Construction Automation Using Pen-Based Computers, HR-368, 1996

The Iowa Department of Transportation is committed to improved management systems, which in turn has led to increased automation to record and manage construction data. A possible improvement to the current data management system can be found with pen-based computers. Pen-based computers coupled with user friendly software are now to the point where an individual's handwriting can be captured and converted to typed text to be used for data collection. It would appear pen-based computers are sufficiently advanced to be used by construction inspectors to record daily project data. The objective of this research was to determine: (1) if pen-based computers are durable enough to allow maintenance-free operation for field work during Iowa's construction season; and (2) if pen-based computers can be used effectively by inspectors with little computer experience. The pen-based computer's handwriting recognition was not fast or accurate enough to be successfully utilized. The IBM Thinkpad with the pen pointing device did prove useful for working in Windows' graphical environment. The pen was used for pointing, selecting and scrolling in the Windows applications because of its intuitive nature.

Micro-Computer Based Linear Scheduling Application for Highway Construction Project Control, HR-339A, 1995

This report describes a new approach to the problem of scheduling highway construction type projects. The technique can accurately model linear activities and identify the controlling activity path on a linear schedule. Current scheduling practices are unable to accomplish these two tasks with any accuracy for linear activities, leaving planners and manager suspicious of the information they provide. Basic linear scheduling is not a new technique, and many attempts have been made to apply it to various types of work in the past. However, the technique has never been widely used because of the lack of an analytical approach to activity relationships and development of an analytical approach to determining controlling activities. The Linear Scheduling Model (LSM) developed in this report, completes the linear scheduling technique by adding to linear scheduling all of the analytical capabilities, including computer applications, present in CPM scheduling today. The LSM has tremendous potential, and will likely have a significant impact on the way linear construction is scheduled in the future.

Electronic Construction Collaboration System – Phase III, December 2011

This phase of the electronic collaboration project involved two major efforts: 1) implementation of AEC Sync (formerly known as Attolist), a web-based project management system (WPMS), on the Broadway Viaduct Bridge Project and the Iowa Falls Arch Bridge Project and 2) development of a web-based project management system for bridge and highway construction projects with less than $10 million in contract value. During the previous phase of this project (fiscal year 2010), the research team helped with the implementation process for AEC Sync and collected feedback from the Broadway Viaduct project team members before the start of the project. During the 2011 fiscal year, the research team collected the post-project surveys from the Broadway Viaduct project members and compared them to the pre-project survey results. The results of the AEC Sync implementation on the Broadway project were positive. The project members were satisfied with the performance of the AEC Sync software and how it facilitated document management and its transparency. In addition, the research team distributed, collected, and analyzed the pre-project surveys for the Iowa Falls Arch Bridge Project. The implementation of AEC Sync for the Iowa Falls Arch Bridge Project appears to also be positive, based on the pre-project surveys. The fourth phase of this electronic collaboration project involves the identification and implementation of a WPMS solution for smaller bridge and highway projects. The workflow for the shop drawing approval process for sign truss projects was documented and used to identify possible WPMS solutions. After testing and evaluating several WPMS solutions, Microsoft SharePoint Foundation’s site pages were selected to be pilot-tested on sign truss projects. Due to the limitation on the SharePoint license that the Iowa Department of Transportation (DOT) has, a file transfer protocol (FTP) site will be developed alongside this site to allow contractors to upload shop drawings to the Iowa DOT. The SharePoint site pages are expected to be ready for implementation during the 2012 calendar year.

Guide to Cement-Based Integrated Pavement Solutions, August 2011

This guide provides a clear, concise, and cohesive presentation of cement-bound materials options for 10 specific engineering pavement applications: new concrete pavements, concrete overlays, previous concrete, precast pavements, roller-compacted concrete, cement-treated base, full-depth reclamation with cement, cement-modified soils, recycled concrete aggregates, and repair and restoration. Each application is presented as a method for meeting specific design and construction objectives that today’s pavement practitioners must accomplish. The benefits, considerations, brief description, and summary of materials, design, and construction requirements, as well as a list of sustainable attributes, are provided for every solution. This guide is intended to be short, simple, and easy to understand. It was designed so that the most up-to-date and relevant information is easily extractable. It is not intended to be used as a design guide for any of the applications identified herein. Recommendations for additional information that can provide such details are given at the end of each solution discussion. The intended audience is practitioners, including engineers and managers who face decisions regarding what materials to specify in the pavement systems they design or manage. The audience also includes city and county engineers, along with the A/E firms that often represent them, and state DOT engineers at all levels who are seeking alternatives in this era of changing markets.

