Investigation of the Modified Beam-in-Slab Bridge System, Design Manual, 2004, Vol. 2

Design Manual

Report on Special Investigation of the City of Liscomb, For the Period June 1, 2002 through November 30, 2004

City Audit Report - Special Investigation

Report on Special Investigation of Before and After School Services, For the Period July 1, 2000 through December 31, 2004

Other Audit Reports - Special Investigation

Report on the Special Investigation of the City of Mt. Vernon Fire Department, For the Period January 1, 2003 through March 31, 2005

Other Audit Reports - Special Investigation

An Investigation of User Costs and Benefits of Winter Road Closures, June 2005

This project explores the user costs and benefits of winter road closures. Severe winter weather makes travel unsafe and dramatically increases crash rates. When conditions become unsafe due to winter weather, road closures should allow users to avoid crash costs and eliminate costs associated with rescuing stranded motorists. Therefore, the benefits of road closures are the avoided safety costs. The costs of road closures are the delays that are imposed on motorists and motor carriers who would have made the trip had the road not been closed. This project investigated the costs and benefits of road closures and found that evaluating the benefits and costs is not as simple as it appears. To better understand the costs and benefits of road closures, the project investigates the literature, conducts interviews with shippers and motor carriers, and conducts case studies of road closures to determine what actually occurred on roadways during closures. The project also estimates a statistical model that relates weather severity to crash rates. Although, the statistical model is intended to illustrate the possibility to quantitatively relate measurable and predictable weather conditions to the safety performance of a roadway. In the future, weather conditions such as snow fall intensity, visibility, etc., can be used to make objective measures of the safety performance of a roadway rather than relying on subjective evaluations of field staff. The review of the literature and the interviews clearly illustrate that not all delays (increased travel time) are valued the same. Expected delays (routine delays) are valued at the generalized costs (value of the driver’s time, fuel, insurance, wear and tear on the vehicle, etc.), but unexpected delays are valued much higher because they result in interruption of synchronous activities at the trip’s destination. To reduce the costs of delays resulting from road closures, public agencies should communicate as early as possible the likelihood of a road closure.

Special Investigation Letter to Jones County, March 8, 2005

County Audit Report - Special Investigation Letter

Investigation into Improved Pavement Curing Materials and Techniques: Part 2 - Phase III, March 2003

Appropriate curing is important for concrete to obtain the designed properties. This research was conducted to evaluate the curing effects of different curing materials and methods on pavement properties. At present the sprayed curing compound is a common used method for pavement and other concrete structure construction. Three curing compounds were selected for testing. Two different application rates were employed for the white-pigmented liquid curing compounds. The concrete properties of temperature, moisture content, conductivity, and permeability were examined at several test locations. It was found, in this project, that the concrete properties varied with the depth. Of the tests conducted (maturity, sorptivity, permeability, and conductivity), conductivity appears to be the best method to evaluate the curing effects in the field and bears potential for field application. The results indicated that currently approved curing materials in Iowa, when spread uniformly in a single or double application, provide adequate curing protection and meet the goals of the Iowa Department of Transportation. Experimental curing methods can be compared to this method through the use of conductivity testing to determine their application in the field.

Report on Special Investigation of the Rural Iowa Waste Management Association for the Period July 1st, 1999 through October 15th, 2004

Other Audit Reports - Special Investigation

Report on Special Investigation of the Keokuk County Information Technology Department, For the Period October 14, 2002 through March 14, 2005

Other Audit Reports - Special Investigation

Report on Special Investigation of the City of Valeria, For the Period January 1, 2004 through August 31, 2005

Other Audit Reports - Special Investigation

Report on Special Investigation of the Cedar County Economic Development Commission, For the Period December 1, 2000 through July 31, 2005

Other Audit Reports - Special Investigation

Utility Cut Repair Techniques— Investigation of Improved Cut Repair Techniques to Reduce Settlement in Repaired Areas, December 2005

Pavement settlement occurring in and around utility cuts is a common problem, resulting in uneven pavement surfaces, annoyance to drivers, and ultimately, further maintenance. A survey of municipal authorities and field and laboratory investigations were conducted to identify the factors contributing to the settlement of utility cut restorations in pavement sections. Survey responses were received from seven cities across Iowa and indicate that utility cut restorations often last less than two years. Observations made during site inspections showed that backfill material varies from one city to another, backfill lift thickness often exceeds 12 inches, and the backfill material is often placed at bulking moisture contents with no Quality control/Quality Assurance. Laboratory investigation of the backfill materials indicate that at the field moisture contents encountered, the backfill materials have collapse potentials up to 35%. Falling Weight Deflectometer (FWD) deflection data and elevation shots indicate that the maximum deflection in the pavement occurs in the area around the utility cut restoration. The FWD data indicate a zone of influence around the perimeter of the restoration extending two to three feet beyond the trench perimeter. The research team proposes moisture control, the use of 65% relative density in a granular fill, and removing and compacting the native material near the ground surface around the trench. Test sections with geogrid reinforcement were also incorporated. The performance of inspected and proposed utility cuts needs to be monitored for at least two more years.

Report on Special Investigation of the Lee County Protective Payee Program, For the Period September 1, 2001 through February 1, 2005

Other Audit Reports - Special Investigation

Report on Special Investigation of the Boone Community School District, For the Period July 1, 2001 through November 30, 2005

Other Audit Reports - Special Investigation

Report on Special Investigation of the City of Reasnor, For the Period of May 1, 2005 through December 31, 2005

Other Audit Reports - Special Investigation