Download or read book The Interpretation of Ultrasonic Wave Signals Received from Concrete Bridge Decks with Simulated Cracks Using Ultrasonic Pulse Velocity Technique written by Liz Jean Zea Garavito and published by . This book was released on 1997 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Master s Theses Directories written by and published by . This book was released on 2000 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Education, arts and social sciences, natural and technical sciences in the United States and Canada".
Download or read book Technologies for Improving the Evaluation and Repair of Concrete Bridge Decks written by and published by . This book was released on 1998 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detection of Multiple Flaws in Concrete Bridge Decks Using Ultrasonic Wave Propagation written by and published by . This book was released on 2018 with total page 54 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 1996 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Injection ultrasonic Pulse echo PORT UPE System for Concrete Bridge Deck Repair written by University of Nebraska--Lincoln. Center for Infrastructure Research and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact echo written by Mary Sansalone and published by . This book was released on 1997 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Artificial Neural Networks to Ultrasonic Pulse Echo System for Detecting Microcracks in Concrete written by A. Michael Alexander and published by Washington, DC : U.S. Army Corps of Engineers. This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete deterioration standards containing various levels of microcracks were engineered by adding calcium sulfate to the concrete mixture and curing under moisture at 38 deg. C (100 deg. F). The level of the mircocracks was classified according to the speed of the ultrasonic pulse velocity (UPV) through the specimens using the American Society for Testing and Material (ASTM) C 597 (ASTM 1994c) test method and was found to vary uniformly from 1,737 to 4,877 m/sec (5,700 to 16,000 ft/sec). After receiving some preprocessing, 186 ultrasonic pulse echo (UPE) signals were used as input training examples for the artificial neural network (ANN) system. Target values for the ANN were the measured UPVs as determined form the ASTM C 597 test method. The correlation coefficient from a least squares fit was 98.6 percent. After training, the ANN was performance tested with 30 UPE signals that the model had not seen in training. A least squares fit demonstrated that the output velocities from the ANN correlated well with the measured (target) UPVs. The correlation coefficient was 84.8 percent. The system was able to rank all six specimens in the correct order of deterioration. This investigation demonstrates that the automated interpretation of UPE signals for continuous interfaces by the ANN is feasible.
Download or read book Application of Seismic Surface waves in Concrete Bridge deck Evaluation written by Farhad Fetrat and published by . This book was released on 2016 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate and timely condition assessment of bridge decks is essential for economic management of aging highway bridges. The ability to evaluate concrete modulus profile in a bridge deck can help the detection of early signs of deterioration and optimize the bridge maintenance procedures. This study presents a new method for modulus profiling of concrete bridge decks. The stiffness matrix method is used to simulate wave propagation in a layered media. The results are compared to numerical finite element models. Dispersion analysis is done using the multi-channel analysis of surface waves (MASW) and phase-shift methods. The characteristics of dispersion surface are analyzed and the effects of model parameters on dispersion surface are examined through a series of parametric studies. An inversion technique is proposed for a fast inversion of surface-wave data collected on bridge decks. This technique utilizes a database of pre-calculated dispersion surfaces and takes advantage of the observed patterns in the parametric study as a priori information for the inversion process.
Download or read book Technologies for Improving the Evaluation and Repair of Concrete Bridge Decks Ultrasonic Pulse Echo and Polymer Injection written by Michel Alexander and published by . This book was released on 1998 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: A significant number of concrete bridge decks, both public- and nonpublic use, in the United States are subjected to a variety of detrimental environmental conditions. Many of the decks are in northern regions and are subject to cold weather; some of these are subjected to further degradation from the applications of deicing salts. The current major distress noted is the occurrence of shallow delaminations resulting in horizontal voids below the surface of the decks. It appears the majority of the delaminations are caused by freezing and thawing action, by chloride attack that corrodes the reinforcement, and by alkali-silica reaction. All three attack mechanisms require the presence of moisture. Efforts to design and place a dense, impermeable concrete are hindered at times due to the porous nature of concrete. As the concrete ages, a micro system of tension cracks and other surface imperfections can develop, exposing the matrix to water and chloride infiltration. Water infiltration alone can lead to accelerated alkali-silica reaction and steel-reinforcement corrosion. Surface spalling not only reduces ride quality, but it leads to more serious problems including structural deterioration and failure. Many concrete sealers and penetrants on the market are designed to protect concrete by improving and enhancing its physical properties. Surface sealers such as silane, silicones, and siloxanes have been developed to prevent the infiltration of moisture and chlorides. Penetrants such as high molecular weight methacrylate (HMWM) and epoxies have been developed to penetrate and fill cracks and porous areas in the concrete, sealing it against the infiltration of air, water, and chloride. Once the concrete is effectively sealed, both the progression of alkali-silica reaction and the corrosion of the reinforcing steel are arrested. These materials are also designed to bond to the concrete and thus to the structural integrity of the concrete.
