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Low frequency ultrasonic probe for testing concrete structure
quantitatively analyzed based on the rate process theory. In the case of deteriorated concrete, AE events occur actively due to existing critical microcraeks even at low stress level of uniaxial loading. In contrast, AE activity in well- conditioned concrete is only observed just prior to final failure. The discrepancy of these AE activities is reasonably represented by the value of "a" in the rate process theory. To gauge the applicability of the procedure and correlate the deterioration of concrete and the value of "a", fatigue experimems of reinforced concrete slabs were performed and core samples were extracted. The proposed technique is tested by core samples with controlled damage. Results show great promise.
Henkel, D.P.; Wood, J.D. Acoustic emission testing of flexed concrete beams reinforced with bonded surface p l a t e s 41953
Journal o f Acoustic Emission, Vol. 8, Nos. 1-2, pp. 5318-5321 (Jan. - J u n . 1989). Special S u p p l e m e n t - Extended S u m m a r i e s o f Papers to be presented at the World Meeting o n Acoustic Emission, Charlotte, N o a h Carolina, U S A , 20-23 Mar. 1989 A preliminary study is presented of the acoustic emission (AE) response of stressed concrete beams used in structural engineering subject to fracturing under four point bending. The four concrete members in the study had epoxy bonded thin plates of steel, fibreglass, carbon and aramid fibre composites. AE activity was correlated to changes in effective beam modulus, in an attempt to identify AE fracture sources in the beam, and characterize AE signal changes induced by the different plate materials. AE is shown to be a useful method of modelling concrete damage.
Ohtsu, M. Source inversion of acoustic emission for the determination of crack kinematics and kinetics
41895
Jourlaal o f Acoustic Emission, Vol. 8, Nos. 1-2, pp. 5 1 6 2 - 5 1 6 5 (Jan. - J u n . 1989). Special Supplement - Extended S u m m a r i e s o f papers to be presented at the W o r d Meeting on Acoustic Emission, Charlotte, N o r t h Carolina, U S A , 20-23 Mar. 1989 In the present paper, the determination of crack kinematics and kinetics is reported, as a source inversion procedure of AE. The proposed procedure is applied to AE waveforms in pull-out tests of anchor-bolt from concrete block.
Vogel, C.B.; Davis, M.; Guy, J.O. Method for monitoring the goodness of the cement bond to a borehole casing
41866
U.S. Patent No. 4,809,237 (28 Feb. 1989) The quality of cement bonds in borehole casings can be tested using this new method. A logging tool incorporating an acoustic transmitter and receiver is lowered into the borehole. Acoustic radiation from the transmitter is used to insonify the casing and the receiver detects the converted-compressional waves from the casing.
Amoco Corporation Method and apparatus for determining cement conditions 41730
U.S. Patent No. 4,802,145 (31 Jan. 1989) Thickness of the cement around wellbore casings can be determined with this device. Acoustic transducers are set at predetermined distances from each other in contact with the interior surface of the casing. The time that an acoustic pulse takes to travel from one transducer to its neighbour provides a measure of cement thickness.
Western Atlas International, Inc. System for acoustically determining the quality of the cement bond in a cased borehole 41728
U.S. Patent No. 4,805,156 (14 Feb. 1989) This acoustic logging tool can be used to determine the quality of the bond between a borehole wall and its cement casing. A sonde with extendable pads for contact with the surrounding casing is lowered into the borebole. Transducers, arrayed in fours consisting of two transmitters of ultrasonic pulses and two receivers, are disposed on the outer surfaces of the pads. Compensated attenuation between pairs of transmitter and receiver transducers is used to determine the cement bond quality between adjacent transducers.
Stockman, A; Mathieu, P.; Nicholson, P.S. Ultrasonic characterization of model defects in ceramics (Part 3): spherical inclusions in opaque crystallized glass - theory and practice 41646
Materials Evaluation, Vol. 47, No. 3, pp. 358-362 (Mar. 1989) The model for scattering of 25 MHz pulsed focused ultrasound from spherical inclusions in the size range of 50-200 micrometres is compared with actual results for oxide inclusions in crystallized glass. Spherical oxide inclusions are examined in transparent, opaque, crystallized, and partially opaque glass. Signal analysis of the sound waves from inhomogeneities of known size and composition is compared with model predictions based on modified plane-wave theory.
