Most of the moveable bridges use open grid steel decks, because these are factory assembled, light-weight, and easy to install. Open grid steel decks, however, are not as skid resistant as solid decks. Costly maintenance, high noise levels, poor riding comfort and susceptibility to vibrations are among the other disadvantages of these decks. The major objective of this research was to develop alternative deck systems which weigh no more than 25 lb/ft2, have solid riding surface, are no more than 4-5 in. thick and are able to withstand prescribed loading. Three deck systems were considered in this study: ultra-high performance concrete (UHPC) deck, aluminum deck and UHPC-fiber reinforced polymer (FRP) tube deck. UHPC deck was the first alternative system developed as a part of this project. Due to its ultra high strength, this type of concrete results in thinner sections, which helps satisfy the strict self-weight limit. A comprehensive experimental and analytical evaluation of the system was carried out to establish its suitability. Both single and multi-unit specimens with one or two spans were tested for static and dynamic loading. Finite element models were developed to predict the deck behavior. The study led to the conclusion that the UHPC bridge deck is a feasible alternative to open grid steel deck. Aluminum deck was the second alternative system studied in this project. A detailed experimental and analytical evaluation of the system was carried out. The experimental work included static and dynamic loading on the deck panels and connections. Analytical work included detailed finite element modeling. Based on the in-depth experimental and analytical evaluations, it was concluded that aluminum deck was a suitable alternative to open grid steel decks and is ready for implementation. UHPC-FRP tube deck was the third system developed in this research. Prestressed hollow core decks are commonly used, but the proposed type of steel-free deck is quite novel. Preliminary experimental evaluations of two simple-span specimens, one with uniform section and the other with tapered section were carried out. The system was shown to have good promise to replace the conventional open grid decks. Additional work, however, is needed before the system is recommended for field application.

The objectives of this research were to 1) investigate bridge deck condition assessment methods used in the field and laboratory, methods of managing bridge decks, and methods for estimating remaining bridge deck service life using computer models through a comprehensive literature review on these subjects; 2) collect and analyze field data from representative concrete bridge decks in Utah; and 3) develop a decision tree for concrete bridge deck management in Utah. As a result of the literature review performed for objective 1, a synthesis of existing information about condition assessment, bridge deck preservation and rehabilitation, bridge deck reconstruction, and estimating remaining service life using computer models was compiled. For objective 2, 15 bridge decks were strategically selected for testing in this research. Five bridge decks had bare concrete surfaces, five bridge decks had asphalt overlays, and five bridge decks had polymer overlays. Bridge deck testing included site layout, cover depth measurement, chloride concentration testing, chain dragging, half-cell potential testing, Schmidt rebound hammer testing, impact-echo testing, and vertical electrical impedance testing. Two-sample t-tests were performed to investigate the effects of selected bridge deck features, including polymer overlay application, deck age at polymer overlay application, overlay age, asphalt overlay application with and without a membrane, stay-in-place metal forms (SIPMFs), SIPMF removal, internally cured concrete, and use of an automatic deck deicing system. For objective 3, condition assessment methods were described in terms of test type, factors evaluated, equipment cost, data collection speed, required expertise, and traffic control for each method. Unit costs, expected treatment service life estimates, and factors addressed for the preservation, rehabilitation, and reconstruction methods most commonly used by the Utah Department of Transportation (UDOT) were also summarized. Bridge deck testing results were supplemented with information about current bridge deck management practices and treatment costs obtained from UDOT, as well as information about condition assessment and expected treatment service life, to develop a decision tree for concrete bridge deck management. Based on the results of field work and statistical analyses, placing an overlay within a year after construction is recommended. Removing SIPMFs after a deck age greater than 18 years is not likely to be effective at reversing the adverse effects of the SIPMFs on bridge deck condition and is not recommended. Bridge deck construction using internally cured concrete is not recommended for protecting against rebar corrosion. To the extent that excluding an automatic deck deicing system does not compromise public safety, automatic deck deicing systems are not recommended. To supplement the typical corrosion initiation threshold of 2.0 lb Cl-/yd3 of concrete for black bar, a corrosion initiation threshold of 8.0 lb Cl-/yd3 of concrete is recommended in this research for bridge decks with intact epoxy-coated rebar. For chloride concentrations less than 20 lb Cl-/yd3 of concrete as measured between reinforcing bars, an increase of up to 70 percent should be applied to estimate the corresponding chloride concentration of the concrete in direct contact with the rebar. The decision tree developed in this research includes 10 junctions and seven recommended treatments. The junctions require the user to address questions about surface type, degree of protection against water and chloride ion ingress, degree of deterioration, and years of additional service life needed; the answers lead to selection of treatment options ranging from repairing an overlay to full-depth bridge deck reconstruction. Revisions to the decision tree should be incorporated as additional methods, data, treatments, or other relevant information become available.

