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A survey of developments in ultrasonic NDE of concrete
N DT Abstracts 56069
Ar~ M.Z.; Turner, C.W.
mathematical theory and production rule respectively. Finally, an example of detection is provided. All computing data and results of testing can be output in the form of graphic or literal through the CRT or printer.
Design of low frequency acoustic waveguide probe for NDT of concrete structures Ultrasonics International 93 C o n f e r e n c e Proceedings, Vienna (Austria), 6-8 Jul. 1993. pp. 235-238. Butterworth-Heinemann Ltd. (1993) ISBN 0750618779 Cladded waveguides have been investigated numerically and experimentally for use as novel acoustic waveguide probes in low frequency NDT applications because they offer increased sensitivity, wider bandwidth and higher resolution. Attention is focussed on cladding materials which are Iossy and therefore most useful as a damping medium to absorb unwanted acoustic energy. Our numerical technique solves the dispersion equation for the lowest symmetrical Ssub(O) mode of X-Y-X sandwich structures. We present results for the wave velocity and damping factor for a variety of materials and parameters. Experimental results are also presented for a wideband acoustic waveguide probe (AWP) designed using these results. 55962
55322
Ph.D. Thesis, University o f Manchester (UK), Department o f Civil and Structural Engineering, 423 pp. (Jun. 1990) Analytical and laboratory studies of stress wave propagation have been carried out to develop a basis for a nondestructive test method to detect corrosion and flaws in embedded steel components in reinforced and prestressed concrete. The technique, which is referred to as the indirect method or the pitch-catch technique, involves introducing an ultrasonic signal into a test object by an ultrasonic transducer, and monitoring the reflections of the signal from internal or external boundaries such as bar/concrete or concrete/air interfaces or from defects such as corrosion or flaws, using other ultrasonic receivers located close to the radiator. A ray tracing model using computer synthesis has been developed. The model has been verified by comparison with experiments from water and concrete samples. Equations have been derived to predict the attenuation of signals from bars embedded in concrete with different surface conditions and sizes. Moreover the attenuation of ultrasonic signals in concrete has been studied. An equation has been derived from experimental results to estimate the attenuation loss due to scattering and absorption for high strength concrete. Successes achieved in the laboratory suggest that the pitch-catch method has the potential to become a reliable field technique for detecting corrosion and flaws within concrete structures.
Sack, D.A.; Olson, L.D.; Kline, T.R.; Yates, G.A.
Nondestructive testing of older concrete bridges: a case h i s t o r y of t h e S E P T A Manayunk bridge 9th Annual International Bridge Conference, Pittsburgh, Pennsylvania (United States), 15-17 Jun. 1992. pp. 405-413. Engineers Society o f Western Pennsylvania(1992) Included in this paper is an ove,wiew of the Nondestructive Evaluation (NDE) program carried out on the bridge, and a summary of the results of this program. Also included in this presentation are detailed descriptions of the NDE methods used in the evaluation. These include the Ultrasonic Pulse Velocity (UPV) and Impact Echo (IE) methods. The UPV method was used on the relatively thin walls interior to the arch where access was available on both sides, while the IE method was used on these as well as on decks, abutments, and other massive concrete structural members. 55939
55315
strength
assessment
of
International Conference on Nondestructive Testing o f Concrete in the Infrastructure, Dearborn, Michigan (United States), 9-11 Jun. 1993. pp. 550-558. Society for Experimental Mechanics, Inc., (1993) ISBN 10912053429 The paper presents the preliminary results of a study comparing the information obtained by optical microscopy and scanning acoustic microscopy when detecting flaws in concrete. The results show that the detectability of the cracks is greater with the acoustic microscope than with the optical microscope, in the case where the attack on concrete is followed by the formation of deposits, such as in the case of sulfate attack, scanning acoustic microscopy is more capable of locating voids with deposits than optical microscopy.
concrete-based
Engineering Data M a n a g e m e n t , inc., Fort Collins, Colorado (United States), PB94-145851/GAR, 80pp. (Jul. 1987) The research was directed at evaluating the feasibility of using a sonic wave nondestructive evaluation (NDE) method to provide cost- efficient, reliable determination of the compression strength of individual concrete members. It involved: (1) collection of NDE data from concrete cylinders in the laboratory; (2) development of models to predict the compression strength of the cylinders, and (3) evaluation of the ability of the developed models to predict concrete strength in comparison to current strength prediction techniques. The standard error of estimate (SEE) was used to define the reliability of the NDE models. The resulting SEEs for the concrete cylinders are 230 psi for the pendulum-based NDE and 232 psi for the impulse hammer-based NDE. The results have verified the validity of the sonic wave spectral analysis NDE approach.
