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Evaluating structures using impulse radar and sonic techniques
N DT Abstracts removal of the old superstructure. The objective was to assess the condition of the slab, which was to be used as a foundation for canting new multisturey structures on the redew~Joped site. Ground probing radar (gpr) was used to investigate the thickness and integrity of the concrete, and to locate pipes and steelwork and othex hidden obstructions. A series of cores were extracted from the concrete to establish it's strength and quality. 52399
52276 Wilson,J.G. Possible applications of the electrical properties of concrete to quality assurance and integrity testing Non-Destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr. 1993. Vol. 2, pp. 869-882. Edited by J.H. Bungey. The British Institute of NDT (1993) This paper discusses the factors which affect the electrical properties of concrete, and shows how these mast be related to the mechanical behaviour. Techniques for measuring the electrical properties at different fiequencies are described. Possible application of the electrical properties to the measurement of the fractional water content of fresh concrete, the development of mechanical structure, and propagation calculations for the penetration of radar waveforms used in ground-probe radars, are discussed.
Fenning, P J; Jack, A G; Veness, J K
Ground probing radar applications in site investigation Non-destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. 2, pp 113-140. Edited by J H Bungey. The British Institute of NDT (1993) It is suggested that the introduction of ground probing radar systems which are based on proven seismic reflection methodology will overcome some of the misapplications of the past. Reference is made to the requirement for radar signal propagation velocity determination to be made on site and the pre-survey requirement of assessing theoretical ground radar applicability before commencing a radar survey. Examples of case histories are given. 52398
52132
Forde, M.C.; McCavitt, N.
Sonic NDT and r a d a r testing of masonry Non-Destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr. 1993. Vol. 2, pp. 489-505. Edited by J.H. Bungey. The British Institute of NDT (1993) The various methods of non-destructively testing masorLryare reviewed. The value of rotary coring and partially destructive investigation techniques are described in relation to the evaluation of masonry. The principles of digital sonic time domain testing, digital sonic frequency domain testing and digital time domain radar testing are explained and described in relation to applications to masonry bridges and retaining wall structures. From the case studies it is shown that the techniques of digital sonic impulse hammer testing and digital impulse radar testing are complementary in nature and can be used to cost effectively identify the geomeuies of masonry bridges in addition to fault detection, location.
Smale, D C
Impulse r a d a r - detail without destruction Non-destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. I, pp 97-111. Edited by J H Bungey. The British Institute of NDT (1993) Following a brief introduction covering the theoretical background to the Impulse Radar Method, the paper tackles the major problems with the technique in its current state of development and suggests possible ways forward in the resolution of these problems within the future.
52131 Broomfield, J.P.
The assessment of corrosion of reinforcing steel on highway bridges
52397 Hobbs, C P; Temple, J A G; Hillier, M J R a d a r inspection of civil engineering structures Non-destructive Testing in Chril Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. 1, pp 79-96. Edited by J H Bungey. The British Institute of NDT (1993) Despite the potential of radar, ~he civil engineering community in the UK has been slow to adopt the technology. This is partly because some claims about the capabilities of radar have been overstated, and also because the data currently generated can be difficult for the non- specialist to understand. Our work has used two approaches to address these specific problems. First, signal processing combined with a well-defined inspection procedure has been used to produce clearer images. Second, modelling of assumed subsurface structure is carried out to yield theoretical images which can be used to optimise inspections und aid in interpretation of real datafiles. The advantages over typical radar data are demonstrated by example. 52395
Non-Destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr. 1993. Vol. 2, pp. 551-566. Edited by J.H. Bungey. The British Institute of NDT (1993) This paper describes the results of a 31/2 year research program on non-destructive test techniques for measuring corrosion and corrosion damage on bridges. The work was done in the USA and was concerned with reinforced concrete bridge elements suffering from corrosion due to sea salt and deicing salt penetration. The research involved assessment of linear polarisation techniques for corrosion rate measurement and vehicle mounted radar techniques for measuring delaminations on bridge decks. Rapid field techniques for measuring the chloride content of concrete, the effectiveness of concrete sealers and waterproof membranes, and concrete permeability were also developed. An overall methodology of corrosion for reinforced concrete is discussed and a field evaluation of a bridge support slrueture in the UK is presented.
Ballard,G S
Non destructive assessment of pavement design and new build quality
51827
Non-destructive Testing in Civil Engineering, Liverpool, (United Kingdom), 14-16 Apr 1993. Vol. 1, pp 391-404. Edited by J H Bungey. The British Institute of NDT (1993) Pulsed Radio Echo Sounding (Ground Radar) is used to assess the structural composition of pavements and to provide information on thickness, bond and density for correlation with and correction of surface strength measurements. The construction of an experimental pavement, is examined: continuous assessment by radar shows wide deviation from the design specification, and faults of bond and compaction in the pavement itself, both in the experimental tapered sections and the standard parallel layer sections. The effect of these defects on apparent pavement strength and projected life is considered.