Domone, P.L; Casson, R.B.J. Ultrasonic testing of concrete
41606
Mathematical M o d e l l i n g in Non-Destructive Testing, C a m b r i d g e (United K i n g d o m ) Sop. 1986, pp. 347-356. Edited b y M. B l a k e m o r e and G.A. Georgiou. C l a r e n d o n Press (1988) Time-of-flight ultrasonic testing through hardened concrete is a standard and widely used technique. The stainless steel transducers have lead zirconate titanate ceramic piezoelectric elements. A commercial instrument, the PUND IT, is used for testing. Pulse velocity (UPV) through the concrete can be measured using PUND IT and recent experimental work is described. The implications of mathematical modelling using UPV is also discussed.
272
Amoco Corporation Method and apparatus for determining cement conditions 41520
U.S. Patent No. 4,800,537 (24 Jan. 1989) This patent describes an acoustic method for determining the condition of cement next to casings in wellbores. Transducers are positioned internally and externally to the casing. Ultrasonic velocity measurements for transmission through the concrete casing are compared to known standard values and the results used to determine whether any foreign bodies or voids are present.
Kabir, M.H.; Dos, M.K. Non destructive testing in evaluation of quality of concrete of a multistoried building in Dhaka City 41199
Proceedings o f the 12th World Conference on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1596-1598. Edited by J. B o o g a a r d a n d G.M. v a n Dijk, Elsevier, 1989. This paper reports a comparative study of results from cylinder tests and non destructive tests (NDT), using the ultrasonic pulse techniques, conducted on concrete of a 25 storied office building in Dhaka City. Statistical comparisons performed on strength values and their variations on global and local bases show reasonable degrees of agreement.
Ohta, K.; Watanabe, T.; Jinzhong, Y.; Daft, T.; HenghuL C. Low frequency ultrasonic probe for testing concrete structure
41197
Proceedings o f the t 2 t h World C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1582-1585. Edited by J. B o o g a a r d and G.M. v a n Dijk, Elsevier, 1989. In order to design a low frequency probe for testing concrete, a multi- layer piezo-electric transducer has been prepared and its characteristics have been analyzed by means of Mason's equivalent circuit. The resonator's material and its thickness must be selected according to the analysis. The frequency and impulse response of probe are shown. The probe must be matched acoustically to the specimen and also matched electrically to the equipment.
Di Maio, A.A.; Traversa, L.P. Estimation of concrete strength in situ using nondestructive testing 41196
Proceedings o f the 12th World C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1579-1581. Edited b y J. B o o g a a r d a n d G.M. van Dijk, Elsevier, 1989. In this paper studies are presented about the evaluation of concrete quality in a wall corresponding to a two years old structure. The effective strength was realized using the ultrasonic method, the hammer rebound and the Break-Off test. Correlation equations were used which had previously been obtained in concrete elaborated with materials of similar characteristics. Correction factors for moisture content, carbonation and path length of the wave were also employed. The verification of the effective strength was done by means of compressive tests of cores drilled out of the structural element.
Amoco Corporation Method for acoustic reverberation removal
41135
U.S. Patent No. 4,796,237 (3 Jan. 1989) Defects in cement in wellbores can be determined using this downhole tool. A transducer within the tool transmits pulses of acoustic energy. The time delay (DELTA t) between transmission of a pulse and the reception of the first acoustic reverberation is measured. Positive and negative pulses of energy are used to establish a reverberation pattern.
Ogura, Y.; Miyajima, T.; Takishita, T.; Ohtake, K.; Akutsu, Y. Measurement of crack depths in concrete
41040
Proceedings o f the 12th World Conference on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1249-1254. Edited by J. B o o g a a r d and G.M. v a n Dijk, Elsevier, 1989. A study was made on the low-frequency ultrasonic measurement of depths of surface opening cracks in concrete structures. Basic tests were conducted to obtain the relationship between crack depth and ultrasonic propagation time/reception frequency by varying the ultrasonic mode, frequency and distance between probe, revealing that with a suitable ultrasonic mode selected, there were correlations between crack depth and propagation time/reception frequency. The standard deviations with these methods were below 9.0 mm.
Teodoru, G.V.M. A new answer to an old question: the non-destructive testing of concrete
41039
Proceedings o f the 12th W o r l d C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1237-1242, Edited by J. B o o g a a r d a n d G.M. v a n Dijk, Elsevier, 1989. Details are presented about this method of multiple correlation. The method is based on simultaneous non-destructive tests (NDT): both ultrasonic pulse velocity (UPV) and attenuation and rebound indices of Schmidt Hammer type N are used. The utility of this concept for multiple correlation in the control of the concrete quality, especially in a plant for precast elements, is evident both directly for the assessment of the compressive strength of concrete, as well as from statistical quality analysis. Even when mathematically the degree of accuracy of predicted strength increases, the possibility of errors in this assessment is greatly reduced.