55313 Hussien,M.; Morgano, M. S t r u c t u r a l i n t e g r i t y evaluation of concrete piles from stress
wave measurements International Conference on Nondestructive Testing o f Concrete in the Infrastructure, Dearborn, Michigan (United States), 9-11 Jun. 1993. pp. 391-408. Society for Experimental Mechanics, Inc., (1993) ISBN 10912053429 Piles are deep foundation elements used to carry heavy structural loads. Measurements of stress waves in driven precast piles under hammer impacts are routinely obtained for evaluating pile beating capacity, driving stresses and structural integrity. After installation, both driven and cast-in-place piles may be evaluated for structural integrity by measuring pile top stress waves generated by small hand-held hammer impacts and wave reflections. This paper presents discussions on the principles, application, and limitations of these "high" and "low" strain testing methods. Six illustrative case histories are also included.
55585 Popovics,J.S.; Rose, J.L. A survey of developments in ultrasonic NDE of concrete IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 41, No. 1, pp. 140-143 (Jan. 1994) The goal of this paper is to develop an understanding of the current state of ultrasonic nondestructive evaluation in the concrete community. Methods supplemental to the less than satisfactory procedure specified in ASTM C-597 are discussed. Following an introductory problem statement, a literature review concerning the existing use of stress waves for the nondestructive evaluation of concrete is presented. An examination of current practice is offered. Next, new approaches are selected and reviewed from the current literature. Where appropriate, potential benefits and pitfalls of each new technique, as applied to concrete, will be discussed. 55541
Tittmann,B.R.; Aligizaki, K.K.; Gordon, G.A.
Comparison between optical microscopy and scanning acoustic microscopy for detecting flaws in concrete
Stewart, A.H.; Goodman, J.R.
Nondestructive structures
Damaj, W.T.
Ultrasonic inspection of concrete structures to detect the condition of embedded steel components
55312
Sack, D.A.; OIson, L.D.
Advanced NDT methods for concrete structures
Jiecheng, L.; Zhenquan, Z.; Yingxia, D.
International Conference on Nondestructive Testing o f Concrete in the Infrastructure, Dearborn, Michigan (United States), 9-11 Jun. 1993. pp. 353-369. Society for Experimental Mechanics, Inc., (1993) ISBN 10912053429 This paper presents several advances in methods and equipment for sonic and ultrasonic Non-Destructive Testing (NDT) of concrete structures. The advances include the use of the Spectral Analysis of Surface Waves (SASW) method in the NDT of concrete. This method allows the determination of the shear wave velocity profile versus depth for any layered system and is particularly applicable to testing pavements, slabs, tunnels, shaft liners, and massive concrete structures. Also discussed is the development of high-speed scanning technology for the performance of a number of NDT methods which have traditionally been performed on a point-by-point basis. Test data is presented to illustrate the applications of the scanner to Ultrasonic Pulse Velocity, Impact Echo, and SASW methods.
Studies on the system of ultrasonic test of concrete Proceedings o f the 20th International S y m p o s i u m on Acoustical Imaging, Nanjing (China), 12-14 Sep. 1992. pp. 209-216. Edited by Y. Wei and B. Gu. Plenum Press, Vol. 20(1993) ISBN 0-30644585-9 Based upon the correlation between interior flaw and parameters such as ultrasonic velocity, the first ultrasonic amplitude and the received ultrasonic frequency, a microcomputer testing system has been developed, which comprises of three elementary parts, namely, data sampling, signal processing and flaw judging. It can be applied in nondestructive testing of the internal flaws of the structure concrete. This paper concentrates on the introduction of the fast calculating algorithms of audiotime and the first ultrasonic amplitude, the spectral analyzing method of the received waveform and the two flaw judging procedures on the basis of fuzzy
258
Ar~ M.Z.; Turner, C.W.
mathematical theory and production rule respectively. Finally, an example of detection is provided. All computing data and results of testing can be output in the form of graphic or literal through the CRT or printer.
