Preventive Maintenance Program for Bridges

Section 404 of the Clean Water Act (CWA) mandates that state agencies and other entities perform compensatory mitigation when their activities impair jurisdictional waters. In the Commonwealth of Kentucky, the Kentucky Transportation Cabinet (KYTC) is required to pay in-lieu fees or purchase stream mitigation credits when a roadside ditch is impaired or relocated as part of a road construction project. In-lieu fees and stream mitigation credits are costly, and ditches that have suffered degraded habitat and loss of hydrogeomorphic functionality are treated as total losses when they are impacted by construction and maintenance activities. This raises the question of whether the United States Corps of Engineers (USACE) would be receptive to alternative mitigation and monitoring practices that impose a less stringent financial burden on the Kentucky Transportation Cabinet, but which still comply with CWA regulations. This report discusses methodologies used to evaluate the quality of instream and riparian habitat, Section 404 of the CWA and its implications for mitigation of lost or damaged jurisdictional ditches, and the strategies that have been used by other states to fulfill their Section 404 mitigation requirements. The authors highlight mitigation practices that depart from the norm and which place a less onerous financial burden on state transportation agencies. KYTC officials presented this report’s key findings to the USACE Louisville District Office in January 2015 in an effort to receive approval to experiment with novel restoration techniques. The USACE granted KYTC license to implement these techniques on a project-by-project basis. Before implementation on each project, the Cabinet must receive formal approval from USACE officials. Although this was not the blanket mandate that KYTC hoped for, it indicated the Louisville District is willing to study the effectiveness of alternative mitigation strategies. Despite the Cabinet’s request, USACE officials did not approve a plan to reduce post-restoration monitoring requirements. Kentucky Transportation Center (KTC) researchers suggested that KYTC perform exhaustive monitoring of the performance of completed projects that used alternative mitigation techniques. Having information on the short-, medium-, and long-term performance of these sites could – if the results are promising – pave the way to the wider adoption of alternative mitigation practices and could eventually reduce the level of post-restoration monitoring required by the USACE.

PurposeThis study focuses on the application of reliability-centered maintenance (RCM) to a textile industry steam boiler. The study aims to demonstrate the development and application of RCM to a steam boiler used in the textile industry.Design/methodology/approachRCM is a structured process that develops maintenance activities needed on physical resources in their operational environment to realize their inherent reliability by logically incorporating an appropriate mixture of reactive, preventive, condition-based and proactive maintenance methods. A detailed analysis of the RCM approach is presented to develop preventive maintenance (PM) program and improve the reliability and availability of the steam boiler system.FindingsThe research reveals that the identification of PM tasks is a good indicator of the PM program's efficiency and can serve as an important maintenance-related downtime source. It is also discovered that the majority of maintenance programs that claim to be proactive are, in fact, reactive. This article also shows how RCM may be successfully implemented to any system, resulting in increased system reliability.Research limitations/implicationsThe paper focuses on a pilot study of the development and implementation of the RCM technique to a textile industry steam boiler. It is suggested that the developed RCM model can be applied to the entire plant.Originality/valueThe paper presents a comprehensive RCM model framework as well as an RCM decision framework, providing maintenance managers and engineers with a step-by-step approach to RCM implementation. The proposed framework is significant in that it may be utilized for both qualitative and quantitative analysis at the same time.

This paper investigates integrated two-stage assembly flow shop problem with preventive maintenance (PM) activities under the multi-objective optimisation approaches. Reliability models are employed to carry out the maintenance activities. This paper attempts to find the appropriate sequence of jobs on machines in order to minimise the makespan and determining when to perform the PM activities in order to minimise the system unavailability. As this problem is proven to be NP-hard two multi-objective optimisation methods that are named non-dominated sorting genetic algorithm II (NSGA-II) and non-dominated ranking genetic algorithm (NRGA) are employed to find the Pareto-optimal front. The parameters of proposed algorithms are calibrated by artificial neural network (ANN) and the performances of the algorithms on the problem of various sizes are analysed based on four metrics. The computational results reveal NRGA is statistically better than NSGA-II.