Naish, C.C.; O'Brien, T.M. Acoustic monitoring techniques for corrosion degradation in cemented waste c a n i s t e r s
40736
United K i n g d o m Atomic E n e r g y Authority, Harwell, A E R E - G - 5 0 1 1 , 5 pp. (Feb. 1989)
N DT & E International October 1991
Henkel, D.P.; Wood, J.D. Acoustic emission testing of flexed concrete beams reinforced with bonded surface p l a t e s 41953
Journal o f Acoustic Emission, Vol. 8, Nos. 1-2, pp. 5318-5321 (Jan. - J u n . 1989). Special S u p p l e m e n t - Extended S u m m a r i e s o f Papers to be presented at the World Meeting o n Acoustic Emission, Charlotte, N o a h Carolina, U S A , 20-23 Mar. 1989 A preliminary study is presented of the acoustic emission (AE) response of stressed concrete beams used in structural engineering subject to fracturing under four point bending. The four concrete members in the study had epoxy bonded thin plates of steel, fibreglass, carbon and aramid fibre composites. AE activity was correlated to changes in effective beam modulus, in an attempt to identify AE fracture sources in the beam, and characterize AE signal changes induced by the different plate materials. AE is shown to be a useful method of modelling concrete damage.
Ohtsu, M. Source inversion of acoustic emission for the determination of crack kinematics and kinetics
41895
Jourlaal o f Acoustic Emission, Vol. 8, Nos. 1-2, pp. 5 1 6 2 - 5 1 6 5 (Jan. - J u n . 1989). Special Supplement - Extended S u m m a r i e s o f papers to be presented at the W o r d Meeting on Acoustic Emission, Charlotte, N o r t h Carolina, U S A , 20-23 Mar. 1989 In the present paper, the determination of crack kinematics and kinetics is reported, as a source inversion procedure of AE. The proposed procedure is applied to AE waveforms in pull-out tests of anchor-bolt from concrete block.
Vogel, C.B.; Davis, M.; Guy, J.O. Method for monitoring the goodness of the cement bond to a borehole casing
41866
U.S. Patent No. 4,809,237 (28 Feb. 1989) The quality of cement bonds in borehole casings can be tested using this new method. A logging tool incorporating an acoustic transmitter and receiver is lowered into the borehole. Acoustic radiation from the transmitter is used to insonify the casing and the receiver detects the converted-compressional waves from the casing.
Amoco Corporation Method and apparatus for determining cement conditions 41730
U.S. Patent No. 4,802,145 (31 Jan. 1989) Thickness of the cement around wellbore casings can be determined with this device. Acoustic transducers are set at predetermined distances from each other in contact with the interior surface of the casing. The time that an acoustic pulse takes to travel from one transducer to its neighbour provides a measure of cement thickness.
Western Atlas International, Inc. System for acoustically determining the quality of the cement bond in a cased borehole 41728
U.S. Patent No. 4,805,156 (14 Feb. 1989) This acoustic logging tool can be used to determine the quality of the bond between a borehole wall and its cement casing. A sonde with extendable pads for contact with the surrounding casing is lowered into the borebole. Transducers, arrayed in fours consisting of two transmitters of ultrasonic pulses and two receivers, are disposed on the outer surfaces of the pads. Compensated attenuation between pairs of transmitter and receiver transducers is used to determine the cement bond quality between adjacent transducers.
Stockman, A; Mathieu, P.; Nicholson, P.S. Ultrasonic characterization of model defects in ceramics (Part 3): spherical inclusions in opaque crystallized glass - theory and practice 41646
Materials Evaluation, Vol. 47, No. 3, pp. 358-362 (Mar. 1989) The model for scattering of 25 MHz pulsed focused ultrasound from spherical inclusions in the size range of 50-200 micrometres is compared with actual results for oxide inclusions in crystallized glass. Spherical oxide inclusions are examined in transparent, opaque, crystallized, and partially opaque glass. Signal analysis of the sound waves from inhomogeneities of known size and composition is compared with model predictions based on modified plane-wave theory.
Domone, P.L; Casson, R.B.J. Ultrasonic testing of concrete
41606
Mathematical M o d e l l i n g in Non-Destructive Testing, C a m b r i d g e (United K i n g d o m ) Sop. 1986, pp. 347-356. Edited b y M. B l a k e m o r e and G.A. Georgiou. C l a r e n d o n Press (1988) Time-of-flight ultrasonic testing through hardened concrete is a standard and widely used technique. The stainless steel transducers have lead zirconate titanate ceramic piezoelectric elements. A commercial instrument, the PUND IT, is used for testing. Pulse velocity (UPV) through the concrete can be measured using PUND IT and recent experimental work is described. The implications of mathematical modelling using UPV is also discussed.