Design of low frequency acoustic waveguide probe for NDT of concrete structures Ultrasonics International 93 C o n f e r e n c e Proceedings, Vienna (Austria), 6-8 Jul. 1993. pp. 235-238. Butterworth-Heinemann Ltd. (1993) ISBN 0750618779 Cladded waveguides have been investigated numerically and experimentally for use as novel acoustic waveguide probes in low frequency NDT applications because they offer increased sensitivity, wider bandwidth and higher resolution. Attention is focussed on cladding materials which are Iossy and therefore most useful as a damping medium to absorb unwanted acoustic energy. Our numerical technique solves the dispersion equation for the lowest symmetrical Ssub(O) mode of X-Y-X sandwich structures. We present results for the wave velocity and damping factor for a variety of materials and parameters. Experimental results are also presented for a wideband acoustic waveguide probe (AWP) designed using these results. 55962
55322
Ph.D. Thesis, University o f Manchester (UK), Department o f Civil and Structural Engineering, 423 pp. (Jun. 1990) Analytical and laboratory studies of stress wave propagation have been carried out to develop a basis for a nondestructive test method to detect corrosion and flaws in embedded steel components in reinforced and prestressed concrete. The technique, which is referred to as the indirect method or the pitch-catch technique, involves introducing an ultrasonic signal into a test object by an ultrasonic transducer, and monitoring the reflections of the signal from internal or external boundaries such as bar/concrete or concrete/air interfaces or from defects such as corrosion or flaws, using other ultrasonic receivers located close to the radiator. A ray tracing model using computer synthesis has been developed. The model has been verified by comparison with experiments from water and concrete samples. Equations have been derived to predict the attenuation of signals from bars embedded in concrete with different surface conditions and sizes. Moreover the attenuation of ultrasonic signals in concrete has been studied. An equation has been derived from experimental results to estimate the attenuation loss due to scattering and absorption for high strength concrete. Successes achieved in the laboratory suggest that the pitch-catch method has the potential to become a reliable field technique for detecting corrosion and flaws within concrete structures.
Sack, D.A.; Olson, L.D.; Kline, T.R.; Yates, G.A.
Nondestructive testing of older concrete bridges: a case h i s t o r y of t h e S E P T A Manayunk bridge 9th Annual International Bridge Conference, Pittsburgh, Pennsylvania (United States), 15-17 Jun. 1992. pp. 405-413. Engineers Society o f Western Pennsylvania(1992) Included in this paper is an ove,wiew of the Nondestructive Evaluation (NDE) program carried out on the bridge, and a summary of the results of this program. Also included in this presentation are detailed descriptions of the NDE methods used in the evaluation. These include the Ultrasonic Pulse Velocity (UPV) and Impact Echo (IE) methods. The UPV method was used on the relatively thin walls interior to the arch where access was available on both sides, while the IE method was used on these as well as on decks, abutments, and other massive concrete structural members. 55939
55315
strength
assessment
of
International Conference on Nondestructive Testing o f Concrete in the Infrastructure, Dearborn, Michigan (United States), 9-11 Jun. 1993. pp. 550-558. Society for Experimental Mechanics, Inc., (1993) ISBN 10912053429 The paper presents the preliminary results of a study comparing the information obtained by optical microscopy and scanning acoustic microscopy when detecting flaws in concrete. The results show that the detectability of the cracks is greater with the acoustic microscope than with the optical microscope, in the case where the attack on concrete is followed by the formation of deposits, such as in the case of sulfate attack, scanning acoustic microscopy is more capable of locating voids with deposits than optical microscopy.
concrete-based
Engineering Data M a n a g e m e n t , inc., Fort Collins, Colorado (United States), PB94-145851/GAR, 80pp. (Jul. 1987) The research was directed at evaluating the feasibility of using a sonic wave nondestructive evaluation (NDE) method to provide cost- efficient, reliable determination of the compression strength of individual concrete members. It involved: (1) collection of NDE data from concrete cylinders in the laboratory; (2) development of models to predict the compression strength of the cylinders, and (3) evaluation of the ability of the developed models to predict concrete strength in comparison to current strength prediction techniques. The standard error of estimate (SEE) was used to define the reliability of the NDE models. The resulting SEEs for the concrete cylinders are 230 psi for the pendulum-based NDE and 232 psi for the impulse hammer-based NDE. The results have verified the validity of the sonic wave spectral analysis NDE approach.
