State Departments of Transportation (DOT's) have established Bridge Management Systems (BMS) with procedures to aid in estimating service lives of bridge components and elements. Service life estimates, together with cost information, are used to develop life-cycle costs of bridges. These estimates are necessary to prioritize and optimize bridge improvement programs within budgetary constraints. Several factors, including age, traffic, and environment have been identified in current BMS literature as being directly responsible for the deterioration of bridge components or elements. However, no formal methodology exists to determine the effects of the environment. Estimating bridge elements service lives, without considering the effect of environmental factors, could potentially lead to biased estimates. A methodology is proposed using statistical analysis to determine the effects of environmental regions on service life estimates of steel girder bridge component (concrete deck) and element/protective system (girder paint) using bridge inspection field data collected by bridge inspectors. Further, existing deterioration models are incapable of using the non-numeric element level inspection data, which most state DOT's have been collecting for nearly thirty years per Federal Highway Administration guidelines. The data format used were the numerical condition appraisal scale (9 through 0) for concrete deck component, and the letter condition appraisal (G-F-P-C) for steel girder paint element. The methodology proposed an environmental classification system for use in BMS programs. In addition, least squares mean and corresponding standard errors and also means and corresponding standard deviations of service lives at the component and element/protective system levels were estimated. The steel girder paint estimated service lives can be used in scheduling maintenance, repair and rehabilitation operations, and also in life-cycle costs analysis at the project and network levels. Because of limitations in the concrete deck data sets, the estimated concrete deck service lives are not true estimates of their service lives but do reflect the influence of environmental exposure characteristics on their performance. / Ph. D.

With the recent developments of several bridge managements systems and their wide-spread use, bridge engineers are realizing the importance of systematic and well planned investments and appropriate management. However the results are far from satisfactory. Bridge management systems need more effective policy analysis tools that can take advantage of the vast amounts of available information to be more efficient. The objective of this research is to develop a policy analysis tool, which is generic in nature and can be applied to any bridge management system provided all the appropriate data is available. In particular, this policy analysis tool is geared to suit policy making, planning and budgeting for the interstate bridges in the state of Virginia. The policy analysis tool developed in this research is a discrete event simulation model capable of extracting information from text files in the Pontis Data Interchange format and simulate user defined element level policies. The model testing was performed using the interstate bridges of the Salem district in Virginia. All the relevant information was extracted from their PONTIS databases. Several scenarios with varying network policies were simulated. The results indicate the validity and the accuracy of the model. The policy analysis tool is a useful addition to the existing policy analysis tools and is capable of handling probabilistic distributions of data instead of single value averages. This will enable the tool to capture more information thereby making the simulation model more realistic. The general framework that was developed here can be applied to any infrastructure problem, and eventually it should be possible to achieve a discrete event simulation based integrated infrastructure management system. / Master of Science

No description available.

