Download or read book Nondestructive Evaluation of Deteriorated Prestressing Strands Using Magnetic Field Induction written by Bertrand Fernandes and published by . This book was released on 2010 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: A design, fabrication and proof of concept testing of a sensor system, based on magnetic field detection, to estimate the remaining cross sectional area in corroded prestressing strands was undertaken. Corrosion detection in prestressed concrete has been a challenging task since the most common way of doing it is by visual inspection. An electromagnet with Hall sensors was designed to estimate the cross sectional area of steel rods and prestressing strands of different diameters in a laboratory. The electromagnet induces a magnetic field in the steel bar/strand sample when magnetized from one side and at a distance from the magnet pole face. The induced magnetic field was found reliably proportional to the cross section area of the steel bar when magnetized near magnetic saturation, for a combination of various diameters, and distances of up to two inches from the pole face. The laboratory experiments were carried out using steel bars and prestressing strands with and without concrete cover. Magnetic field measurements of the corroded strand specimens are compared to those with sound ones. The effective remaining sound cross section area of the corroded specimen was then estimated, using the measurements of healthy specimens as a reference. The effective cross section area was correlated to different corrosion degrees. The effect of concrete on the magnetization process was analyzed. The results confirm that accurate measurement of the cross sectional area in a laboratory setting is possible with the proposed magnetic technique. The successful implementation of this sensor in nondestructive evaluation of bridges will be of great help for bridge condition assessment.
Download or read book Development of Induced Magnetic Field Procedure for Nondestructive Evaluation of Deteriorated Prestressing Strand written by Michael D. Titus and published by . This book was released on 2011 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The induced magnetic field (IMF) procedure for nondestructive evaluation of deteriorated prestressing strand predicts the sound cross-sectional area of strand in embedded concrete. The system utilizes an electromagnet that magnetizes the strand, and an array of hall sensors that measures Gauss readings that indicate the strength of the magnetic field of the strand. This technology allows bridge inspectors to go further than visual inspection when determining the condition of prestressed concrete beams. This thesis discusses the development of the IMF testing system, including both laboratory testing and a field test. During the course of this research, the magnetic flux leakage (MFL) testing procedure was also researched and utilized. The first documented field test of its kind was performed using magnetic inspection on a prestressed box beam bridge. The IMF system accurately predicted corrosion in a laboratory setting, and predicted corrosion during the field test, albeit with limited accuracy. The MFL method predicted corrosion more accurately in the field test.
Download or read book Magnetic Sensor for Nondestructive Evaluation of Deteriorated Prestressing Strand written by Douglas K. Nims and published by . This book was released on 2011 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report gives an account of the execution and achievements in Phase II of the project completed through August 2011. The main objective of this project is to advance the practical development of a nondestructive testing and evaluation method using the magnetic field technique to estimate corrosion in prestressing strands. The importance of developing such a method has been well established. Phase I and the literature review established the proof of concept for a magnetic inspection method. The magnetic technique of induced magnet field (IMF) was developed.
Download or read book Magnetic Sensor for Nondestructive Evaluation of Deteriorated Prestressing Strand written by James David Wade and published by . This book was released on 2010 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis was to develop a non-destructive in-situ magnetic technique to investigate the remaining cross-sectional area of prestressing strands. Corrosion is the predominate failure-mechanism in box-beam bridges. The current method, visual inspection, is not sufficient as the strands may not be exposed to the investigator. An inaccurate estimate of the remaining area of strands can lead to an overestimated strength of the bridge. A new technique involving an electromagnet and magnetic theories was researched for this thesis. The experiments conducted have shown that it is possible to distinguish between different cross-sectional areas using an electromagnet and Hall sensors. Experiments with an air-gap were first used to simulate concrete cover and provide viability of the technique. These experiments showed that as the cross-sectional area increased so did the induced magnetic field. To further the research, concrete blocks were used in place of the air-gap to better simulate field conditions. Again, these experiments showed an increase in the induced magnetic field as the cross-sectional area was increased. Using the data from the air-gap and concrete block experiments, an approach to determine the cross-sectional area of a corroded strand under concrete cover was investigated.
Download or read book Development of a Magnetic Field Sensor System for Nondestructive Evaluation of Reinforcing Steel in Prestressed Concrete Bridge Members written by Bertrand Fernandes and published by . This book was released on 2012 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nondestructive evaluation of prestressed concrete mainly includes inspection of the condition of the prestressing strands for load rating. This thesis presents a magnetic inspection system to measure main magnetic flux (MMF) and magnetic leakage flux (MFL) signals, to evaluate the condition of prestressing stands. A proof-of-concept has been established using a prototype electromagnet-sensor, showing a direct relationship between the cross-sectional area of the strand and the magnitude of magnetic field induced in it. A field test of a box-beam bridge was conducted using both MMF and MFL detection techniques separately. This led to the realization of a comprehensive MMF-MFL electromagnet-sensor system for inspection of prestressed steel in concrete. A computer aided simulation model was created to model the magnetic field signals and aid in better understanding of the electromagnet-sensor. This model is also useful for generating expected magnetic field signals from magnetization of different strand size and configuration setups and thus, helps in making corrosion estimations. The MMF-MFL signal detection concept was evaluated using the existing electromagnet-sensor in a laboratory setup and on prestressed box-beams obtained from a demolished bridge. It was able to identify corrosion and defects such as breaks or fractures in prestressing strands. For this magnetic inspection system to become practical, certain modifications such as redesign of the magnetic field generated by the magnet to have higher resolution have been suggested. Other features such as accurate measurement of pole face to strand distance and weight reduction have been discussed. The overall outcome of this research has shown that magnetic field signals can be useful to detect hidden corrosion in prestressed box-beams.