55313 Hussien,M.; Morgano, M. S t r u c t u r a l i n t e g r i t y evaluation of concrete piles from stress
wave measurements International Conference on Nondestructive Testing o f Concrete in the Infrastructure, Dearborn, Michigan (United States), 9-11 Jun. 1993. pp. 391-408. Society for Experimental Mechanics, Inc., (1993) ISBN 10912053429 Piles are deep foundation elements used to carry heavy structural loads. Measurements of stress waves in driven precast piles under hammer impacts are routinely obtained for evaluating pile beating capacity, driving stresses and structural integrity. After installation, both driven and cast-in-place piles may be evaluated for structural integrity by measuring pile top stress waves generated by small hand-held hammer impacts and wave reflections. This paper presents discussions on the principles, application, and limitations of these "high" and "low" strain testing methods. Six illustrative case histories are also included.
55585 Popovics,J.S.; Rose, J.L. A survey of developments in ultrasonic NDE of concrete IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 41, No. 1, pp. 140-143 (Jan. 1994) The goal of this paper is to develop an understanding of the current state of ultrasonic nondestructive evaluation in the concrete community. Methods supplemental to the less than satisfactory procedure specified in ASTM C-597 are discussed. Following an introductory problem statement, a literature review concerning the existing use of stress waves for the nondestructive evaluation of concrete is presented. An examination of current practice is offered. Next, new approaches are selected and reviewed from the current literature. Where appropriate, potential benefits and pitfalls of each new technique, as applied to concrete, will be discussed. 55541
Tittmann,B.R.; Aligizaki, K.K.; Gordon, G.A.
Comparison between optical microscopy and scanning acoustic microscopy for detecting flaws in concrete
Stewart, A.H.; Goodman, J.R.
Nondestructive structures
Damaj, W.T.
Ultrasonic inspection of concrete structures to detect the condition of embedded steel components
55312
Sack, D.A.; OIson, L.D.
Advanced NDT methods for concrete structures
Jiecheng, L.; Zhenquan, Z.; Yingxia, D.
International Conference on Nondestructive Testing o f Concrete in the Infrastructure, Dearborn, Michigan (United States), 9-11 Jun. 1993. pp. 353-369. Society for Experimental Mechanics, Inc., (1993) ISBN 10912053429 This paper presents several advances in methods and equipment for sonic and ultrasonic Non-Destructive Testing (NDT) of concrete structures. The advances include the use of the Spectral Analysis of Surface Waves (SASW) method in the NDT of concrete. This method allows the determination of the shear wave velocity profile versus depth for any layered system and is particularly applicable to testing pavements, slabs, tunnels, shaft liners, and massive concrete structures. Also discussed is the development of high-speed scanning technology for the performance of a number of NDT methods which have traditionally been performed on a point-by-point basis. Test data is presented to illustrate the applications of the scanner to Ultrasonic Pulse Velocity, Impact Echo, and SASW methods.
Studies on the system of ultrasonic test of concrete Proceedings o f the 20th International S y m p o s i u m on Acoustical Imaging, Nanjing (China), 12-14 Sep. 1992. pp. 209-216. Edited by Y. Wei and B. Gu. Plenum Press, Vol. 20(1993) ISBN 0-30644585-9 Based upon the correlation between interior flaw and parameters such as ultrasonic velocity, the first ultrasonic amplitude and the received ultrasonic frequency, a microcomputer testing system has been developed, which comprises of three elementary parts, namely, data sampling, signal processing and flaw judging. It can be applied in nondestructive testing of the internal flaws of the structure concrete. This paper concentrates on the introduction of the fast calculating algorithms of audiotime and the first ultrasonic amplitude, the spectral analyzing method of the received waveform and the two flaw judging procedures on the basis of fuzzy
258