Restoration of Fricitonal Characteristics on Older Portland Cement Concrete Pavement:Final Report for Iowa Highway Research Board Project HR-224, June 1986

Safety i s a very important aspect o f the highway program. The Iowa DOT initiated an inventory o f the friction values of all paved primary roadways i n 1969. This inventory, with an ASTM E-274 test unit, has continued to the present time. The t e s t i n g frequency varies based upon traffic volume and the previous friction value. Historically , the state o f Iowa constructed a substantial amount o f pcc pavement during the 1928-30 period t o "get Iowa out o f the mud". Some of that pavement has never been resurfaced and has been subjected to more than 50 years o f wear. The textured surface has been worn away and has subsequently polished. Even though some pavements from 15 t o 50 years old continue t o function structurally , because of the loss of friction , they do not provide the desired level o f safety to the driver. As a temporary measure, "Sl ippery -When -Wet " signs have been posted on many older pcc roads due to friction numbers below t h e desirable level. These signs warn the motorist of the current conditions. An economical method of restoring the high quality frictional properties i s needed.

Iowa Research with Chem-Crete Bitumen: Final Report Iowa Highway Research Board Project HR-226, June 1986

With the spiraling cost of construction, coupled with inflation, engineers must develop and research new techniques to better utilize the public's dollar. One area i n which these new technologies must be researched is in the field of highway construction; more specifically, asphalt products. There are areas within the state of Iowa which do not have Class I aggregate readily available for asphalt concrete road construction. The cost of transporting higher quality aggregate specified in the "Standard Specifications for Highway and Bridge construction"' for construction projects is escalating on a yearly basis. Many counties will be squeezed out of the construction of new roadways if an alternative to the high costs is not identified. The same high costs will curtail adequate upkeep on the existing paved system and will result in decreased serviceability. For this reason, a product is needed to better utilize the local aggregates for road construction and maintenance. There i s a product on the market which the promoters claim will improve the prer?nt asphalt to such a degree as to "upgrade deficient aggregates" to the level they can be used in today's standard construction techniques. This product is "Chem-Crete Bitumen," a'kpecially refined asphalt" that was promoted by Chem-Crete Corporation of Menlo Park, California. Chemkrete Technologies, Inc. of Wickliffe, Ohio; a wholly owned subsidiary of the Lubrizol Corporation has since purchased the U.S.

Load Ratings For Secondary Bridges Final Report Highway Research Advisory Board Project HR-239, May 1991

Load Rating: . , :Evaluation of the capacity of a bridge to carry vehicle Inventory Rating: Lbad level which can safely utilize the bridge for an indefinite period of time Operating Rating: Absolute maximum permissible load level for the bridge A load rating states the load in tons which a vehicle can impose on a bridge. Changes in guidelines, standards, and customary uses of bridges require analyses of bridges to be updated and re-evaluated. In this report, twenty-two secondary bridge standards for three types of bridges are rated for the AASHTO HS20-44 vehicle configuration and three typical Iowa legal vehicles

Engineering Study for Reducing Sign Vandalism Final Report Highway Research Advisory Board Projec HR 246, June 1992

Sign vandalism has traditionally been a vexing problem for Iowa counties. The extent of the cost and incidence of these acts have never been fully ascertained, but a 1990 survey indicated that they cost Iowa counties more than 1.5 million dollars annually. In 1990, the Iowa Legislature recognized the seriousness of the problem and strengthened the existing sign vandalism law by increasing the penalty for illegal possession of a traffic control device from a simple to a serious misdemeanor. However, the courts must be willing to prosecute vandals to the magnitude provided in the Iowa Code. An educational campaign begun in 1987 involving over 200 Iowa school districts to educate students on the seriousness of the problem evidently did not have the effect of dramatically reducing the overall cost of sign vandalism in Iowa. This study sought to define the scope of the problem and possibly offer some effective countermeasures to combat sign vandalism and theft in Iowa.