This study created an information base to improve decisions about the replacement or rehabilitation of historic truss bridges. During the first phase of the research, information on the history and design of the 109 bridges in the study was assembled. With the assistance of historic preservation professionals, 75 of those bridges were selected for further study for their potential for rehabilitation. During the second phase, the KTC research team, engineers from the KYTC bridge division, and 12 highway district engineers, who are responsible for the day-to-day care and maintenance of the bridges, evaluated the condition and functional context of the 75 bridges. The goal was to identify those that are good candidates for preservation through rehabilitation. The district engineers were of the opinion that only 14 of the 75 bridges needed to be replaced. However, there was an additional subset of 13 bridges that, in their opinion, present some significant obstacles to preservation related to functional inadequacy or some other problem with the bridge. The bridge engineers estimated considerably higher levels of effort to preserve these 13 bridges (an average of 7.42 on a 10 point scale) than for the 48 remaining bridges (an average of 3.82 on the 10 point scale).

2 - Preventive Maintenance—Definition and Structure

PurposeThis paper aims to propose an approach for the optimization of imperfect preventive maintenance and corrective actions performed on a single machine. After maintenance, the machine returns to an age between “as good as new” and “as bad as old”.Design/methodology/approachThe approach is based on fuzzy logic and simulation‐based optimization. Fuzzy logic is preferred over crisp logic because it is relatively easy to implement in this situation considering that the human factor is hardly interpreted by analytical methods because of its unpredictable nature. Simulation‐based optimization is used to have a more reactive and accurate tool for practitioners.FindingsTaking into account the impact of the imperfections due to human factors, the period for preventive maintenance, which minimizes the expected cost rate per unit of time or maximizes the availability of the system, is evaluated by the simulation‐based optimization.Research limitations/implicationsDifferent and more realistic maintenance levels must be considered and the traceability of a specific system could be used to determine the most appropriate failure law. For this study, cost reduction was considered as the priority, but the model can be adjusted according to the user's preferences.Practical implicationsThis paper considers a single repairable machine as a system that undergoes periodic preventive and corrective maintenance actions. Considering maintenance imperfections, rule‐based fuzzy logic can be integrated into the maintenance program to determine the times for the periodic preventive maintenance actions.Originality/valueConsidering human factors in maintenance programs is indispensable to assure more accurate and realistic results. However, due to the difficulty engendered by their modeling, most theoretical maintenance models do not consider these factors. Therefore, the proposed fuzzy model in the paper can be an important tool to include them.

The Kentucky Transportation Center, the Asphalt Institute, and the Kentucky Transportation Cabinet worked together in order to identify factors that affect asphalt pavement density, and to then evaluate their effect on long term pavement performance. By determining which variables are most influential to pavement performance (i.e. roller pattern, temperature when rolled, etc.), and then monitoring the attention given to those variables, Kentucky would be able to increase the service life of asphalt roadways by at least 25%, therefore saving as much as $30 million annually on a resurfacing budget of $129.2 million (2007), while still maintaining the current roadway level of service. Ensuring that the pavement roller is able to roll the surface at the appropriate temperature can result in increases in density of up to 4%. An asphalt mix having 11% voids failed at approximately 400,000 cycles @ 350 microstrains, compared to that same mix at 7% air voids failing at 600,000 cycles @ 350 microstrains, resulting in a lab fatigue life increase of 50%. Two primary results were found from this study. First, by ensuring the compaction roller reaches the pavement before the temperature is allowed to drop substantially, up to a 4% increase in density can be achieved. Second, by increasing density 4%, lab fatigue life can be increased by as much as 50%. From these results, by practicing proper construction techniques one could conservatively expect to see increases in the service life of an asphalt surface of up to 25% in the field.