The trend in many countries is to outsource maintenance with competitive tendering. The design of the tender is then a crucial issue. A new type of tendering contract, called "Integrated Bridge Maintenance", was introduced in one experimental area in Sweden. In this case the preventive bridge maintenance is separated from the standard road maintenance contract. The ideas behind these changes are that the new approach can increase efficiency through a combination of in­creased specialization, economies of scale and through giving the private contractor a greater degree of freedom concerning exactly what to do and exactly when to do it. A pilot project has been running since 2004 for all bridges in Uppsala County with about 400 bridges and since 2007 for all bridges in Örebro County with about 700 bridges.   The experiences and lessons from this pilot project are presented in this thesis together with guidelines on how to procure Integrated Bridge Maintenance in the future. An important feature of the contract was that it contained a combination of specific measures that the contractor should carry out and properties of the bridges that the contractor was responsible to maintain. This created a balance between predictability and flexibility for the contractor. The contractor could make long term planning for the work. The client was satisfied because of increased com­petence and a low price. The latter can partly be explained by the possibility for the specialised bridge crew to receive additional work from other clients. As information about old bridges always is incomplete a partnering structure needs to be built into the contract. Experi­ence has also shown that a conscious policy to maintain long run competition is important. The general conclusion is that the project was seen as successful and as creating more "value for money".   To manage a bridge stock optimally from a life cycle perspective is a very complex task, since the condi­tions for the individual bridge can vary greatly from place to place which the answers from the research questions indicate. Besides following-up and evaluating the Integrated Bridge Maintenance projects a number of research questions have been studied.   Is Integrated Bridge Maintenance a successful method to increase the effectiveness and to increase the standard in bridge maintenance alternatively increasing the service life for the bridge stock at an optimal cost, i.e., will IBM lead to lower LCC? It is difficult to answer this question with exact numbers after so short time, but so far the opinion is that the effectiveness has increased. How can a bridge stock develop over a long time e.g. 15 years? Based on historical data one can calculate, for instance, new construction rate, demolition rate and average age for the bridge stock. This information could together with different future scenarios be a basis for different bridge management strategies for the actual bridge stock. What is the real service life for a bridge? Survival analysis for the different types of bridges in the actual bridge stock will give a good estimate of the different expected service life. Why and at which age are bridges de­molished? Two main reasons were found in this study: deterioration process of the bridge had gone too far and/or load bearing capacity was too low, and road were rerouted. What is the real service life for a bridge edge beam, one of the most often repaired element of Swedish bridges? Survival analysis of edge beams located on different types of roads will give a good estimate of the different expected service life.   How should a long-term contract for bridge maintenance and specially Integrated Bridge Maintenance be procured? The bridge manager should have a good understanding of the answers on the research ques­tions above when the tender documents are to be prepared for the actual bridge stock. Thereafter the area that the contract should cover could be chosen, a good balance between properties and measures, defining the working cycle for properties, a flexible partnering structure in the contract and a suitable length of the contract (x years) inclusive an option (+ y years) and finally good incentives in the contract.   To sum up, the main purpose with the doctoral project has been reached. A model for procurement of bridge maintenance has been developed; see the projects in Uppsala and Örebro. The contractor has deve­loped more effective methods for bridge maintenance. The doctoral project has been a step closer to the end goal of reducing the society’s costs for bridge maintenance in the future. The bridges should be func­tional to the lowest possible cost during its expected service life (LCC). The doctoral project has also con­tributed with new knowledge in the area of bridge maintenance, the actual development of a bridge stock over time, real service life for road bridges in Sweden and survival analysis. / QC 20100826

A Damage Assessment Model, Construction Process Model and Parametric Quantity Model were developed with the purpose of capturing the engineering knowledge involved in the estimating process of bridge repair construction projects. The Damage Assessment Model was used to create a sample database in which detailed inspection data was stored in a format compatible with the existing Pontis?tabase. Detailed inspection data, which provided quantitative values for the different damage types observed in bridges, could be retrieved from the sample database so that data could be used as either input parameters in the knowledge rules that triggered the selection of construction tasks in the Construction Process Model, or data could be used as variables in the equations used to estimate quantities in the Parametric Quantity Model. The Construction Process Model was used to incorporate the logic behind the construction process for different repair methods. The Construction Process Model was composed of seven repair matrices that defined specific repair methods for each Pontis?idge element. Construction tasks were grouped in construction modules that were modeled as flowcharts. Each construction module flowchart was composed of construction tasks arranged in sequential order and decision points that triggered the selection of construction tasks based on input parameters and knowledge rules. Input parameters were provided by the user, retrieved from the model or pre-defined in the model by expert knowledge. The construction modules developed involved construction tasks related to the repair of concrete bridge piles that were damaged due to reinforcement corrosion and related concrete deterioration. Data describing the construction tasks that were considered in the construction module flowcharts were modeled using the entity-relationship model and were stored in the sample database described previously. The Parametric Quantity Model combined data generated by the Damage Assessment Model and the Construction Process Model with additional expert knowledge and parameters into equations that were used to estimate quantities. The author investigated the use of neural networks as a tool to predict actual damage in bridge piles, conducted a preliminary survey to define labor productivity factors and collected data to define the duration of construction activities related to bridge repair.