Evaluation of Microcracking and Chemical Deterioration in Concrete Pavements Final Report, October 31, 1995

The major objective of this research project was to investigate the chemistry and morphology of portland cement concrete pavements in Iowa. The integrity of the various pavements was evaluated qualitatively, based on the presence or absence of microcracks, the presence or absence of sulfate minerals, and the presence or absence of alkali-silica gel(s). Major equipment delays and subsequent equipment replacements resulted in significant delays over the course of this research project. However, all these details were resolved and the equipment is currently in place and fully operational. The equipment that was purchased for this project included: ( I ) a LECO VP 50, 12-inch diameter, variable speed grinder/polisher: (2) a Hitachi S-2460N variable pressure scanning electron microscope; and (3) a OXFORD Instruments Link ISIS microanalysis system with a GEM (high-purity germanium) X-ray detector. This study has indicated that many of the concrete pavements contained evidence of multiple deterioration mechanisms: and hence, the identification of a single reason for the distress that was observed in any given pavement typically had to be based on opinion rather than empirical evidence.

Development of a Model for the Ice Scraping Process Iowa Department of Transportation Project HR 361 Final Report, October 1996

A laboratory study has been conducted with two aims in mind. The first goal was to develop a description of how a cutting edge scrapes ice from the road surface. The second goal was to investigate the extent, if any, to which serrated blades were better than un-serrated or "classical" blades at ice removal. The tests were conducted in the Ice Research Laboratory at the Iowa Institute of Hydraulic Research of the University of Iowa. A specialized testing machine, with a hydraulic ram capable of attaining scraping velocities of up to 30 m.p.h. was used in the testing. In order to determine the ice scraping process, the effects of scraping velocity, ice thickness, and blade geometry on the ice scraping forces were determined. Higher ice thickness lead to greater ice chipping (as opposed to pulverization at lower thicknesses) and thus lower loads. S~milabr ehavior was observed at higher velocities. The study of blade geometry included the effect of rake angle, clearance angle, and flat width. The latter were found to be particularly important in developing a clear picture of the scraping process. As clearance angle decreases and flat width increases, the scraping loads show a marked increase, due to the need to re-compress pulverized ice fragments. The effect of serrations was to decrease the scraping forces. However, for the coarsest serrated blades (with the widest teeth and gaps) the quantity of ice removed was significantly less than for a classical blade. Finer serrations appear to be able to match the ice removal of classical blades at lower scraping loads. Thus, one of the recommendations of this study is to examine the use of serrated blades in the field. Preliminary work (by Nixon and Potter, 1996) suggests such work will be fruitful. A second and perhaps more challenging result of the study is that chipping of ice is more preferable to pulverization of the ice. How such chipping can be forced to occur is at present an open question.

Automated Recording of Bridge Inspection Data in the Pontis Format Final Report, HR-364 April 1995

A large percentage of bridges in the state of Iowa are classified as structurally or fiinctionally deficient. These bridges annually compete for a share of Iowa's limited transportation budget. To avoid an increase in the number of deficient bridges, the state of Iowa decided to implement a comprehensive Bridge Management System (BMS) and selected the Pontis BMS software as a bridge management tool. This program will be used to provide a selection of maintenance, repair, and replacement strategies for the bridge networks to achieve an efficient and possibly optimal allocation of resources. The Pontis BMS software uses a new rating system to evaluate extensive and detailed inspection data gathered for all bridge elements. To manually collect these data would be a highly time-consuming job. The objective of this work was to develop an automated-computerized methodology for an integrated data base that includes the rating conditions as defined in the Pontis program. Several of the available techniques that can be used to capture inspection data were reviewed, and the most suitable method was selected. To accomplish the objectives of this work, two userfriendly programs were developed. One program is used in the field to collect inspection data following a step-by-step procedure without the need to refer to the Pontis user's manuals. The other program is used in the office to read the inspection data and prepare input files for the Pontis BMS software. These two programs require users to have very limited knowledge of computers. On-line help screens as well as options for preparing, viewing, and printing inspection reports are also available. The developed data collection software will improve and expedite the process of conducting bridge inspections and preparing the required input files for the Pontis program. In addition, it will eliminate the need for large storage areas and will simplify retrieval of inspection data. Furthermore, the approach developed herein will facilitate transferring these captured data electronically between offices within the Iowa DOT and across the state.