The objectives of this research were to 1) investigate bridge deck condition assessment methods used in the field and laboratory, methods of managing bridge decks, and methods for estimating remaining bridge deck service life using computer models through a comprehensive literature review on these subjects; 2) collect and analyze field data from representative concrete bridge decks in Utah; and 3) develop a decision tree for concrete bridge deck management in Utah. As a result of the literature review performed for objective 1, a synthesis of existing information about condition assessment, bridge deck preservation and rehabilitation, bridge deck reconstruction, and estimating remaining service life using computer models was compiled. For objective 2, 15 bridge decks were strategically selected for testing in this research. Five bridge decks had bare concrete surfaces, five bridge decks had asphalt overlays, and five bridge decks had polymer overlays. Bridge deck testing included site layout, cover depth measurement, chloride concentration testing, chain dragging, half-cell potential testing, Schmidt rebound hammer testing, impact-echo testing, and vertical electrical impedance testing. Two-sample t-tests were performed to investigate the effects of selected bridge deck features, including polymer overlay application, deck age at polymer overlay application, overlay age, asphalt overlay application with and without a membrane, stay-in-place metal forms (SIPMFs), SIPMF removal, internally cured concrete, and use of an automatic deck deicing system. For objective 3, condition assessment methods were described in terms of test type, factors evaluated, equipment cost, data collection speed, required expertise, and traffic control for each method. Unit costs, expected treatment service life estimates, and factors addressed for the preservation, rehabilitation, and reconstruction methods most commonly used by the Utah Department of Transportation (UDOT) were also summarized. Bridge deck testing results were supplemented with information about current bridge deck management practices and treatment costs obtained from UDOT, as well as information about condition assessment and expected treatment service life, to develop a decision tree for concrete bridge deck management. Based on the results of field work and statistical analyses, placing an overlay within a year after construction is recommended. Removing SIPMFs after a deck age greater than 18 years is not likely to be effective at reversing the adverse effects of the SIPMFs on bridge deck condition and is not recommended. Bridge deck construction using internally cured concrete is not recommended for protecting against rebar corrosion. To the extent that excluding an automatic deck deicing system does not compromise public safety, automatic deck deicing systems are not recommended. To supplement the typical corrosion initiation threshold of 2.0 lb Cl-/yd3 of concrete for black bar, a corrosion initiation threshold of 8.0 lb Cl-/yd3 of concrete is recommended in this research for bridge decks with intact epoxy-coated rebar. For chloride concentrations less than 20 lb Cl-/yd3 of concrete as measured between reinforcing bars, an increase of up to 70 percent should be applied to estimate the corresponding chloride concentration of the concrete in direct contact with the rebar. The decision tree developed in this research includes 10 junctions and seven recommended treatments. The junctions require the user to address questions about surface type, degree of protection against water and chloride ion ingress, degree of deterioration, and years of additional service life needed; the answers lead to selection of treatment options ranging from repairing an overlay to full-depth bridge deck reconstruction. Revisions to the decision tree should be incorporated as additional methods, data, treatments, or other relevant information become available.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18653号 / 工博第3962号 / 新制||工||1610(附属図書館) / 31567 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 杉浦 邦征, 教授 白土 博通, 教授 河野 広隆 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Three series of tests were conducted on a sandwich plate bridge deck, which consisted of two steel plates and an elastomer core. The first series of testing was conducted by applying a static load on a full scale sandwich plate bridge deck panel. Local strains and deflections were measured to determine the panel's behavior under two loading conditions. Next, fatigue tests were performed on the longitudinal weld between two sandwich plate panels. Two connections were tested to 10 million cycles, one connection was tested to 5 million cycles, and one connection was tested to 100,000 cycles. The fatigue class of the weld was determined and an S-N curve was created for the longitudinal weld group. Finally, a series of experiments was performed on a half scale continuous bridge deck specimen. The maximum positive and negative flexural bending moments were calculated and the torsional properties were examined. Finite element models were created for every load case in a given test series to predict local strains and deflections. All finite element analyses were preformed by Intelligent Engineering, Ltd. A comparison of measured values and analytical values was preformed for each test series. Most measured values were within five to ten percent of the predicted values. Shear lag in the half scale bridge was studied, and an effective width to be used for design purposes was determined. The effective width of the half scale simple span sandwich plate bridge deck was determined to be the physical width. Finally, supplemental research is recommended and conclusions are drawn. / Master of Science

Twenty cantilever diaphragm tests were performed in the Structures and Materials Laboratory at Virginia Tech. The tests included both deep deck and cellular deck profiles with varying structural and side-lap connections. The tests were conducted with three different structural connections: screws, pins and welds and two different side-lap connections: screws and button punch. The tests were conducted and both load and deflection of the diaphragms were recorded. The current International Code Council, ICC, evaluation procedure shows that there are two different methods for measuring diaphragm deflection. The first method was by measuring specific corner displacements and making corrections to remove any rigid body motion. The second method is by measuring the deflection of the diagonals of the diaphragm. In this study both measurements were taken to do a comparison of the results that were obtained. Both strength and stiffness values were calculated based on the Steel Deck Institute (SDI) Diaphragm Design Manual (2004) and modifications described by Luttrell (2005). The paper by Luttrell (2005) only recommends modifications for the calculation of diaphragm stiffness. The data obtained from the tests were compared to the SDI calculations to distinguish any noticeable trends. Modifications are recommended regarding diaphragm strength and further research is suggested to create a better stiffness prediction of diaphragms. / Master of Science