Download or read book Bridge Maintenance Safety Management Resilience and Sustainability written by Fabio Biondini and published by CRC Press. This book was released on 2012-06-21 with total page 4119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge Maintenance, Safety, Management, Resilience and Sustainability contains the lectures and papers presented at The Sixth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2012), held in Stresa, Lake Maggiore, Italy, 8-12 July, 2012. This volume consists of a book of extended abstracts (800 pp) Extensive collection of revised expert papers on recent advances in bridge maintenance, safety, management and life-cycle performance, representing a major contribution to the knowledge base of all areas of the field.
Download or read book Handbook on Nondestructive Testing of Concrete written by V. M. Malhotra and published by CRC Press. This book was released on 2004 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Civil engineers will value this resource that examines the tools and techniques used to estimate the in-place strength on concrete, permeation properties that relate to potential durability, and the methods used to assess the internal condition of concrete and the corrosion activity of steel reinforcement.
Download or read book Magnetic Flux Leakage Device for Evaluation of Prestressed Concrete Box Bridges written by Steve B. Chase and published by . This book was released on 2020 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Emission and Related Non destructive Evaluation Techniques in the Fracture Mechanics of Concrete written by Masayasu Ohtsu and published by Woodhead Publishing. This book was released on 2020-10-01 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic Emission and Related Non-destructive Evaluation Techniques in the Fracture Mechanics of Concrete: Fundamentals and Applications, Second Edition presents innovative Acoustic Emission (AE) and related non-destructive evaluation (NDE) techniques that are used for damage detection and inspection of aged and deteriorated concrete structures. This new edition includes multi-modal applications such as DIC, thermography, X-ray and in-situ implementations, all of which are helpful in better understanding feasibility and underlying challenges. This new edition is an essential resource for civil engineers, contractors working in construction, and materials scientists working both in industry and academia. - Completely updated, with a new chapter on multi-technique damage monitoring - Presents new applications and novel technologies on AE and related NDT in the fracture mechanics of concrete - Features contributions from recognized world-leaders in the application of acoustic emission (AE) and NDE techniques used for the damage assessment of concrete and concrete structures
Download or read book Public Roads written by and published by . This book was released on 1997 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Evaluation of Highways Utilities and Pipelines written by and published by . This book was released on 2000 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Evaluation of Highways Utilities and Pipelines IV written by A. E. Aktan and published by SPIE-International Society for Optical Engineering. This book was released on 2000 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Evaluation written by and published by . This book was released on 1994 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detecting Defects and Deterioration in Highway Structures written by David G. Manning and published by Transportation Research Board National Research. This book was released on 1985 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need to detect defects and deterioration in highway structures ranges from reasons of safety to the prediction of load capacity to the information base for a bridge manangement system. The emphasis here is on test procedures that can be used in the field and guidance is given in interpreting the significance of measured values. Although it is usually possible to detect deterioration in a component of a structure, it is often difficult to assess the effect of the deterioration on the load-carrying capacity of the structure. Often, full scale testing is justified to measure the overall condition of a structure. A survey of current practices revealed that concrete structures are being tested more extensively than steel or timber structures.
Download or read book Challenges in Corrosion written by V. S. Sastri and published by John Wiley & Sons. This book was released on 2015-07-07 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides detailed methods to reduce or eliminate damage caused by corrosion Explains the human and environmental costs of corrosion Explains causes of and various types of corrosion Summarizes the costs of corrosion in different industries, including bridges, mining, petroleum refining, chemical, petrochemical, and pharmaceutical, pulp and paper, agricultural, food processing, electronics, home appliances etc Discusses the technical aspects of the various methods available to detect, prevent, and control corrosion
Download or read book Durability of Prestressed Concrete Highway Structures written by David G. Manning and published by Transportation Research Board National Research. This book was released on 1988 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis will be of interest to bridge designers, materials engineers, maintenance engineers, and others concerned with the durability of prestressed concrete bridges. Information is presented on the factors affecting the durability of prestressed concrete. Prestressed concrete bridges require special attention because the capacity of the structure is strongly dependent on the prestressing force. This report of the Transportation Research Board reviews the factors affecting the durability of prestressed bridge components and describes methods of detecting and assessing deterioration, preventive maintenance, repair, and methods of improving durability in new structures.
Download or read book Synthesis of Highway Practice written by National Cooperative Highway Research Program and published by . This book was released on 1988 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt:
