EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Acoustic Emission Sensing for Crack Monitoring in Prefabricated and Prestressed Reinforced Concrete Bridge Girders

Download or read book Acoustic Emission Sensing for Crack Monitoring in Prefabricated and Prestressed Reinforced Concrete Bridge Girders written by Robert Lee Worley (II) and published by . This book was released on 2019 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prefabricated and pre-stressed reinforced concrete beams and girders are integral components of many highway structures, including those built by rapid construction techniques. Concerns exist regarding the development of cracks during curing, form removal, detensioning, transport, installation, and operation. Non-destructive, Acoustic Emission (AE) sensing techniques have the potential for detecting and locating cracking in prefabricated, pre-stressed concrete girders used as Prefabricated Bridge Elements and Systems (PBES) used in rapid construction practices as part of a Quality Assurance/Quality Control (QA/QC) program. AE sensing records transient elastic waves produced by the release of stored elastic energy resulting in plastic deformations (i.e., crack nucleation and growth) with an array of point sensors. The AE instrument system is relatively portable which can allow for it to be an option for both off-site fabrication QA/QC as well as on-site field QA/QC. This thesis presents a multi-stage research initiative on acoustic emission monitoring of prefabricated and pre-stressed reinforced concrete beams used in highway bridge construction during detensioning, craned removal from formwork and transport to bridge sites, along with supporting laboratory tests and numerical analysis. The specific objectives of this research were to: 1. Identify suitable instruments to monitor pre-stressed and/or post-tensioned concrete girders for cracking activity; 2. Design and develop a reusable instrumentation package; 3. Measure performance and condition of concrete girders during fabrication and transport; and 4. Identify test protocols and possible accept/fix/reject criteria for structural elements based on information from monitoring system. Presented are results from laboratory, full-scale girder fabrication, and transport monitoring, along with overall conclusions and recommendations for future research.

Book Investigation of Crack Propagation During a Load Test on a Prestressed Concrete Bridge Using Acoustic Emission Sensors and Strain Transducers

Download or read book Investigation of Crack Propagation During a Load Test on a Prestressed Concrete Bridge Using Acoustic Emission Sensors and Strain Transducers written by Abram Mason Lane and published by . This book was released on 2018 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge 9130 is a three span continuous prestressed concrete bulb-tee girder bridge carrying two eastbound lanes of U.S. highway 60 near Vaughn, New Mexico. Shortly after construction in 2002, cracking was recorded on all girder ends at both abutments. Approximately 10 years later, epoxy injection was applied to these cracks but was only partially effective at arresting the cracks. Research was undertaken by New Mexico State University to investigate continued crack propagation using non-destructive testing methods including acoustic emission sensors and strain transducers during a load test. Ten load paths were used for the load test with up to two trucks on the bridge at a time. The critical load path, or the load path in which the greatest strains were seen, was identified using data analysis from the strain transducers. Data analysis including intensity analysis, wave speed and source location, and cumulative signal strength plots were performed on the data obtained from the acoustic emissions sensors. Moment and shear forces were calculated from the strain transducer data. Both analyses were then compared with one another to prove evidence of crack propagation. Additionally, software modeling of permit overloads that had crossed Bridge 9130 was done to compare the moment forces caused by the test trucks to the moments caused by the overloads to determine if cracking was occurring due to these overloads. The analytical and experimental distribution factors for moment were computed and compared with the distribution factors calculated from AASHTO guidelines. The theoretical neutral axis calculated and compared to the experimental neutral axis to identify if composite action was occurring in the structure. This research found the data collected by both the acoustic emission sensors and the strain transducers successfully correlated with one another to prove that crack propagation likely occurred under test truck loading. Based on the amount of data seen during single and two truck loading, cracking would likely have occurred due to the permit overloads. Composite action was seen during the load test, and the analytical and AASHTO distribution factors were more conservative than the experimental distribution factors.

Book Proceedings of the Canadian Society of Civil Engineering Annual Conference 2021

Download or read book Proceedings of the Canadian Society of Civil Engineering Annual Conference 2021 written by Scott Walbridge and published by Springer Nature. This book was released on 2022-04-13 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises the proceedings of the Annual Conference of the Canadian Society of Civil Engineering 2021. The contents of this volume focus on specialty conferences in construction, environmental, hydrotechnical, materials, structures, transportation engineering, etc. This volume will prove a valuable resource for those in academia and industry.

Book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Girders

Download or read book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Girders written by Jay Andrew McKeefry and published by . This book was released on 1999 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Girders

Download or read book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Girders written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Structures

Download or read book Acoustic Emission Monitoring of Fatigue Cracks in Steel Bridge Structures written by Jay McKeefry and published by . This book was released on 1999 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents results from a laboratory study and field implementation of acoustic emission monitoring or fatigue cracks in cover-plated steel bridge girders. The acoustic monitoring successfully detected growing fatigue cracks in the lab when using both source location and a state of stress criteria. Application of this methodology on 3 field bridges also proved successful by detecting a propagating crack in 2 of the bridges and an extinguished crack in a third bridge.

Book Advanced Materials and Techniques for Structural Monitoring Analysis and Control

Download or read book Advanced Materials and Techniques for Structural Monitoring Analysis and Control written by Chun-Xu Qu and published by Frontiers Media SA. This book was released on 2024-06-18 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Assessing the service status and maintaining the safety of existing structures are critical to the sustainable operations of various engineering and cross-industry, including civil infrastructures, railways and machinery. Static and dynamic structural characteristics play a key role in the global deterioration assessment of the structural performance, which has enabled structural monitoring and analysis technology to become an active focus in the engineering area. Meanwhile, structural control has been widely used in modern structural engineering. Structural control devices are implemented to enhance deteriorating structures and mitigate natural disasters. Through advanced structural control technology, the structural responses can be controlled. These structural control techniques include passive, active or semi-active reverse forces, which aim to modify structural stiffness, mass and damping with minimal control force. Structural control, monitoring and analysis complement each other, ensuring the safety of the structure to the greatest extent.