Evaluation of Bond Retainage in Portland Cement Concrete Overlays Using Infrared Thermography and Ground Penetrating Radar, HR-537, Final Report, 1989

When concrete deterioration begins to occur in highway pavement, repairs become necessary to assure the rider safety, extend its useful life and restore its riding qualities. One rehabilitation technique used to restore the pavement to acceptable highway standards is to apply a thin portland cement concrete (PCC) overlay to the existing pavement. First, any necessary repairs are made to the existing pavement, the surface is then prepared, and the PCC overlay is applied. Brice Petrides-Donohue, Inc. (Donohue) was retained by the Iowa Department of Transportation (IDOT) to evaluate the present condition with respect to debonding of the PCC overlay at fifteen sites on Interstate 80 and State Highway 141 throughout the State of Iowa. This was accomplished by conducting an infrared thermographic and ground penetrating radar survey of these sites which were selected by the Iowa Department of Transportation. The fifteen selected sites were all two lanes wide and one-tenth of a mile long, for a total of three lane miles or 190,080 square feet. The selected sites are as follows: On Interstate 80 Eastbound, from milepost 35.25 to 35.35, milepost 36.00 to 36.10, milepost 37.00 to 37.10, milepost 38.00 to 38.10 and milepost 39.00 to 39.10, on State Highway 141 from milepost 134.00 to 134.10, milepost 134.90 to milepost 135.00, milepost 135.90 to 136.00, milepost 137.00 to 137.10 and milepost 138.00 to 138.10, and on Interstate 80 Westbound from milepost 184.00 to 184.10, milepost 185.00 to 185.10, milepost 186.00 to 186.10, milepost 187.00 to 187.10, and from milepost 188.00 to 188.10.

Evauation of Recycled Asphalt Concrete Pavements: Final Report for Kossuth County, Iowa, HR-1888, February 1980

After some success with a small asphalt pavement recycling project in 1975, Kossuth County, Iowa programmed a much larger undertaking during the 1976 construction season. The work performed in 1975 indicated that a quality product could be produced with some modifications to conventional equipment. As anticipated , the major problem encountered was the excessive air pollution created during the heating and mixing process. As part of its 1976 road program, Kossuth County developed plans for recycling sixteen miles of existing asphalt pavements using the "hot mix" recycling process. One project, ten miles in length, was selected by the Federal Highway Authority as part of "Demonstration Project No. 39, Recycling Asphalt Pavements." The FHWA provided a $29,500 grant t o the project to be used for project testing and evaluation. Cooperation and input into the work proposed for 1976 was received from many sources. The people and organizations contributing were the Federal Highway Authority, the Iowa Department of Environmental Quality, the Federal Environmental Protection Agency, several contractors, and personnel from the Kossuth County Engineer's Office.

Final Report Factors Influencing Stability of Granular Base Course Mixes

To evaluate the various factors influencing the stability of granular base course mixes, three primary goals were included in the project: (1) determination of a suitable and realistic laboratory method of compaction; (2) effect of gradation, density and mineralogy of the fines on sheara ing strength; and (3) possible improvement of the shear strength with organic and inorganic chemical stabilization additives.

NLG Museum Connecting to Collections, Statewide Planning Grant, Developing a Statewide Disaster Preparedness and Response Plan for Iowa, Final report.

The Iowa Conservation and Preservation Consortium, Iowa Museum Association, the State Historical Society of Iowa and the State Library requested the IMLS CTC grant funds so we could develop a statewide plan to help the stewards of cultural property plan for protection and disaster recovery of collections. We are very pleased with the results of our grant activities. Thanks to the IMLS CTC grant over 200 Iowa collection care takers have received basic training in disaster preparedness and response, 24 care takers have signed up to become cultural collection first responders, a dozen disaster planning/response trainers are available upon request, and over 40 institutions have ReAct Paks. We have created a variety of training tools ranging from basic awareness to in-depth training, established a website of disaster resources, and geo-referenced hundreds of cultural collection sites around Iowa. In addition, the IMLS grant was just the motivator we needed to participate in other national/international efforts which in turn strengthened our IMLS grant project.

