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Ultrasonic non-destructive testing for metals. by National Safety Council.(CARDINAL)141986;
Includes bibliographical references (page 6).
Subjects: Metals; Ultrasonic testing.;
Available copies: 1 / Total copies: 1
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Evaluation of a K.J. Law model 8300 ultrasonic roughness testing device / by McGhee, Kenneth H.(CARDINAL)314593; Virginia Transportation Research Council.(CARDINAL)195142;
Includes bibliographical references (page 15).Final report;A study of the K.J. Law Model 8300 Roughness Surveyor was begun in 1985 to determine the feasibility of replacing Mays Meter roughness testing equipment with an easier to use and more repeatable alternative. The original schedule called for completion of the study in late 1986. However, the study was badly delayed because of equipment failures, long delays by the manufacturer when the equipment was returned for trouble shooting, and altered priorities placed on the research staff. Because of these altered priorities, the study was tabled for several years so that final testing was not completed until mid-1991. It was found that, with certain limitations, the Surveyor (sn 1372) is capable of correlation with other roughness testing equipment and of providing test results meeting the requirements of HPMS Class II equipment. Among the major limitations are the following: (1) on coarse-textured surfaces, the device is highly sensitive to variations in testing speed, and (2) the device is highly sensitive to changes in ambient temperature. The author concludes that these limitations are too severe for the device to be used in any except very uncritical roughness testing.Sponsored by Virginia Department of Transportation, in cooperation with the U.S. Department of Transportation, Federal Highway Administration, under contract no.
Subjects: Technical reports.; Pavements; Road meters; Roads; Ultrasonic testing.;
Available copies: 1 / Total copies: 1
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Use of the impact-echo method in nondestructive measurements of the thickness of new concrete pavements / by Clemeña, G. G.(Gerardo G.)(CARDINAL)314479; Virginia Transportation Research Council.(CARDINAL)195142;
Includes bibliographical references (page 31).Final report;The nondestructive impact-echo (IE) method offers a simple means for introducing compressional stress waves into a concrete element or slab and measuring the resonance frequencies associated with the reflections of the waves from any internal voids and the bottom of the slab. It is relatively effective for detecting internal voids or delaminations in concrete, which is the application for which it was developed. It may also be possible to use the method for indirect measurement of the thickness of a slab if the wave propagation velocity in the concrete is known. This study was conducted to determine whether the IE method, by itself, could replace the use of coring for quality-assurance measurements of the thickness of concrete slabs in newly built pavements. The results from tests conducted on three pavements indicated that the wave velocity varied so much, not only between pavements but also within a pavement, that unacceptable errors can result when an average velocity is determined (through limited coring) for a pavement and subsequently assumed for the entire pavement. To reduce the error to an acceptable level, the wave velocity at any test location must be measured to within an acceptable accuracy by another independent method. In pursuit of this approach, an indirect-transmission procedure based on ultrasonic (UT) measurement was incorporated and tested. This combined IE/UT procedure was able to measure thickness with absolute errors of 5 mm in one pavement and 7 mm in another, at a 90% probability. These results can be considered encouraging since the current procedure requires that the length of a core reported to the nearest 3 mm be the average of several measurements around the core and, in some cores, these measurements can have a spread of as much as 13 mm. In addition, it is expected that these errors can be reduced easily with the use of a transducer with a smaller contact face that would be less sensitive to roughness on the surface of grooved concrete pavements.Sponsored by Virginia Department of Transportation, in cooperation with the Federal Highway Administration, under project no.
Subjects: Technical reports.; Pavements, Concrete; Pavements, Concrete; Ultrasonic testing.;
Available copies: 1 / Total copies: 1
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Railways 2011 : including 2011 Thomas B. Deen distinguished lecture. by National Research Council (U.S.).Transportation Research Board.(CARDINAL)141287;
Includes bibliographical references.Railroads and the new normal -- Assessment of wider economic impacts of high speed rail for Great Britain -- Economic impacts of intercity passenger rail service -- Cluster analysis of intercity rail passengers in emerging high speed rail corridor -- High speed railways in Spain -- Hierarchical network model of safe high speed rail operation -- Simplified approach for assessing initial fire development and spread in passenger rail vehicles -- Geometry of high speed turnouts -- International variation in cost benefit analysis of urban rail projects -- Influence of value of time on profitability of railway projects -- Expanding Alaska-Canada rail -- Midwest rail study -- Integrated optimization model to manage risk of transporting hazardous materials on railroad networks -- Train delay and economic impact of in-service failures of railroad rolling stock -- Basic tool kit for estimation of intermodal rail cost -- Noncontact ultrasonic guided-wave system for rail inspection -- Installation of railroad wayside defect detectors -- Track maintenance of heavy haul railways with resilient versus stiff fastenings -- Biobjective optimization model for maintenance and renewal decisions related to rail track geometry -- Verification of box test model and calibration of finite element model -- Analysis of derailments by accident cause.TRB Transportation Research Record: Journal of the Transportation Research Board, No. 2261 consists of 21 papers that explore the economic impacts of high speed rail and intercity passenger rail service, safe high speed rail operation, fire development and spread in passenger rail vehicles, geometry of high speed turnouts, and international variation in cost benefit analysis of urban rail projects. This issue of the TRR also examines the influence of value of time on profitability of railway projects, expanding Alaska Canada rail, near field impacts of emissions of fine particulate matter from rail yard activities, manage risk of transporting hazardous materials on railroad networks, and train delay and economic impact of in service failures of railroad rolling stock. In addition, this TRR also addresses the estimation of intermodal rail cost, noncontact ultrasonic guided wave system for rail inspection, installation of railroad wayside defect detectors, track maintenance of heavy haul railways, maintenance and renewal decisions related to rail track geometry, evaluation of railroad ballast performance, and analysis of derailments by accident cause.
Subjects: Technical reports.; Conference papers and proceedings.; Railroads.;
Available copies: 1 / Total copies: 1
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