Road Equipment Procurement and Utilization Study, October 2002

Final report of road equipment procurement and utilization study.

Investigation of the Department Human Services' handling of allegations of child abuse concerning Shelby Duis, 2000

Investigative report produced by Iowa Citizens' Aide/Ombudsman

Evalution of Hot Mix Asphalt Moisture Sensitivity Using the Nottingham Asphalt Test Equipment, July 2005

Moisture sensitivity of Hot Mix Asphalt (HMA) mixtures, generally called stripping, is a major form of distress in asphalt concrete pavement. It is characterized by the loss of adhesive bond between the asphalt binder and the aggregate (a failure of the bonding of the binder to the aggregate) or by a softening of the cohesive bonds within the asphalt binder (a failure within the binder itself), both of which are due to the action of loading under traffic in the presence of moisture. The evaluation of HMA moisture sensitivity has been divided into two categories: visual inspection test and mechanical test. However, most of them have been developed in pre-Superpave mix design. This research was undertaken to develop a protocol for evaluating the moisture sensitivity potential of HMA mixtures using the Nottingham Asphalt Tester (NAT). The mechanisms of HMA moisture sensitivity were reviewed and the test protocols using the NAT were developed. Different types of blends as moisture-sensitive groups and non-moisture-sensitive groups were used to evaluate the potential of the proposed test. The test results were analyzed with three parameters based on performance character: the retained flow number depending on critical permanent deformation failure (RFNP), the retained flow number depending on cohesion failure (RFNC), and energy ratio (ER). Analysis based on energy ratio of elastic strain (EREE ) at flow number of cohesion failure (FNC) has higher potential to evaluate the HMA moisture sensitivity than other parameters. If the measurement error in data-acquisition process is removed, analyses based on RFNP and RFNC would also have high potential to evaluate the HMA moisture sensitivity. The vacuum pressure saturation used in AASHTO T 283 and proposed test has a risk to damage specimen before the load applying.

Iowa Department of Transportation; Equipment and Vehicle Purchase Report for Fiscal Year 2007

This is the Iowa Department of Transportation's Equipment and Vehicle Purchase Report for Fiscal Year 2007 as required by Iowa Code section 307.47. The report is sorted by our accounting object codes.

Equipment and Vehicle Purchase Report, 2008

Attached is the Equipment and Vehicle Purchase Report for Fiscal Year 2008 as required by Iowa Code section 307.47. The report is sorted by our accounting object codes. The object codes help you sort the equipment into general categories. The following list will help you understand the codes: Object Description 701 Self Propelled Vehicles 702 Road Equipment & Trailers 703 Large Office Furniture & Files 704 Shop Tools & Small Equipment 705 Engineer, Survey & Measuring Equipment 706 Copiers, Fax & Communication Equipment 707 Computers & Related Equipment

River Barge Terminal Directory, July 2005

The Barge Terminal Directory has been prepared by the Iowa Department of Transportation’s Modal Division to provide quick access to information on Iowa’s river terminals and fleeting/harbor services. The information is to assist those who may need barge transportation services. The information in the directory was provided by the terminal operators. The Modal Division would appreciate any help on corrections, additions or deletions.

The impact of restricting beverage container use in Iowa, 1/1/77.

Suzan M. Stewart, Research Librarian, Iowa Geological Survey. and Edward J. Stanek II, Director, Air Management Division, Iowa Department of Environmental Quality

Equipment and Vehicle Purchase Report for Fiscal Year 2009

Attached is the Equipment and Vehicle Purchase Report for Fiscal Year 2009 as required by Iowa Code section 307.47. The report is sorted by Iowa Department of Transportation accounting object codes.

Equipment and Vehicle Purchase Report for Fiscal Year 2009 as required by Iowa Code section 307.47

Attached is the Equipment and Vehicle Purchase Report for Fiscal Year 2009 as required by Iowa Code section 307.47. The report is sorted by Iowa Department of Transportation accounting object codes.