Decommissioning and Demolition 1992, Manchester (United Kingdom), 25-26 Mar. 1992. pp. 118-122. Edited by I.L. Whyte, Thomas Telford Ltd. (1992) This paper outlines new and sophisticated impulse digital nondestructive testing techniques. The techniques used include impulse digital time domain testing, impulse digital frequency domain testing and digital impulse radar testing. The techniques are described in relation to applications to concrete bridges. It is shown that the techniques of impulse sonic and radar testing are complementary in nature and can be used cost effectively to identify the geometries of structures in addition prior to decommissioning.
52361
Uomotor,T; Misra, S
Non destructive evaluation developments in J a p a n
of
RC
structures
Forde, M.C.; McCavitt, N.; Batchelor, AJ.
Evaluating structures using impulse r a d a r and sonic techniques
recent
Non-destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. 1, pp 65-77. Edited by J H Bungey. The British Institute of NDT (1993) Although new NDT techniques are not well understood by concrete ungiueers, they are finding ways to apply such techniques as ultra sonic, acoustic emission, electro- magnetic technique, x-ray, thermograph, radar, etc, to evaluate crack distribution, crack depth, location and volume of large voids, location and size of reinforcements, degree of reinforcement corrosion, etc. This paper aims to introduce and discuss how NDT is being or going to be used in the field of concrete for civil engineering structures in Japan.
317
51357 Kratochvil, G.; Fenner, T.; Benson, R. SIR technology helps ensure safe landings for N A S A Materials Evaluation, Vol. 50, No. 12, pp. 1412-1414 (Dec. 1992) When a U.S. space shuttle lands, most often it touches down on an unpaved runway at Edwards Air Force Base in California's Mojave Desert. Its 190,000 pounds (86,184 kg) hit the natural lake-bed runway at 185 knots, placing tremendous stresses on the soil of the desert floor. Three times-once during a landing and twice as the shuttle was being towed from the lakebed landing strip to the edge of the lakebed-the wheels broke through the crust of the desert floor. To prevent danger to shuttle crews and damage to the spacecraft, NASA's shuttle program office instituted regular, programmed inspections of the landing strips in 1988. These investigations, managed by the Geologic Science Advisor, began as visual checks but now use a subsurface interface radar (SIR) system designed and manufactured by Geophysical Survey Systems, Inc., to ensure that the lake-bed runways will be free of unseen fissures and voids.
52276 Wilson,J.G. Possible applications of the electrical properties of concrete to quality assurance and integrity testing Non-Destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr. 1993. Vol. 2, pp. 869-882. Edited by J.H. Bungey. The British Institute of NDT (1993) This paper discusses the factors which affect the electrical properties of concrete, and shows how these mast be related to the mechanical behaviour. Techniques for measuring the electrical properties at different fiequencies are described. Possible application of the electrical properties to the measurement of the fractional water content of fresh concrete, the development of mechanical structure, and propagation calculations for the penetration of radar waveforms used in ground-probe radars, are discussed.
Fenning, P J; Jack, A G; Veness, J K
Ground probing radar applications in site investigation Non-destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. 2, pp 113-140. Edited by J H Bungey. The British Institute of NDT (1993) It is suggested that the introduction of ground probing radar systems which are based on proven seismic reflection methodology will overcome some of the misapplications of the past. Reference is made to the requirement for radar signal propagation velocity determination to be made on site and the pre-survey requirement of assessing theoretical ground radar applicability before commencing a radar survey. Examples of case histories are given. 52398
52132
Forde, M.C.; McCavitt, N.
Sonic NDT and r a d a r testing of masonry Non-Destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr. 1993. Vol. 2, pp. 489-505. Edited by J.H. Bungey. The British Institute of NDT (1993) The various methods of non-destructively testing masorLryare reviewed. The value of rotary coring and partially destructive investigation techniques are described in relation to the evaluation of masonry. The principles of digital sonic time domain testing, digital sonic frequency domain testing and digital time domain radar testing are explained and described in relation to applications to masonry bridges and retaining wall structures. From the case studies it is shown that the techniques of digital sonic impulse hammer testing and digital impulse radar testing are complementary in nature and can be used to cost effectively identify the geomeuies of masonry bridges in addition to fault detection, location.
Smale, D C
Impulse r a d a r - detail without destruction Non-destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. I, pp 97-111. Edited by J H Bungey. The British Institute of NDT (1993) Following a brief introduction covering the theoretical background to the Impulse Radar Method, the paper tackles the major problems with the technique in its current state of development and suggests possible ways forward in the resolution of these problems within the future.