The Texas Department of Transportation (TxDOT) uses precast, prestressed concrete panels (PCPs) as stay-in-place formwork for most bridges built in Texas. The PCPs are placed on the top flanges of adjacent girders and topped with a 4-in. cast-in-place (CIP) slab. This thesis is directed towards identifying and quantifying the serviceability implications of reducing the deck reinforcement across the interior spans of CIP-PCP decks. The goal of this research is to understand how the PCPs influence cracking and crack control in the CIP slab and to make recommendations to optimize the top mat reinforcement accordingly. Several tests were conducted to evaluate the performance of different top mat reinforcement arrangements for ability to control crack widths across PCP joints. The longitudinal reinforcement was tested using a constant bending moment test, a point load test, and several direct tension tests. Because of difficulty with the CIP-PCP interface during the longitudinal tests, direct tension tests of the CIP slab only were used to compare the transverse reinforcement alternatives. Prior to testing, various top mat design alternatives were evaluated through pre-test calculations for crack widths. Standard reinforcing bars and welded wire reinforcement were considered for the design alternatives. During this study, it was found that the tensile strength of the CIP slab is critical to controlling transverse crack widths. The CIP-PCP interface is difficult to simulate in the laboratory because of inherent eccentricities that result from the test specimen geometry and loading conditions. Furthermore, the constraint and boundary conditions of CIP-PCP bridge decks are difficult to simulate in the laboratory. Based on the results of this testing program, it seems imprudent to reduce the longitudinal reinforcement across the interior spans of CIP-PCP decks. The transverse reinforcement, however, may be reduced using welded wire reinforcement across the interior spans of CIP-PCP decks without compromising longitudinal crack width control. A reduced standard reinforcing bar option may also be considered, but a slight increase in longitudinal crack widths should be expected. / text

O presente trabalho se propôs a estudar os esquemas estruturais alternativos para pontes esconsas e avaliar as modelagens matemáticas possíveis através de softwares especializados, como o SAP2000 e STRAP2010, a fim de identificar as melhores soluções e modelos para cada caso. O objetivo foi o de aprimorar os modelos de cálculo, especialmente no que diz respeito à previsão das reações de apoio e das forças cortantes, ponto mais delicado de obras esconsas. O estudo baseou-se em soluções de superestrutura em laje e em grelha, com ou sem transversinas, com esconsidade variável entre zero e sessenta graus, eixo longitudinal reto, modeladas por barras e elementos finitos. Não foi objeto deste estudo a influência da meso e da infraestrutura dessas pontes nos esforços na superestrutura. / The present work is proposed to study alternative structural schemes for skew bridges and to evaluate possible mathematical modeling through specialized software, such as SAP 2000 and STRAP2010, in order to identify the best solutions and models for each case. The aim was to improve the calculation models, especially with regard to the prediction of the support reactions and shear forces, most delicate point in skew bridges. The study was based on slab or grid, with or without transversal beams, superstructure solutions, with variable skew between zero and sixty degrees, straight longitudinal axis, modeled through bars and shell elements. It was not purpose of this study the influence of meso and infrastructure of the bridge on its superstructure.

Precast concrete bridge deck panels have been used for decades to accelerate bridge construction. Cracking of the transverse connection between panels is a common problem that can damage deck overlays and cause connection leaking leading to corrosion of lower bridge elements. To better understand the behavior of bridge deck transverse female-to-female connections, shear and moment lab testing were performed at Utah State University for the Utah Department of Transportation. Two existing UDOT connections were tested, a welded stud connection and a post tensioned connection. A variation of the welded connection using rebar was also tested. In addition, two new curved bolt connections were tested as a new method of post tensioning a connection. The manner of connection cracking and associated cracking loads were recorded along with the ultimate connection capacities. The connections were also tested in a low cycle, high amplitude cyclical shear test. Lab testing showed that the welded stud connection had the lowest moment capacity. It also showed that the welded rebar connection had significantly higher strength than the welded stud connection with higher cracking and ultimate loads. Curved bolts were also shown to be a good way to post tension a connection with similar moment capacities as the post tensioned connection. Longer curved bolts were found to perform better than shorter curved bolts.

A full-depth precast concrete deck system presents several safety, timeline, and cost benefits to the process of constructing a bridge, however the relevant professional codes do not provide dependable design models due to the limited amount of research conducted on the subject. One area lacking design direction is the development of a shear connection between the full-depth precast deck and a precast concrete girder via a pocket-haunch-connector system. Push-off tests are performed to investigate the effects of various pre- and post-installed shear connectors, haunch height, surface roughness, grouping effects, and grout composition as compared to cast-in-place specimens. The experimental results are presented along with a method for normalizing the variations of results by connection yield strength. This method is used to evaluate each connector type and connection parameter investigated. Ensuring sufficient shear reinforcement within the beam near the shear connector anchorage is found to be a vital aspect of holistic design. A simplified design procedure is outlined, the design connection forcedisplacement behavior is shown, and an example problem is solved. Recommendations for additions and modifications to current code and practice are prescribed.