Artificial-Intelligence-Based Optimization of the Management of Snow Removal Assets and Resources Final Report, October 2002

Geographic information systems (GIS) and artificial intelligence (AI) techniques were used to develop an intelligent snow removal asset management system (SRAMS). The system has been evaluated through a case study examining snow removal from the roads in Black Hawk County, Iowa, for which the Iowa Department of Transportation (Iowa DOT) is responsible. The SRAMS is comprised of an expert system that contains the logical rules and expertise of the Iowa DOT’s snow removal experts in Black Hawk County, and a geographic information system to access and manage road data. The system is implemented on a mid-range PC by integrating MapObjects 2.1 (a GIS package), Visual Rule Studio 2.2 (an AI shell), and Visual Basic 6.0 (a programming tool). The system could efficiently be used to generate prioritized snowplowing routes in visual format, to optimize the allocation of assets for plowing, and to track materials (e.g., salt and sand). A test of the system reveals an improvement in snowplowing time by 1.9 percent for moderate snowfall and 9.7 percent for snowstorm conditions over the current manual system.

Precast Concrete Elements for Accelerated Bridge Construction Final Report Volume 3. Laboratory Testing, Field Testing, and Evaluation of a Precast Concrete Bridge: Black Hawk County,v January 2009

The importance of rapid construction technologies has been recognized by the Federal Highway Administration (FHWA) and the Iowa DOT Office of Bridges and Structures. Black Hawk County (BHC) has developed a precast modified beam-in-slab bridge (PMBISB) system for use with accelerated construction. A typical PMBISB is comprised of five to six precast MBISB panels and is used on low volume roads, on short spans, and is installed and fabricated by county forces. Precast abutment caps and a precast abutment backwall were also developed by BHC for use with the PMBISB. The objective of the research was to gain knowledge of the global behavior of the bridge system in the field, to quantify the strength and behavior of the individual precast components, and to develop a more time efficient panel-to-panel field connection. Precast components tested in the laboratory include two precast abutment caps, three different types of deck panel connections, and a precast abutment backwall. The abutment caps and backwall were tested for behavior and strength. The three panel-to-panel connections were tested in the lab for strength and were evaluated based on cost and constructability. Two PMBISB were tested in the field to determine stresses, lateral distribution characteristics, and overall global behavior.

GIS - Based Decision and Outreach Tools for Aggregate Source Management, September 2008

This research project combined various datasets, existing and created for this project, into an Interactive Mapping Service (IMS) for use by Iowa DOT personnel, county planning and zoning departments and the public in order to make more informed decisions regarding aggregate sources and future access to them. Iowa DOT Technical Advisory Committee meetings were held, along with public forum presentations, in order to understand better the social, ecological and economic limitations to extracting aggregate. The information needed by potential users was conveyed and integrated into a single informational source, the Aggregate Planning IMS.

Wind Monitoring of the Saylorville and Red Rock Reservoir Bridges with Remote, Cellular-Based Notifications, May 2012

Following high winds on January 24, 2006, at least five people claimed to have seen or felt the superstructure of the Saylorville Reservoir Bridge in central Iowa moving both vertically and laterally. Since that time, the Iowa Department of Transportation (DOT) contracted with the Bridge Engineering Center at Iowa State University to design and install a monitoring system capable of providing notification of the occurrence of subsequent high winds. Although measures were put into place following the 2006 event at the Saylorville Reservoir Bridge, knowledge of the performance of this bridge during high wind events was incomplete. Therefore, the Saylorville Reservoir Bridge was outfitted with an information management system to investigate the structural performance of the structure and the potential for safety risks. In subsequent years, given the similarities between the Saylorville and Red Rock Reservoir bridges, a similar system was added to the Red Rock Reservoir Bridge southeast of Des Moines. The monitoring system developed and installed on these two bridges was designed to monitor the wind speed and direction at the bridge and, via a cellular modem, send a text message to Iowa DOT staff when wind speeds meet a predetermined threshold. The original intent was that, once the text message is received, the bridge entrances would be closed until wind speeds diminish to safe levels.