52131 Broomfield, J.P.
The assessment of corrosion of reinforcing steel on highway bridges
52397 Hobbs, C P; Temple, J A G; Hillier, M J R a d a r inspection of civil engineering structures Non-destructive Testing in Chril Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. 1, pp 79-96. Edited by J H Bungey. The British Institute of NDT (1993) Despite the potential of radar, ~he civil engineering community in the UK has been slow to adopt the technology. This is partly because some claims about the capabilities of radar have been overstated, and also because the data currently generated can be difficult for the non- specialist to understand. Our work has used two approaches to address these specific problems. First, signal processing combined with a well-defined inspection procedure has been used to produce clearer images. Second, modelling of assumed subsurface structure is carried out to yield theoretical images which can be used to optimise inspections und aid in interpretation of real datafiles. The advantages over typical radar data are demonstrated by example. 52395
Non-Destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr. 1993. Vol. 2, pp. 551-566. Edited by J.H. Bungey. The British Institute of NDT (1993) This paper describes the results of a 31/2 year research program on non-destructive test techniques for measuring corrosion and corrosion damage on bridges. The work was done in the USA and was concerned with reinforced concrete bridge elements suffering from corrosion due to sea salt and deicing salt penetration. The research involved assessment of linear polarisation techniques for corrosion rate measurement and vehicle mounted radar techniques for measuring delaminations on bridge decks. Rapid field techniques for measuring the chloride content of concrete, the effectiveness of concrete sealers and waterproof membranes, and concrete permeability were also developed. An overall methodology of corrosion for reinforced concrete is discussed and a field evaluation of a bridge support slrueture in the UK is presented.
Ballard,G S
Non destructive assessment of pavement design and new build quality
51827
Non-destructive Testing in Civil Engineering, Liverpool, (United Kingdom), 14-16 Apr 1993. Vol. 1, pp 391-404. Edited by J H Bungey. The British Institute of NDT (1993) Pulsed Radio Echo Sounding (Ground Radar) is used to assess the structural composition of pavements and to provide information on thickness, bond and density for correlation with and correction of surface strength measurements. The construction of an experimental pavement, is examined: continuous assessment by radar shows wide deviation from the design specification, and faults of bond and compaction in the pavement itself, both in the experimental tapered sections and the standard parallel layer sections. The effect of these defects on apparent pavement strength and projected life is considered.
Decommissioning and Demolition 1992, Manchester (United Kingdom), 25-26 Mar. 1992. pp. 118-122. Edited by I.L. Whyte, Thomas Telford Ltd. (1992) This paper outlines new and sophisticated impulse digital nondestructive testing techniques. The techniques used include impulse digital time domain testing, impulse digital frequency domain testing and digital impulse radar testing. The techniques are described in relation to applications to concrete bridges. It is shown that the techniques of impulse sonic and radar testing are complementary in nature and can be used cost effectively to identify the geometries of structures in addition prior to decommissioning.
52361
Uomotor,T; Misra, S
Non destructive evaluation developments in J a p a n
of
RC
structures
Forde, M.C.; McCavitt, N.; Batchelor, AJ.
Evaluating structures using impulse r a d a r and sonic techniques
recent
Non-destructive Testing in Civil Engineering, Liverpool (United Kingdom), 14-16 Apr 1993. Vol. 1, pp 65-77. Edited by J H Bungey. The British Institute of NDT (1993) Although new NDT techniques are not well understood by concrete ungiueers, they are finding ways to apply such techniques as ultra sonic, acoustic emission, electro- magnetic technique, x-ray, thermograph, radar, etc, to evaluate crack distribution, crack depth, location and volume of large voids, location and size of reinforcements, degree of reinforcement corrosion, etc. This paper aims to introduce and discuss how NDT is being or going to be used in the field of concrete for civil engineering structures in Japan.
317
51357 Kratochvil, G.; Fenner, T.; Benson, R. SIR technology helps ensure safe landings for N A S A Materials Evaluation, Vol. 50, No. 12, pp. 1412-1414 (Dec. 1992) When a U.S. space shuttle lands, most often it touches down on an unpaved runway at Edwards Air Force Base in California's Mojave Desert. Its 190,000 pounds (86,184 kg) hit the natural lake-bed runway at 185 knots, placing tremendous stresses on the soil of the desert floor. Three times-once during a landing and twice as the shuttle was being towed from the lakebed landing strip to the edge of the lakebed-the wheels broke through the crust of the desert floor. To prevent danger to shuttle crews and damage to the spacecraft, NASA's shuttle program office instituted regular, programmed inspections of the landing strips in 1988. These investigations, managed by the Geologic Science Advisor, began as visual checks but now use a subsurface interface radar (SIR) system designed and manufactured by Geophysical Survey Systems, Inc., to ensure that the lake-bed runways will be free of unseen fissures and voids.