Q: Due to constraints in our biomed budget, I was wondering: Is there anyway to reduce the rotations for sterilizers in our preventive maintenance (PM) program?A: Sure. In fact, several years ago, we reduced the rotation and the items we change on sterilizers. Our facility has 11 operating rooms (OR) and two labor-and-delivery rooms. Our sterilizers get fairly heavy use between 6 a.m. and 11 p.m. But we're definitely not as busy as facilities that run 24 hours a day, 365 days a year. So we reduced the PM schedule for some of them to a semiannual basis. This process has worked very well. We have not had any more failures than we had when we did them quarterly. We saved ourselves time and the materials we would have had in replacing those quarterly parts. Certain sterilizers, like the washer-sterilizers, still undergo quarterly PM due to their fairly heavy use and the fact that we only have two in the OR. If one goes down, the impact to our customer is significant.I am making my suggestions based on the assumption that your facility has a good preventive maintenance program and some sort of a program that enables you to track equipment. By tracking equipment repairs, you can monitor the results if you reduce your facility's PM schedule. Our facility continuously monitors work requests through a program in our database. This program allows use to “write” almost any report one can imagine. For example, one of our performance indicators is repeat work requests. We have a report that compiles all such requests during a given period—three months, in our case. Each technician is given the piece of the report related to the equipment that he or she is responsible for. The technician then checks the work requests for that equipment, looking for anything that can be incorporated into a regular PM schedule and prevent a failure. This allows your facility to “hold all the cards,” so to speak. If someone at your facility periodically monitors your success, you will be able to adjust your PM program accordingly.As for what parts can be reduced, that depends on several factors such as use, steam quality, water quality, and maintenance program effectiveness. Our water here tends to be higher in calcium than most parts can tolerate. So we keep water traps and water solenoids on a semiannual schedule. That said, our steam quality is fairly good, and we push our steam parts as long as possible. When we looked at ways to reduce cost, we looked along the line of steam—not water.Another key factor is staff care with equipment. For example, we once had someone in the instrument room who would slam the doors of the sterilizers so hard that the machines shook. We talked to him on several occasions, but he slammed the door right up until his last day at our facility. If that was not bad enough, after slamming it one time, this now-former employee cranked hard on the handle and then brought it to me to report, “It's broke.” Ha, ha! While he worked at our facility, we stepped up the PM frequency on the doors. We would check the handles for tightness, the arms that wind out to make sure they were not missing their holders, the door seal which would snap if brittle and the door was slammed, and the door cover to make sure it had not been bent.But let me end by returning to the big picture. You can and should alter your PM schedule to maximize your resources. Working with a good database, a good PM program can save you time and money. Remember: Garbage in, garbage out.

An integrated maintenance and power generation forecast by ANN approach based on availability maximization of a wind farm

This study investigated the breakdown trend in an automated production with an aim to recommend the application of reliability-centered maintenance (RCM) for improved productivity via a new preventive maintenance (PM) program. An individual section-forming machine (ISM)—a glass blowing machine for making glass bottles—was used as the case study for an automated production system. The machine parts and the working mechanisms were analysed with a special focus on methods of processes and procedures. This will enable the ISM maintenance department to run more effectively and achieve its essential goal of ensuring effective machine operation and reduction in machine downtime. In this work, information is provided on the steps and procedures to identify critical components of the ISM using failure modes and effect analysis (FMEA) as a tool to come up with an optimal and efficient maintenance program using the reliability data of the equipment’s functional components. A relationship between the failure rate of the machine components and the maintenance costs was established such that using the recommended PM program demonstrates evidence of an improvement in the machine’s availability, safety, and cost-effectiveness and will result in an increase in the company’s profit margin.

This report addresses issues related to transferring the responsibility for quality control from the Kentucky Transportation Cabinet (KyTC) to construction contractors. Surveys of the KyTC, other state departments of transportation, and Kentucky highway contractors were done to identify the advantages, concerns, and modifications of the Contractor Performed Quality Control (CPQC) program. An advisory committee of experienced KyTC engineers, Federal Highway Administration representatives, and contractor representatives met periodically to identify approaches for handling key issues of the program. Several key topics related to CPQC are presented in this report, with emphasis on quality control/quality assurance (QC/QA) administration, QC/QA procedures, quality acceptance and verification testing, and CPQC training. Specific issues related to CPQC pay items in Kentucky are also discussed. Several recommendations have been proposed to enhance the program. If properly implemented, CPQC can improve a contractor's work performance and help relieve the State's burden for inspection. Additional monitoring of the program is necessary to make further improvements and to include other pay items.