An Experimental Validation of a Statistical-Based Damage Detection Approach, January 2011

In this work, a previously-developed, statistical-based, damage-detection approach was validated for its ability to autonomously detect damage in bridges. The damage-detection approach uses statistical differences in the actual and predicted behavior of the bridge caused under a subset of ambient trucks. The predicted behavior is derived from a statistics-based model trained with field data from the undamaged bridge (not a finite element model). The differences between actual and predicted responses, called residuals, are then used to construct control charts, which compare undamaged and damaged structure data. Validation of the damage-detection approach was achieved by using sacrificial specimens that were mounted to the bridge and exposed to ambient traffic loads and which simulated actual damage-sensitive locations. Different damage types and levels were introduced to the sacrificial specimens to study the sensitivity and applicability. The damage-detection algorithm was able to identify damage, but it also had a high false-positive rate. An evaluation of the sub-components of the damage-detection methodology and methods was completed for the purpose of improving the approach. Several of the underlying assumptions within the algorithm were being violated, which was the source of the false-positives. Furthermore, the lack of an automatic evaluation process was thought to potentially be an impediment to widespread use. Recommendations for the improvement of the methodology were developed and preliminarily evaluated. These recommendations are believed to improve the efficacy of the damage-detection approach.

Development of a GPS-Based Sign Inventory Tool for Iowa’s Statewide Management System, May 2011

This report is on state-of-the-art research efforts specific to infrastructure inventory/data collection with sign inventory as a case study. The development of an agency-wide sign inventory is based on feature inventory and location information. Specific to location, a quick and simple location acquisition tool is critical to tying assets to an accurate location-referencing system. This research effort provides a contrast between legacy referencing systems (route and milepost) and global positioning system- (GPS-) based techniques (latitude and longitude) integrated into a geographic information system (GIS) database. A summary comparison of field accuracies using a variety of consumer grade devices is also provided. This research, and the data collection tools developed, are critical in supporting the Iowa Department of Transportation (DOT) Statewide Sign Management System development effort. For the last two years, a Task Force has embarked on a comprehensive effort to develop a sign management system to improve sign quality, as well as to manage all aspects of signage, from request, ordering, fabricating, installing, maintaining, and ultimately removing, and to provide the ability to budget for these key assets on a statewide basis. This effort supported the development of a sign inventory tool and is the beginning of the development of a sign management system to support the Iowa DOT efforts in the consistent, cost effective, and objective decision making process when it comes to signs and their maintenance.

Construction and Maintenance Practices to Minimize the Potential Liability of Counties for Roads in Rural Subdivisions, HR-221, 1981

In an earlier research project, HR-204, the magnitude and nature of highway related tort claims against counties in Iowa were investigated. However, virtually all of the claims identified in that research resulted from incidents that occurred in areas with predominantly agricultural land use. With recent increases in the rural non-farm population, many traditionally urban problems are also appearing in built-up areas under county jurisdiction. This trend is expected to continue so that counties must anticipate a change in the nature of the tort claims they will encounter. Problems that heretofore have been unique to cities may become commonplace in areas for which counties are responsible. The research reported here has been directed toward an investigation of those problems in rural subdivisions that lead to claims growing out of the provision of highway services by counties. Lacking a sufficient database among counties for the types of tort claims of interest in this research, a survey was sent to 259 cities in Iowa in order to identify highway related problems leading to those claims. The survey covered claims during a five year period from 1975 to 1980. Over one-third of the claims reported were based on alleged street defects. Another 34 percent of the claims contained allegations of damages due to backup of sanitary sewers or defects in sidewalks. By expanding the sample from the 164 cities that responded to the survey, it was estimated that a total of $49,000,000 in claims had been submitted to all 259 cities. Over 34% of this amount resulted from alleged defects in the use of traffic signs, signals, and markings. Another 42% arose from claims of defects in streets and sidewalks. Payments in settlement of claims were about 13.4% of the amount asked for those claims closed during the period covered by the survey. About $9,000,000 in claims was pending on June 30, 1980 according to the information furnished. Officials from 23 cities were interviewed to provide information on measures to overcome the problems leading to tort claims. On the basis of this information, actions have been proposed that can be undertaken by counties to reduce the potential for highway-related claims resulting from their responsibilities in rural subdivisions and unincorporated communities. Suggested actions include the eight recommendations contained in the final report for the previous research under HR-204. In addition, six recommendations resulted from this research, as follows: 1. Counties should adopt county subdivision ordinances. 2. A reasonable policy concerning sidewalks should be adopted. 3. Counties should establish and implement a system for setting road maintenance priorities. 4. Counties should establish and implement a procedure for controlling construction or maintenance activities within the highway right of way. 5. Counties should establish and implement a system to record complaints that are received relating to highway maintenance and to assure timely correction of defective conditions leading to such complaints. 6. Counties should establish and implement a procedure to ensure timely advice of highway defects for which notice is not otherwise received.