Download or read book Effects of Traffic induced Vibrations on Bridge deck Repairs written by David G. Manning and published by Transportation Research Board National Research. This book was released on 1981 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This synthesis will be of special interest to engineers concerned with placements of concrete for construction or repair of bridge decks. Recommendations are provided for restoring, patching, and widening bridge decks in the presence of traffic."--Avant-propos.
Download or read book Detection of Flaws in Asphalt Overlaid Concrete Bridge Decks Using Ultrasonic Guided Waves written by Ece Erdogmus and published by . This book was released on 2020 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Continuous Long term Health Monitoring Using Ultrasonic Wave Propagation written by Ece Erdogmus and published by . This book was released on 2016 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report presents the findings of a research project on using ultrasonic testing to continuously monitor reinforced concrete bridge decks for the onset of delamination. The report first presents a review of current nondestructive testing techniques used in practice and research, and deficiencies of these methods. Then the novel method developed in this project to identify early delamination in reinforced concrete bridge decks is presented. This method uses a unique sensor setup compared to current ultrasonic testing methods and utilizes the waves leak into the concrete from the rebar that is excited with ultrasonic waves" (page 9).
Download or read book Effectiveness of Ultrasonic Pulse Velocity and Impact echo Ndt Techniques to Assess the Quality of Concrete written by Shibli Russel Mohiuddin Khan and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The deterioration of concrete in structure is a result of several internal or external degradation mechanism and which results in distress of the structure i.e. decrease in strength and integrity of the structure. the state of distress is often hidden from view and is only evident at a stage where there is significant reduction in strength of the structure. defects are open introduced during construction and are viewed during in services life. Some deterioration is viewed physically in the early age or during the services life of the structure in terms of spalling, surface crack, swelling and honeycombing. This deterioration collectively or individually results in reducing the load carrying capacity in terms of the distress of the structure. In this project, the common defects in the concrete structures and mapping techniques by nondestructive test are presented. Among the various techniques of the nondestructived tests, the Ultrasonic Pulse Velocity (UPV) and DOCtor's impact echo were chosen for their effectiveness. The UPV is used to estimate the concrete strength, detecting flaws such as voids and cracks and also to investigate the effects of smaller diameter bar in the concrete. In detecting various sizea of voids by the Impact-echo test techiniques a format was suggested to identify the from the frequency spectrum. In the bridge condition assessment by nondestructive test techniques most common problem encountered were correlationof cube crushing strength to the UPV values, in order to determine residual strength of the structure in different enviromental conditions. also the other defects such as cracks and voids in the concrete, which does not have any standard guideline to identify them by theabove NDT techniques to use in the bridge condition assessment. This project has dealt with large number of specimens between the actual condition and those of the values given by the NDT results. A number of beam specimens were also cast with known defects in the concrete in order to obtain and suggest standard investigation procedure. 108 standard cubes with different grades and enviromental conditions were cast. Also eight beams and a slab were casting having known common defects. From the strength- UPV correlation nine numbers of regression equations were suggested. A standard transducer spacing has been suggested for detecting crack depth of to 50 to 125mm range. The effect of bar sizes on UPV test results was also obtained. Reinforced concrete slabs or decks having bar diameter greater than 10mm diameter will be affect the reading of UPV. Based on the obtained resuls a computer database system for NDT has been made to accomodate and fulfill necessary requirements of knowledge base system. Hence this knowledge base system will be used for bridge condition assessment.
Download or read book Finite Element Assessment of Cracks and Delaminations in Concrete Bridge Decks by the Impact echo Method written by Yiping Geng and published by . This book was released on 1992 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Air coupled Impact echo Test Method written by Jeramy C. Ashlock and published by . This book was released on 2015 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Applicability of Acoustic Pulse Velocity Measurements to the Evaluation of the Quality of Concrete in Bridge Decks written by Gilbert Swift and published by . This book was released on 1971 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
