Stability of Granular Base Course Materials Containing Bituminous Admixtures

This report concerns the stabilization of three crushed limestones by an ss-1 asphalt emulsion and an asphalt cement, 120-150 penetration. Stabilization is evaluated by marshall stability and triaxial shear tests. Test specimens were compacted by the marshall, standard proctor and vibratory methods. Stabilization is evaluated primarily by triaxial shear tests in which confining pressures of 0 to 80 psi were used. Data were obtained on the angle of internal friction, cohesion, volume change, pore water pressure and strain characteristics of the treated and untreated aggregates. The MOHR envelope, bureau of reclamation and modified stress path methods were used to determine shear strength parameters at failure. Several significant conclusions developed by the authors are as follows: (1) the values for effective angle of internal friction and effective cohesion were substantially independent of asphalt content, (2) straight line MOHR envelopes of failure were observed for all treated stones, (3) bituminous admixtures did little to improve volume change (deformation due to load) characteristics of the three crushed limestones, (4) with respect to pore water characteristics (pore pressures and suctions due to lateral loading), bituminous treatment notably improved only the bedford stone, and (5) at low lateral pressures bituminous treatments increased stability by limiting axial strain. This would reduce rutting of highway bases. At high lateral pressures treated stone was less stable than untreated stone.

U. S. 61 Muscatine Bypass Corridor

This report was prepared for the Iowa Department of Transportation to document the results of a comprehensive study of the US 61 bypass corridor in Muscatine, Iowa. The focus of the study was to address community concerns regarding traffic safety and traffic operations. In completing the study, accident and traffic volume data was collected and analyzed. Input from the public and elected officials of the Muscatine community was also obtained. The goals of the project were to: Accurately identify the nature of the types of problems and the locations where the problems were occurring; Formulate a range of possible remedial measures; Analyze and test those proposed measures; Inform the community of the nature of the traffic problems and of the proposed remedies; Seek feedback from the community on those proposed remedies; Develop a comprehensive list of recommended improvements; Develop cost estimates and assign priorities to those possible improvements. An additional goal of this project was to identify possible Intelligent Transportation System (ITS) measures that could be used to address the safety and operations problems that have developed along this corridor. The proposed ITS measures were also to be analyzed to determine their likely benefits and their likely success if used at other locations elsewhere in Iowa.

50 Years of Highway Maintenance

An overview of the first 50 years of the Iowa State Highway Commission.

1999 Highway Accomplishment Program, Draft, 1999

A list of proposed or added project to the 1999 Highway Accomplishment Program

Frost Boils, 1961

Paper on frost boils presented at the 6th Annual Asphalt Paving Conference.

Highway 60 Reconstruction Project : Final Environmental Impact Statement, 2004

The proposed reconstruction of Trunk Highway 60 is considered a Federal Class I Action because of the potential for significant impacts on the natural and physical environment. An Environmental Impact Statement (EIS) is a full disclosure document that discusses the environmental impacts of a proposed Class I action. The Draft EIS, which was distributed in July 2002, is incorporated by reference herein and made a part of the Final EIS.

Highway Location Reference Procedure Project, 1990

The purpose of the proposed Highway Location Reference Procedure is stated in the contract as follows: "Establishment of a highway network locational reference process that will primarily allow for the proper correlation of pavement management data, and secondarily provide the basis for other existing and future data base integration and for the planned Iowa DOT Geographic Information System. In addition, the locational reference process will be able to correlate network applications with a statewide spatial location method to facilitate the relationship of Iowa DOT data to that of other agencies and to allow for the graphic display of the network in map form." The Design Specifications and Implementation Plan, included in this Final Report, are intended to provide the basis for proceeding with immediate development and implementation of the pavement management system. These specifications will also support the future Iowa DOT implementation of other integrated data bases and/or the planned Geographic Information System.

Iowa Statewide Highway Transportation Study: Trip Data Analysis, Vol. 1-D, 1974

The object of this report is to present the data and conclusions drawn from the analysis of the origin and destination information. Comments on the advisability and correctness of the approach used by Iowa are encouraged.

Iowa's Highways, 1950

A brief history of Iowa highways.

Preliminary Assessment of the Potential Use of Alternative Materials for Concrete Highway Pavement Joints, 1997

The overall objective of the work contained in this paper is to identify background information on the use of load-transfer devices in highway pavement joints and to provide a preliminary assessment of the market potential for use of alternative materials in that capacity. The intent of the authors is to provide a concise compilation of information upon which HITEC personnel may judge whether or not the use of alternative materials for concrete highway pavement joints is worth a more thorough and rigorous evaluation.

Primary Road Bonds, 1950

A brief overview of Iowa's road bonds.

U.S. 63 Corridor Study, 1992

This report describes the U.S. 63 Corridor in terms of its economic and demographic features, the physical characteristics of the existing facility and the traffic it serves. Also, the various improvement alternatives are described and evaluated. These evaluations consider the traffic needs in the time period up to the year 2010, the travel benefits that would derive from alternative improvements to U.S. 63 and the economic development benefits that would be stimulated by such improvements. These benefits are related to the costs of the improvements and various indicators of economic feasibility are provided.

U.S. Highway 20 Corridor Development Study - Report C: Final Screening of Alternative Candidate Improvements, 1992

This report briefly compares the alternative improvement options using analyses conducted to date, and is intended to identify the alternatives which should be carried forward into the study's economic evaluation phase.

Roadside erosion research in selected Iowa counties, 1972

This research project discusses roadside stabilization along secondary roads. Another objective was to investigate various commercial soil stabilizers, as a replacement for straw mulch, to control soil erosion before vegetation.

Evaluation of fly ash in water reduced paving mixtures, 1984

Fly ash was used to replace 15% of the cement in C3WR and C6WR concrete paving mixes containing ASTM C494 Type A water reducin9 admixtures. Two Class C ashes and one Class F ash from Iowa approved sources were examined in each mix. When Class C ashes were used they were substituted on the basis of 1 pound of ash added for each pound of cement deleted. When Class F was used it was substituted on the basis of 1.25 pounds of ash added for each pound of cement deleted. Compressive strengths of the water reduced mixes, with and without fly ash, were determined at 7, 28, and 56 days of age. In every case except one the mixes containing the fly ash exhibited higher strengths than the same concrete mix without the fly ash. An excellent correlation existed between the C3WR and C6WR mixes both with and without fly ash substitutions. The freeze-thaw durability of the concrete studied was not affected by presence or absence of fly ash. The data gathered suggests that the present Class C water reduced concrete paving mixes can be modified to allow the substitution of 15% of the cement with an approved fly ash.