Minimum VMA in HMA Based on Gradation and Volumetric Properties, MLR-95-7, 1996

The use of voids in the mineral aggregate (VMA) criteria for proper mix design of hot mix asphalt (HMA) mixtures is a time honored and fairly successful tool. Recent developments in the field of asphalt mix design have encouraged the use of mixtures with a coarse aggregate structure to resist the affect of heavy traffic loads. By using the equations presented, which account for both aggregate gradation and the volumetric properties of the materials, the mix designer is able to judge the proper VMA requirement for each unique blend of materials. By applying the new equations, the most economical mix may be selected without great risk of reduced durability. Supporting data from field application is presented to illustrate the use of the equations.

Thin Asphalt Concrete Pavement on Crushed Rock Base - Cass County, Construction Report, HR-2075, 1997

The road paving cost continues to increase and the backlog of projects waiting for funding is growing. Finding a more cost-effective way to use the available money to pave roads will result in more miles of road being paved with the same amount of money. This project is in Cass County on G35 between US 71 and Norway-Center. It consists of a thin layer of asphalt over a base designed to achieve stability while having some permeability. This project was paved in 1996. An asphalt cement concrete pavement was chosen for the project based on cost, convenience, and historic portland cement concrete problems in Cass County. The new pavement gives quicker access time to farms and residences.

Performance Based Specifications, TR-403, 1998

The goal in highway construction and operation has shifted from method based specifications to specifications relating desired performance attributes to materials, mix designs, and construction methods. Shifting from method specifications to performance based specifications can work as an incentive or disincentive for the contractor to improve performance or extend pavement life. This literature search was directed at a review of existing portland cement concrete performance specification development, and the criteria that can effectively measure pavement performance. The criteria identified in the literature include concrete strength, slab thickness, air content, initial smoothness, water-cement ratio, unit weight, and slump. A description of each criterion, along with the advantages, disadvantages, and test methods for each are identified. Also included are the results from a survey that was sent out to various state, federal, and trade agencies. The responses indicated that 53% currently use or are developing a performance based specification program. Of the 47% of agencies that do not use a performance based specification program, over 34% indicated that they would consider a similar program. The most commonly measured characteristics include thickness, strength, smoothness, and air content. Lastly recommendations and conclusions are made regarding other factors that affect pavement performance and a proposed second phase of the research is suggested. The research team suggests that a regional expert task group be formed to identify performance levels and criteria. The results of that effort will guide the research team in the development of new or revised specifications.

Electronic Construction Collaboration System – Final Phase, SPR RB02-008, 2014

This phase of the research project involved two major efforts: (1) Complete the implementation of AEC-Sync (formerly known as Attolist) on the Iowa Falls Arch Bridge project and (2) develop a web-based project management system (WPMS) for projects under $10 million. For the first major effort, AEC-Sync was provided for the Iowa Department of Transportation (DOT) in a software as a service agreement, allowing the Iowa DOT to rapidly implement the solution with modest effort. During the 2010 fiscal year, the research team was able to help with the implementation process for the solution. The research team also collected feedback from the Broadway Viaduct project team members before the start of the project and implementation of the solution. For the 2011 fiscal year, the research team collected the post-project surveys from the Broadway Viaduct project members and compared them to the pre-project survey results. The result of the AEC-Sync implementation in the Broadway Viaduct project was a positive one. The project members were satisfied with the performance of AEC-Sync and how it facilitated document management and transparency. In addition, the research team distributed, collected, and analyzed the pre-project surveys for the Iowa Falls Arch Bridge project. During the 2012 fiscal year, the research team analyzed the post-project surveys for the Iowa Falls Arch Bridge project AEC-Sync implementation and found a positive outcome when compared to the pre-project surveys. The second major effort for this project involved the identification and implementation of a WPMS solution for smaller bridge and highway projects. During the 2011 fiscal year, Microsoft SharePoint was selected to be implemented on these smaller highway projects. In this year, workflows for the shop/working drawings for the smaller highway projects specified in Section 1105 of the Iowa DOT Specifications were developed. These workflows will serve as the guide for the development of the SharePoint pages. In order to implement the Microsoft SharePoint pages, the effort of an integrated team proved to be vital because it brought together the expertise required from researchers, programmers, and webpage developers to develop the SharePoint pages.