; this is the direction of crack opening in the case of tensile cracks, and the direction of sliding motion in the case of shear cracks. The proposed procedure is applied to a pull-out test of an anchor-bolt from a concrete block and a cylinder-tensile test. In the pull out test the opening directions of the tensile cracks is perpendicular to the failure surface, while the directions of sliding motion of the shear cracks are parallel to the failure surface. In the cylinder-tensile test the opening directions of the tensile cracks are perpendicular to the loading direction and all sources are located near the final plane. The proposed procedure is therefore able to determine the microcrack kinematics generated in concrete. 47789
Ohtsu, M.
Diagnostic applications of AE to crack inspection in concrete (In Japanese: E n g l i s h A b s t r a c t ) Journal o f the Society o f Materials Science, Japan, Vol. 40, No. 456, pp. 1191-1196 (Sep. 1991) As a diagnostic application of the acoustic emission (AE) waveform analysis, crack inspection based on the moment tensor analysis is proposed. Because moment tensor components contain information on crack kinematics, the decomposition of eigenvalues of the moment tensor is possible and the contributions of shear motion and tensile motion to crack nucleation can be determined from the ratio of eigenvalnes. Thus, cracks are classified into the type of dominant motion. After the crack types are
265
Ultrasonic and acoustic testing of concrete 48559
Muravin, G.B.; Merman, A.L; Lezvinskaya, L.M.
Acoustic-emission method for estimating the fracture toughness of concrete in large-scale structures and buildings Soviet Journal o f Nondestructive Testing, Vol. 27, No. 3, pp. 166-171 (Nov. 1991) An acoustic-emission technique is developed for estimating the fracture toughness of materials in structures by the calibrated impact method. It is shown that the criteria K l c and J t c can be refined on the basis of data from measurements of the emission parameters. It is established that the reliability of determination of the toughness criteria of heterogeneous materials can be increased up to 30% by acoustic-emission measurements performed with longitudinal mode transducers. 48310
Ouyang, C.; Landis, E.; Shah, S.P.
Damage assessment in concrete using quantitative acoustic emission Journal o f E n g i n e e r i n g M e c h a n i c s , Vol. 117, No. 11, pp. 2 6 8 1 - 2 6 9 8 (Nov. 1991) Quantitative AE techniques were applied to a laboratory study of plain concrete beams under four point loading. Center-notched and off- center-notched beams were loaded in order to produce, respectively, mode I and mixed mode failure. Using AE seismic moment tensor representation, microcracking was characterized as mode I, mode II, or mixed mode. The mode of microcracking was compared to the mode of the visible crack. Most microcrack planes were in a direction normal to the tensile stress for a mode I macrocrack (center-notched), whereas microcrack planes were relatively uniformly distributed for a mixed- mode macrocrack (off-center notched). A large number of mixed-mode microcracks were observed even for the center-notched beam indicating that fracture mechanisms of microcracks may differ from the main macromechanical crack. It is shown that AE measurements can provide a potentially powerful tool in assessing damage. 48286
Chevron Research and Technology Company; (Rutledge, J.M.)
Method for cement evaluation using acoustical l o g s U.S. Patent No. 5 , 0 3 6 , 4 9 6 (30 Jul. 1991) The quality of element material in the annular spaces behind casings or in wellbore liners can be measured using the method described here which produces an evaluation using acoustical log keeping. A sonic test cell is used to determine the transit time of a sound wave travelling through a specimen of the cement material. The specimen has a particular length, and is at temperature and pressure curing conditions which are found at the wellbore. Pulse velocity is determined by dividing specimen length by transit time. The slurry density of the specimen is then calculated and the mixing rate at the wellbore recorded. Thus the volume of slurry can be worked out by multiplying the time the slurry remains at that density by the mixing rate. The slurry volume's acoustic impedance is equal to the slurry density multiplied by pulse velocity. The annular displacement volume of the wellbore is determined together with map of its acoustic impedance. Casing and liner thicknesses at various locations are compared to theoretical acoustic impedance to produce a map of the attenuation rate around the wellbore. A voltage map can then be drawn up by comparing attenuation to casing diameter. This data is used to produce measures of calculated acoustic impedance which is compared to theoretical values to predict. 48109
Galan, A.