In this chapter maintenance concept is defined and maintenance types are classified with regard to implementing maintenance policies toward preventive maintenance. Especially achieving planned maintenance policies toward preventive (planned) maintenance and condition based maintenance policies toward predictive maintenance is taken into consideration primarily. Maintenance concept is defined and maintenance types are classified. Due care is given for ‘Preventive Maintenance’ in this chapter. In general ‘Maintenance’ term could be defined as; The integration of all possible technical and administrative actions, including planning, supervising, monitoring and controlling toward retaining an item, a system, a machine to restore their original functional state in which they can perform the intended functions. In addition maintenance, include protective and corrective actions to keep the plant operational system in intended conditions or to maintain the acceptable manufacturing conditions. Optimum maintenance policies aims to sustain system reliability and robustness within minimum cost. In line with the progress of industry, increase in the system, material and manpower costs, increasing demand for robustness and the complex structure of the machines increases also the importance of maintenance policies. Maintenance types could be divided into two main parts namely; 1. Preventive Maintenance, 2. Corrective Maintenance. Preventive Maintenance is also classified into following sub groups; 1.a- Planned Maintenance, 1.b- Predictive Maintenance, 1.c- Advanced Maintenance Implementations; 1.c.1 Reliability Centered Maintenance 1.c.2 Risk Based Maintenance. All of these maintenance types elaborated with relevant figures in the chapter. In this chapter Comparison of Planned and Unplanned (corrective) Maintenance (With regard to transaction and output) is defined with a table. Additionally, Comparison of Planned and Unplanned (corrective) Maintenance (With regard to infra structure) is also tabulated. ‘Benefits of Preventive & Predictive Maintenance’ and ‘Predictive Maintenance Methods’ are defined with relevant descriptive figures in the chapter. For Corrective Maintenance, basic definitions and corrective maintenance steps, types of corrective Maintenance, improvement strategies in corrective maintenance effectiveness are also given. In the final part of ‘Results and conclusions’ expected and verified benefits of implementing maintenance policies for planned and predictive maintenance are explained. Comparisons in some maintenance policies is given.

Three recently completed road construction projects were investigated to determine Kentucky Transportation Cabinet (KYTC) effectiveness in implementing project commitments (including environmental commitments). Documentation was obtained from KYTC districts in which the projects were constructed and KYTC officials involved with the projects from planning through construction were interviewed. The projects were inspected to audit completion of project commitments. Key stakeholders (officials of local governments, resource agencies, metropolitan planning organizations, interest groups, and adjacent landowners) were interviewed about the projects. They were asked to grade KYTC for implementation of project commitments using a standard report card format. The findings for these investigations are presented. The auditing procedure employed in this study can be used to rate future KYTC projects, identify problems, and suggest solutions.

This paper studies the two-stage assembly flow shop problem (TAFSP) considering aging effects of the machines and preventive maintenance activities. At the first stage, m-1 parallel machines process parts of each jobs, and at the second stage, related parts of the jobs are assembled by one assembly machine. As the machines work on the jobs, their tools get aged. Aging effects on the machines causes that they will not be able to complete the jobs in the same time could as they were new or when they are operating jobs immediately after their preventive maintenance activity. Processing times of the job are related to the positions, in which it is located after the last preventive maintenance. The job that is operated in a position immediately after the preventive maintenance activity on a machine has its standard processing time. However, the processing time of the jobs operated in the further positions increase based on the number of the positions. The machines return to the initial condition after each preventive maintenance activity. The objective is to schedule the jobs on the machines and determine when the preventive maintenance activities get done on them in order to minimize the total weighted tardiness and maintenance costs. An integer mathematical model is presented for the problem and its validation is shown by solving an example in small scale. Since two-stage assembly flow shop problem is NP-hard, in order to solve the problem in medium and large scale two meta-heuristic algorithms, hybrid genetic algorithm (HGA) and hybrid particle swarm optimization (HPSO) are proposed. These algorithms are the hybrid version of genetic algorithm and particle swarm optimization representatively with simulated annealing. The algorithms are tuned by using Taguchi method, and are used to solve many numerical examples. Finally, the statistical analysis illustrates that the performance of HPSO is better than HGA.

The Kentucky Transportation Center (KTC) at the University of Kentucky has performed a series of research studies for the Kentucky Transportation Cabinet (KYTC) to monitor various experimental bridge painting projects and conduct investigative work focusing on new paint systems. The research study presented in this report addressed experimental projects in fiscal years 2001 and 2002. KTC and KYTC Project Design Team joint efforts in 2000 into early 2001 centered on the preparation of experimental bridge maintenance painting special notes, preliminary field testing/development of new experimental paint systems and testing of proprietary and KYTC standard specification coatings. The laboratory tests identified candidate coating systems that were subsequently used in the KYTC experimental bridge maintenance painting projects conducted under this study. Developmental work focused on total removal and some overcoating systems. The objectives of experimental project monitoring were to: assess the condition of existing paint systems on bridges prior to maintenance painting, monitor the project throughout completion, note problems, describe problem resolution, appraise the condition of the final product, and report observations and/or conclusions about the project. This report begins with a summary of the coatings testing work undertaken by KTC researchers and the KYTC Project Design Team. The experimental bridge maintenance painting monitoring work is presented for each bridge in the appendices. The overall results/findings of this research study are contained in the Conclusions section of this report.