272
Amoco Corporation Method and apparatus for determining cement conditions 41520
U.S. Patent No. 4,800,537 (24 Jan. 1989) This patent describes an acoustic method for determining the condition of cement next to casings in wellbores. Transducers are positioned internally and externally to the casing. Ultrasonic velocity measurements for transmission through the concrete casing are compared to known standard values and the results used to determine whether any foreign bodies or voids are present.
Kabir, M.H.; Dos, M.K. Non destructive testing in evaluation of quality of concrete of a multistoried building in Dhaka City 41199
Proceedings o f the 12th World Conference on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1596-1598. Edited by J. B o o g a a r d a n d G.M. v a n Dijk, Elsevier, 1989. This paper reports a comparative study of results from cylinder tests and non destructive tests (NDT), using the ultrasonic pulse techniques, conducted on concrete of a 25 storied office building in Dhaka City. Statistical comparisons performed on strength values and their variations on global and local bases show reasonable degrees of agreement.
Ohta, K.; Watanabe, T.; Jinzhong, Y.; Daft, T.; HenghuL C. Low frequency ultrasonic probe for testing concrete structure
41197
Proceedings o f the t 2 t h World C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1582-1585. Edited by J. B o o g a a r d and G.M. v a n Dijk, Elsevier, 1989. In order to design a low frequency probe for testing concrete, a multi- layer piezo-electric transducer has been prepared and its characteristics have been analyzed by means of Mason's equivalent circuit. The resonator's material and its thickness must be selected according to the analysis. The frequency and impulse response of probe are shown. The probe must be matched acoustically to the specimen and also matched electrically to the equipment.
Di Maio, A.A.; Traversa, L.P. Estimation of concrete strength in situ using nondestructive testing 41196
Proceedings o f the 12th World C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1579-1581. Edited b y J. B o o g a a r d a n d G.M. van Dijk, Elsevier, 1989. In this paper studies are presented about the evaluation of concrete quality in a wall corresponding to a two years old structure. The effective strength was realized using the ultrasonic method, the hammer rebound and the Break-Off test. Correlation equations were used which had previously been obtained in concrete elaborated with materials of similar characteristics. Correction factors for moisture content, carbonation and path length of the wave were also employed. The verification of the effective strength was done by means of compressive tests of cores drilled out of the structural element.
Amoco Corporation Method for acoustic reverberation removal
41135
U.S. Patent No. 4,796,237 (3 Jan. 1989) Defects in cement in wellbores can be determined using this downhole tool. A transducer within the tool transmits pulses of acoustic energy. The time delay (DELTA t) between transmission of a pulse and the reception of the first acoustic reverberation is measured. Positive and negative pulses of energy are used to establish a reverberation pattern.
Ogura, Y.; Miyajima, T.; Takishita, T.; Ohtake, K.; Akutsu, Y. Measurement of crack depths in concrete
41040
Proceedings o f the 12th World Conference on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1249-1254. Edited by J. B o o g a a r d and G.M. v a n Dijk, Elsevier, 1989. A study was made on the low-frequency ultrasonic measurement of depths of surface opening cracks in concrete structures. Basic tests were conducted to obtain the relationship between crack depth and ultrasonic propagation time/reception frequency by varying the ultrasonic mode, frequency and distance between probe, revealing that with a suitable ultrasonic mode selected, there were correlations between crack depth and propagation time/reception frequency. The standard deviations with these methods were below 9.0 mm.
Teodoru, G.V.M. A new answer to an old question: the non-destructive testing of concrete
41039
Proceedings o f the 12th W o r l d C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands), 23-28 Apr. 1989, Vol. 2, pp. 1237-1242, Edited by J. B o o g a a r d a n d G.M. v a n Dijk, Elsevier, 1989. Details are presented about this method of multiple correlation. The method is based on simultaneous non-destructive tests (NDT): both ultrasonic pulse velocity (UPV) and attenuation and rebound indices of Schmidt Hammer type N are used. The utility of this concept for multiple correlation in the control of the concrete quality, especially in a plant for precast elements, is evident both directly for the assessment of the compressive strength of concrete, as well as from statistical quality analysis. Even when mathematically the degree of accuracy of predicted strength increases, the possibility of errors in this assessment is greatly reduced.
Naish, C.C.; O'Brien, T.M. Acoustic monitoring techniques for corrosion degradation in cemented waste c a n i s t e r s
40736
United K i n g d o m Atomic E n e r g y Authority, Harwell, A E R E - G - 5 0 1 1 , 5 pp. (Feb. 1989)
N DT & E International October 1991