Combined ultrasound methods of concrete testing Elsevier, 350 pp. (1990) The use of ultrasonic methods for the nondestructive evaluation of concrete has many civil engineer applications. This book aims to contribute to the solution of problems encountered in testing concrete nondestructively. A discussion of new combined ultrasonic-pulse methods developed by the author is included. These methods which combine such parameters as pulse velocity in various propagation modes, elastic constants and ultrasonic attenuation are used to test concrete strength. Certain ultrasonic defectoscopy modes in concrete structure are discussed and an integral system for the quality control of concrete structures and members is proposed. 48040
Naish, C.C.; Buttle, D.; Wallace-Sims, R.; O'Brien, T.M.
Acoustic monitoring for corrosion degradation in cemented waste canisters D e p a r t m e n t o f the E n v i r o n m e n t , L o n d o n , (United K i n g d o m ) . D O E - H M I P R R - 9 1 - 0 2 4 (Sep. 1990)
N DT & E International October 1991
This report describes work to investigate acoustic emission as a non- intrusive monitor of corrosion and degradation of cemented wasteforms where the waste is a potentially reactive metal. The acoustic data collected shows good correlation with the corrosion rate as measured by hydrogen gas evolution rates and the electrochemically measured corrosion rates post cement hardening. The technique has been shown to be sensitive in detecting stress caused by expansive corrosion product within the cemented wasteform. The attenuation of the acoustic signal by the wasteform reduced the signal received by the monitoring equipment by a factor of 10 over a distance of approximately 150-400 nun, dependent on the water level in the cement. Full size packages were successfully monitored. It is concluded that the technique offers good potential for monitoring cemented containers of the more reactive metals, for example Magnox and aluminium. 48030
Cent Rech Ind Beton.
Non-destructive on-line tester for cast concrete uses continuous monitoring of propagation speed of ultrasonic signals in setting concrete, for quality control E u r o p e a n Patent No. 4 4 8 , 8 9 6 (2 Oct. 1991) 47879
Gaydeck, P.A.; Burdekin, F.M.; Damaj, W.; John, D.G.;
Payne, P.A. The propagation and attenuation of medium-frequency ultrasonic waves in concrete: a s i g n a l a n a l y t i c a l approach M e a s u r e m e n t Science a n d T e c h n o l o g y , Vol. 1, No. 3, pp. 126-134 (Jan. 1992) The manner in which medium-frequency ultrasonic pulses travelling through concrete are generated, received, digitized and analysed is described. Signal analysis was performed by partitioning the signal into discrete windows in the time domain, corresponding to the emergence of individual wave phenomena within the medium. These windows were then transformed to the frequency domain for subsequent filtering and interpretation. Experimentation combined with theoretical modelling has shown that the appearance and decay of discrete frequency bands depends on both the composition of the concrete, termed the resonance phase, and its external geometry, the geometric phase. 47796
Ohtsu, M.; Shigeishi, M.; lwase, H.; Koyanagi, W.
Determination of crack location, type and orientation in concrete structures by acoustic emission M a g a z i n e o f C o n c r e t e Research, Vol. 43, No. 155, pp. 127-134 (Jun. 1991) In this Paper an advanced AE analysis procedure is proposed. In addition to crack locations, crack types and crack orientation are determined from AE relative amplitudes of the first motions. The procedure classifies cracks into tensile cracks and shear cracks. Based on information of the crack type, the crack orientation is determined; this is the direction of crack opening in the case of tensile cracks, and the direction of sliding motion in the case of shear cracks. The proposed procedure is applied to a pull-out test of an anchor-bolt from a concrete block and a cylinder-tensile test. In the pull out test the opening directions of the tensile cracks is perpendicular to the failure surface, while the directions of sliding motion of the shear cracks are parallel to the failure surface. In the cylinder-tensile test the opening directions of the tensile cracks are perpendicular to the loading direction and all sources are located near the final plane. The proposed procedure is therefore able to determine the microcrack kinematics generated in concrete. 47789
Ohtsu, M.
Diagnostic applications of AE to crack inspection in concrete (In Japanese: E n g l i s h A b s t r a c t ) Journal o f the Society o f Materials Science, Japan, Vol. 40, No. 456, pp. 1191-1196 (Sep. 1991) As a diagnostic application of the acoustic emission (AE) waveform analysis, crack inspection based on the moment tensor analysis is proposed. Because moment tensor components contain information on crack kinematics, the decomposition of eigenvalues of the moment tensor is possible and the contributions of shear motion and tensile motion to crack nucleation can be determined from the ratio of eigenvalnes. Thus, cracks are classified into the type of dominant motion. After the crack types are
265