Evaluating the Effectiveness of Red Light Running Camera Enforcement in Cedar Rapids and Developing Guidelines for Selection and Use of Red Light Running Countermeasures Final Report, November 2011

Red light running (RLR) is a problem in the US that has resulted in 165,000 injuries and 907 fatalities annually. In Iowa, RLR-related crashes make up 24.5 percent of all crashes and account for 31.7 percent of fatal and major injury crashes at signalized intersections. RLR crashes are a safety concern due to the increased likelihood of injury compared to other types of crashes. One tool used to combat red light running is automated enforcement in the form of RLR cameras. Automated enforcement, while effective, is often controversial. Cedar Rapids, Iowa installed RLR and speeding cameras at seven intersections across the city. The intersections were chosen based on crash rates and whether cameras could feasibly be placed at the intersection approaches. The cameras were placed starting in February 2010 with the last one becoming operational in December 2010. An analysis of the effect of the cameras on safety at these intersections was determined prudent in helping to justify the installation and effectiveness of the cameras. The objective of this research was to assess the safety effectiveness of the RLR program that has been implemented in Cedar Rapids. This was accomplished by analyzing data to determine changes in the following metrics: ï‚· Reductions in red light violation rates based on overall changes, time of day changes, and changes by lane ï‚· Effectiveness of the cameras over time ï‚· Time in which those running the red light enter the intersection ï‚· Changes in the average headway between vehicles entering the intersection

Toolbox of Countermeasures to Reduce Red Light Running Final Report, April 2012

Red light running (RLR) is a problem in the US that has resulted in 165,000 injuries and 907 fatalities annually. In Iowa, RLR-related crashes make up 24.5 percent of all crashes and account for 31.7 percent of fatal and major injury crashes at signalized intersections. RLR crashes are a safety concern due to the increased likelihood of injury compared to other types of crashes. The research team developed this toolbox for practitioners to address RLR crashes. The Four Es—Engineering, Enforcement, Education, and Emergency Response—should be used together to address RLR problems. However, this toolbox focuses on engineering, enforcement, and education solutions. The toolbox has two major parts:  Guidelines to identify problem intersections and the causes of RLR at intersections  Roadway-based and enforcement countermeasures for RLR

Evaluation of Rumble Stripes on Low-Volume Rural Roads in Iowa—Phase II Final Report, November 2011

Single-vehicle run-off-road crashes are the most common crash type on rural two-lane Iowa roads. Rumble strips have proven effective in mitigating these crashes, but the strips are commonly installed in paved shoulders on higher-volume roads that are owned by the State of Iowa. Lower-volume paved rural roads owned by local agencies do not commonly feature paved shoulders but frequently experience run-off-road crashes. This project involved installing rumble stripes, which are a combination of conventional rumble strips with a painted edge line placed on the surface of the milled area, along the edge of the travel lanes, but at a narrow width to avoid possible intrusion into the normal vehicle travel paths. The research described in this report was part of a project funded by the Federal Highway Administration, Iowa Highway Research Board, and Iowa Department of Transportation to evaluate the effectiveness of edge-line rumble strips in Iowa. The project evaluated the effectiveness of rumble stripes in reducing run-off-road crashes and in improving the longevity and wet-weather visibility of edge-line markings. This project consisted of two phases. The first phase was to select pilot study locations, select a set of test sites, install rumble stripes, summarize lessons learned during installation, and provide a preliminary assessment of the rumble stripes’ performance. The purpose of this report was to document results from Phase II. A before and after crash analysis was conducted to assess whether use of the treatment had resulted in fewer crashes. However, due to low sample size, results of the analysis were inconclusive. Lateral position was also evaluated before and after installation of the treatment to determine whether vehicles engaged in better lane keeping. Pavement marking wear was also assessed.