In recent years, infrastructure renewal has been a focus of attention in North America and around the world. Municipal and federal authorities are increasingly recognizing the need for life cycle cost analysis of infrastructure projects in order to facilitate proper prioritization and budgeting of maintenance operations. Several reports have highlighted the need to increase budgets with the goal of overcoming the backlog in maintaining infrastructure facilities. This situation is apparent in the case of bridge networks, which are considered vital links in the road network infrastructure. Because of harsh environments and increasing traffic volumes, bridges are deteriorating rapidly, rendering the task of managing this important asset a complex endeavour. While several bridge management systems (BMS) have been developed at the commercial and research level, they still have serious drawbacks, particularly in integrating bridge-level and network-level decisions, and handling extremely large optimization problems. To overcome these problems, this study presents an innovative bridge management framework that considers network-level and bridge-level decisions. The initial formulation of the proposed framework was limited to bridge deck management. The model has unique aspects: a deterioration model that uses optimized Markov chain matrices, a life cycle cost analysis that considers different repair strategies along the planning horizon, and a system that considers constraints, such as budget limits and desirable improvement in network condition. To optimize repair decisions for large networks that mathematical programming optimization are incapable of handling, four state-of-the art evolutionary algorithms are used: Genetic algorithms, shuffled frog leaping, particle swarm, and ant colony. These algorithms have been used to experiment on different problem sizes and formulations in order to determine the best optimization setup for further developments. Based on the experiments using the framework for the bridge deck, an expanded framework is presented that considers multiple bridge elements (ME-BMS) in a much larger formulation that can include thousands of bridges. Experiments were carried out in order to examine the framework???s performance on different numbers of bridges so that system parameters could be set to minimize the degradation in the system performance with the increase in numbers of bridges. The practicality of the ME-BMS was enhanced by the incorporation of two additional models: a user cost model that estimates the benefits gained in terms of the user cost after the repair decisions are implemented, and a work zone user cost model that minimizes user cost in work zones by deciding the optimal work zone strategy (nighttime shifts, weekend shifts, and continuous closure), also, decides on the best traffic control plan that suits the bridge configuration. To verify the ability of the developed ME-BMS to optimize repair decisions on both the network and project levels, a case study obtained from a transportation municipality was employed. Comparisons between the decisions provided by the ME-BMS and the municipality policy for making decisions indicated that the ME-BMS has great potential for optimizing repair decisions for bridge networks and for structuring the planning of the maintenance of transportation systems, thus leading to cost savings and more efficient sustainability of the transportation infrastructure.

Bridges are vital links in many transport networks and represent a big capital investment for both governments and taxpayers. They have to be managed in a way that ensures society's needs are optimally met. In many countries, bridges are mainly managed using bridge management systems (BMSs). Although many BMSs contain some forms of life-cycle costing (LCC), the use of LCC in bridge engineering is scarce. LCC in many BMSs has mainly been applied within the bridge operation phase, even though it has several useful applications within the bridge entire life, from cradle to grave. This licentiate thesis discusses the need of a BMS with integrated comprehensive LCC tools that can assist decision-makers at all levels and within all phases in selecting the most cost-effective alternative from an array of applicable alternatives. The thesis introduces the Swedish Bridge and Tunnel Management System (BaTMan). Acomprehensive integrated LCC implementation scheme is illustrated, taking into account the bridge investment and management process in Sweden. The basic LCC analytical tools as well as other helpful LCC techniques are addressed. Detailed case studies for real bridges at different investment phases are presented to demonstrate the recent improvement of BaTMan practically in the LCC integration. Cost records for 2,508 bridges extracted from BaTMan inventory data are used as input data in the presented case studies. Considering the same records, the average real and anticipated initial costs of different bridge types in Sweden will schematically be presented. The thesis introduces a bridge LCC program developed over this research named "BaTMan-LCC". The reason for which this program was developed is to combine all possible LCC applications for bridges in one tool and facilitate its implementation. The sensitivity analysis as well as the LCC saving potential highlighted in the presented case studies emphasizes the feasibility and the possibility of developing BaTMan to accommodate the applications of BaTMan-LCC. / QC 20120301 / ETSI