Book Development of Acoustic Emissions Testing Procedures Applicable to Conventionally Reinforced Concrete Deck Girder Bridges Subjected to Diagonal Tension Cracking

Download or read book Development of Acoustic Emissions Testing Procedures Applicable to Conventionally Reinforced Concrete Deck Girder Bridges Subjected to Diagonal Tension Cracking written by Steven C. Lovejoy and published by . This book was released on 2006 with total page 1068 pages. Available in PDF, EPUB and Kindle. Book excerpt: A need exists to develop a non-destructive testing technique that can identify the formation and propagation of diagonal tension cracks in conventionally steel reinforced concrete deck girder (RCDG) highway bridges in the State of Oregon. Such a technique could be included into a structural health monitoring (SHM) system installed on specific bridges to automatically monitor the current state of structural damage in primary load supporting elements and provide notification of recent damage to bridge engineers in nearly real time. This research investigates the practical application of AE used to supplement a conventional SHM on vintage RCDG bridges. Background work presented in the Appendices investigates stress wave propagation in non-reinforced and steel reinforced concrete media. Based on the characterization of stress wave speeds, amplitude attenuation, frequency content and wave forms found in concrete media, testing methods are developed and applied to 31 full sized RCDG test specimens that include variations in loading, load capacity and structural detailing. Several different AE test procedures are used to characterize the damage states of the test beams as they are progressively loaded to failure. Four previously developed AE parameters that characterize both damage progression and damage state are applied which include the Felicity and Calm Ratios, Severity and the Historic Index. Both Felicity and Calm Ratios were found to respond to the damage state of the test beam as determined from more conventional assessment methods such as crack width and load. For the practical in-service loading ranges of 20 to 80% of ultimate capacity both the Felicity and Calm Ratios were found to respond in a nearly linear manner with increasing damage. Three categories of damage state are defined which are based on the ODOT crack comparator tool which is used for in-service maintenance inspections of these bridges. Felicity and Calm Ratio values are related to these damage states for the specific type of bridge girders being tested and can be used to estimate in-service damage states. The Severity and Historic Index responses were found to be an effective means of identifying the formation and extension of diagonal tension cracks as they developed. Threshold levels for these two parameters are identified for specific AE sensor types when applied to this class of bridge girder. A preliminary set of AE testing and analysis procedures were developed that were applied to three in-service bridges. These bridge tests used both controlled and ambient loading protocols. The structural response to each load case was quantified by using both crack width motion and reinforcing steel strain range. These structural parameters were correlated with the AE data. The Calm Ratio was found to be of practical importance and that the values recorded were in reasonably good agreement with the laboratory data once the imposed loads and current crack widths were considered. The Severity and Historic Index were also found to be of practical importance to bridge testing and structural health monitoring as they were found to be very sensitive to increasing damage, yet exhibit good stability provided enough AE activity was present. A recommend set of guidelines and practices for applying AE to vintage RCDG bridges is developed and presented.

Book Proceedings of The 17th East Asian Pacific Conference on Structural Engineering and Construction 2022

Download or read book Proceedings of The 17th East Asian Pacific Conference on Structural Engineering and Construction 2022 written by Guoqing Geng and published by Springer Nature. This book was released on 2023-03-13 with total page 1545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents articles from The 17th East Asian-Pacific Conference on Structural Engineering and Construction, 2022, organized by National University of Singapore. These peer-reviewed articles, authored by professional engineers, academics and researchers, highlight the recent research and developments in structural engineering and construction, embracing the theme- “Towards a Resilient and Sustainable City”. The papers presented in this proceeding provide in-depth discussions with key insights into the future research, development and engineering translation in structural engineering and construction.

Book Instability Mechanism and Disaster Prevention of the Jointed Rockmass

Download or read book Instability Mechanism and Disaster Prevention of the Jointed Rockmass written by Shuren Wang and published by Frontiers Media SA. This book was released on 2024-06-13 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discontinuities such as cracks, fissures, bedding planes, etc. resulting from different geological processes are commonly found in rock masses and often play a critical role in the initiation, propagation, and coalescence of new cracks due to stress redistribution caused by engineering activities and natural disturbances. It is challenging to determine the instability mechanism of jointed rock masses but it is vital for estimating instability disasters in jointed rock engineering.

Book Acoustic Emission Testing of In service Conventionally Reinforced Concrete Deck Girder Superstructures on Highway Bridges

Download or read book Acoustic Emission Testing of In service Conventionally Reinforced Concrete Deck Girder Superstructures on Highway Bridges written by Steven C. Lovejoy and published by . This book was released on 2008 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three reports were produced from research sponsored by the Oregon Department of Transportation on acoustic emission (AE). The first describes the evaluation of AE techniques applied to two reinforced concrete (RC) bridge girders, which were loaded to mimic in-service conditions. The main goal was to get a thorough understanding of how AE methods can be used with RC and in what way these methods can assist in maintaining the states aging RC deck girder bridges. Recommended settings for data acquisition and processing were evaluated. In addition to the complex full-scale beam components, studies were performed on smaller test specimens that improved understanding of stress wave propagation through reinforced concrete and the response of acoustic emission sensors in detecting these waves. Some qualitative and quantitative assessment methodologies were described, and examples and limitations of the methods were presented. Source locations in three dimensions were performed, and strategies on how to best deploy sensors were evaluated using Monte Carlo Simulations.