Iowa Code Section 307.47 Equipment and Vehicle Report

Attached is the Iowa Department of Transportation's Equipment and Vehicle Purchase Report for Fiscal Year 2010 as required by Iowa Code section 307.47.

Equipment and Vehicle Purchase Report for Fiscal Year 2011, January 13,2 012

Attached is the Equipment and Vehicle Purchase Report for Fiscal Year 2011 as required by Iowa Code section 307.47. The report is sorted by accounting object codes. The object codes help sort the equipment into general categories.

Evaluation of Hot Mix Asphalt Moisture Sensitivity Using the Nottingham Asphalt Test Equipment, July 2005

Moisture sensitivity of Hot Mix Asphalt (HMA) mixtures, generally called stripping, is a major form of distress in asphalt concrete pavement. It is characterized by the loss of adhesive bond between the asphalt binder and the aggregate (a failure of the bonding of the binder to the aggregate) or by a softening of the cohesive bonds within the asphalt binder (a failure within the binder itself), both of which are due to the action of loading under traffic in the presence of moisture. The evaluation of HMA moisture sensitivity has been divided into two categories: visual inspection test and mechanical test. However, most of them have been developed in pre-Superpave mix design. This research was undertaken to develop a protocol for evaluating the moisture sensitivity potential of HMA mixtures using the Nottingham Asphalt Tester (NAT). The mechanisms of HMA moisture sensitivity were reviewed and the test protocols using the NAT were developed. Different types of blends as moisture-sensitive groups and non-moisture-sensitive groups were used to evaluate the potential of the proposed test. The test results were analyzed with three parameters based on performance character: the retained flow number depending on critical permanent deformation failure (RFNP), the retained flow number depending on cohesion failure (RFNC), and energy ratio (ER). Analysis based on energy ratio of elastic strain (EREE ) at flow number of cohesion failure (FNC) has higher potential to evaluate the HMA moisture sensitivity than other parameters. If the measurement error in data-acquisition process is removed, analyses based on RFNP and RFNC would also have high potential to evaluate the HMA moisture sensitivity. The vacuum pressure saturation used in AASHTO T 283 and proposed test has a risk to damage specimen before the load applying.

FY 2012 Equipment and Vehicle Revolving Fund report

The Equipment and Vehicle Revolving Fund report covers all equipment and vehicle purchases through the highway materials and equipment revolving fund during FY 2012.

FY 2013 Equipment and Vehicle Revolving Fund report

The Equipment and Vehicle Revolving Fund report covers all equipment and vehicle purchases through the highway materials and equipment revolving fund during FY 2013.

Control of Concrete Deterioration Due to Trace Compounds in Deicers, Phase II, HR-299, 1989

This report presents results of research on ways to reduce the detrimental effects of sulfate-tainted rock salt deicers on portland cement concrete used for highway pavements. Repetitious experiments on the influence of fly ash on the mortar phase of concrete showed significant improvement in resistance to deicing brines is possible. Fifteen to twenty percent by weight of fly ash replacement for portland cement was found to provide optimum improvement. Fly ashes from five sources were evaluated and all were found to be equally beneficial. Preliminary results indicate the type of coarse aggregate also plays an important role in terms of concrete resistance to freeze-thaw in deicing brines. This was particularly true for a porous ferroan dolomite thought to be capable of reaction with the brine. In this case fly ash improved the concrete, but not enough for satisfactory performance. An intermediate response was with a porous limestone where undesirable results were observed without fly ash and adequate performance was realized when 15% fly ash was added. The best combination for making deicer-resistant concrete was found to be with a non-porous limestone. Performance in brines was found to be adequate without fly ash, but better when fly ash was included. Consideration was given to treating existing hardened concrete made with poor aggregate and no fly ash to extend pavement life in the presence of deicers, particularly at joints. Sodium silicate was found to improve freeze-thaw resistance of mortar and is a good candidate for field usage because of its low cost and ease of handling.