In recent years, infrastructure renewal has been a focus of attention in North America and around the world. Municipal and federal authorities are increasingly recognizing the need for life cycle cost analysis of infrastructure projects in order to facilitate proper prioritization and budgeting of maintenance operations. Several reports have highlighted the need to increase budgets with the goal of overcoming the backlog in maintaining infrastructure facilities. This situation is apparent in the case of bridge networks, which are considered vital links in the road network infrastructure. Because of harsh environments and increasing traffic volumes, bridges are deteriorating rapidly, rendering the task of managing this important asset a complex endeavour. While several bridge management systems (BMS) have been developed at the commercial and research level, they still have serious drawbacks, particularly in integrating bridge-level and network-level decisions, and handling extremely large optimization problems. To overcome these problems, this study presents an innovative bridge management framework that considers network-level and bridge-level decisions. The initial formulation of the proposed framework was limited to bridge deck management. The model has unique aspects: a deterioration model that uses optimized Markov chain matrices, a life cycle cost analysis that considers different repair strategies along the planning horizon, and a system that considers constraints, such as budget limits and desirable improvement in network condition. To optimize repair decisions for large networks that mathematical programming optimization are incapable of handling, four state-of-the art evolutionary algorithms are used: Genetic algorithms, shuffled frog leaping, particle swarm, and ant colony. These algorithms have been used to experiment on different problem sizes and formulations in order to determine the best optimization setup for further developments. Based on the experiments using the framework for the bridge deck, an expanded framework is presented that considers multiple bridge elements (ME-BMS) in a much larger formulation that can include thousands of bridges. Experiments were carried out in order to examine the framework’s performance on different numbers of bridges so that system parameters could be set to minimize the degradation in the system performance with the increase in numbers of bridges. The practicality of the ME-BMS was enhanced by the incorporation of two additional models: a user cost model that estimates the benefits gained in terms of the user cost after the repair decisions are implemented, and a work zone user cost model that minimizes user cost in work zones by deciding the optimal work zone strategy (nighttime shifts, weekend shifts, and continuous closure), also, decides on the best traffic control plan that suits the bridge configuration. To verify the ability of the developed ME-BMS to optimize repair decisions on both the network and project levels, a case study obtained from a transportation municipality was employed. Comparisons between the decisions provided by the ME-BMS and the municipality policy for making decisions indicated that the ME-BMS has great potential for optimizing repair decisions for bridge networks and for structuring the planning of the maintenance of transportation systems, thus leading to cost savings and more efficient sustainability of the transportation infrastructure.

The purpose of this research was to develop a new index for concrete bridge deck management in Utah. Data were collected in the summer of 2005 from 15 concrete bridge decks in the vicinity of Salt Lake City. The decks ranged from 2 to 21 years in age and were all constructed using epoxy-coated rebar. Visual inspection, sounding, Schmidt hammer testing, half-cell potential testing, and chloride concentration testing were performed on six 6-ft by 6-ft test areas randomly distributed within the single lane closed to traffic on each deck, and testing protocols followed American Society for Testing and Materials standards to the extent possible. Collected data were analyzed using statistics, and age, cover, and half-cell potential were ultimately selected for inclusion in a new Utah Bridge Deck Index (UBDI); these variables effectively reflect chloride-induced corrosion mechanisms active on Utah bridge decks, are highly correlated to delamination distresses, and are relatively easy to measure compared to chloride concentration. At the request of Utah Department of Transportation (UDOT) personnel, the UBDI equation was structured around a deduct system using a 100-point scale similar to the sufficiency rating system, in which a perfect bridge deck receives a score of 100. Coefficients were selected based largely on the judgment of the researchers and the UDOT personnel involved in the research, and threshold values for maintenance, rehabilitation, and replacement (MR&R) options were specified to be the same as those associated with the standard sufficiency ratings. The UBDI and corresponding MR&R recommendation were then provided for each of the bridge decks tested in this research; nine of the decks are recommended for preventive treatment, and six are recommended for rehabilitation. In addition, the possibility of treatment applications was considered, leading to required adjustments in the UBDI calculation; the treatment options that were considered include an epoxy seal, an HPC overlay, and an asphalt membrane overlay. Four case scenarios were developed to demonstrate the response of the revised UBDI equation to these treatments. Finally, as aids for UDOT personnel implementing this research, charts were created to facilitate rapid determination of the required number of half-cell potential and concrete cover measurements for different levels of reliability and tolerance. The UBDI developed in this research is recommended for implementation by UDOT personnel as a tool for optimizing the timing of MR&R treatments on concrete bridge decks similar to those evaluated in this project. In measuring cover and half-cell potential values, UDOT personnel should utilize the sampling guidelines presented in this report to ensure adequate characterization of each deck. Furthermore, to facilitate the inclusion of treatment effects in the UBDI, UDOT personnel should establish a policy of recording the types and dates of all MR&R treatments applied to bridge decks. As performance data are collected for specific treatments over time, the treatment lives proposed in this research for epoxy seals, HPC overlays, and asphalt membrane overlays should be revised as needed, and information for other treatments may be added. In addition, to maximize the predictive capabilities of the UBDI, more accurate relationships between half-cell potential values and deck age should be developed for estimating future deck condition.