Lime or Chloride Treatment of Granular Base Course Materials, HR-99

Results are presented of triaxial testing of three crushed limestones to which either hydrated high-calcium lime, sodium chloride or calcium chloride had been added. Lime was added at rates of 1, 3, 10 and 16 percent, chlorides were added at 0.5 percent rate only. Speciments were compacted using vibratory compaction apparatus and were tested in triaxial compression using lateral pressures from 10 to 100 psi. Triaxial test results indicate that: (1) sodium chloride slightly decreased the angle of internal friction and increased cohesion, (2) calcium chloride slightly increased the angle of internal friction and decreased cohesion, and (3) lime had no appreciable effect on angle of internal friction but increased cohesion, decreased density and increased pore water pressure.

Improvement of Granular Base Course Materials with Portland Cement, Special Report, HR-99

A highway base course may be defined as a layer of granular material which lies immediately below the wearing surface of a pavement and must possess high resistance to deformation in order to withstand pressures imposed by traffic. A material commonly used for base course construction is crushed limestone. Sources of limestone, acceptable for highway bases in the state of Iowa, occur almost entirely in the Pennsylvanian, Mississippian and Devonian strata. Performance records of the latter two have been quite good, while material from the Pennsylvanian stratum has failed on numerous occasions. The study reported herein is one segment of an extensive research program on compacted crushed limestone used for flexible highway base courses. The primary goals of the total study are: 1. Determination of a suitable and realistic laboratory method of compaction. 2. Effect of gradation, and mineralogy of the fines, on shearing strength. 3. Possible improvement of the shear strength with organic and inorganic chemical stabilization additives. Although the study reported herein deals primarily with the third goal, information gathered from work on the first two was required for this investigation. The primary goal of this study was the evaluation of various factors of stability of three crushed limestones when treated with small amounts of type I Portland cement. Investigation of the untreated materials has indicated that shear strength alone is not the controlling factor for stability of crushed stone bases. Thus the following observations were made in addition to shear strength parameters, to more adequately ascertain the stability of the cement treated materials: 1. Volume change during consolidation and shear testing. 2. Pore pressure during shear. The consolidated-undrained triaxial shear test was used for determination of the above factors.

Iowa Historic Property Study of the Zeman Barn, 2009

The Zeman Barn (86-00028) is an early twentieth-century example of a gothic roofed barn and is part of the Zeman Farmstead located along U.S. Highway 30 in Otter Creek Township (Township 38N, Range 14W), Tama County, Iowa (Figures 1 and 2). The farmstead was initially evaluated in a reconnaissance architectural survey conducted in 1998 by The Louis Berger Group, Inc (Berger). An intensive architectural survey of the property by Berger’s Principal Architectural Historian, Martha H. Bowers, evaluated the farmstead as not being eligible for listing in the National Register of Historic Places (National Register) but noted that the barn appears to be eligible for listing in the National Register under Criterion C (Bowers 1998). At the request of the Iowa Department of Transportation, Berger completed the recordation project to provide a documentary record of the Zeman Barn in accordance with the guidelines set forth by the Iowa State Historic Preservation Office regarding historic property studies for barns. Background research for this project was conducted in September 2008 and April 2009. The property was inspected and photographed in May 2008. Information on the property was gathered through background research, interviews with Zeman family members, field investigation, and photo documentation. Historical maps of the project area were used to collect data necessary for developing regional and local historic contexts. The research for this report was conducted at the Tama County Courthouse and the Tama County Historical Museum Genealogical Library, both in Toledo. Much of the background research for the project was conducted by Camilla Deiber and Michael Dulle. Ms. Deiber also prepared the photographic documentation, plan drawings, and the graphics used in this report. Mr. Roger L. Ciuffo conducted interviews with Zeman family members and wrote this report.

Optimizing Pavement Base, Subbase, and Subgrade Layers for Cost and Performance of Local Roads, TR-640

This report is one of two products for this project with the other being a design guide. This report describes test results and comparative analysis from 16 different portland cement concrete (PCC) pavement sites on local city and county roads in Iowa. At each site the surface conditions of the pavement (i.e., crack survey) and foundation layer strength, stiffness, and hydraulic conductivity properties were documented. The field test results were used to calculate in situ parameters used in pavement design per SUDAS and AASHTO (1993) design methodologies. Overall, the results of this study demonstrate how in situ and lab testing can be used to assess the support conditions and design values for pavement foundation layers and how the measurements compare to the assumed design values. The measurements show that in Iowa, a wide range of pavement conditions and foundation layer support values exist. The calculated design input values for the test sites (modulus of subgrade reaction, coefficient of drainage, and loss of support) were found to be different than typically assumed. This finding was true for the full range of materials tested. The findings of this study support the recommendation to incorporate field testing as part of the process to field verify pavement design values and to consider the foundation as a design element in the pavement system. Recommendations are provided in the form of a simple matrix for alternative foundation treatment options if the existing foundation materials do not meet the design intent. The PCI prediction model developed from multi-variate analysis in this study demonstrated a link between pavement foundation conditions and PCI. The model analysis shows that by measuring properties of the pavement foundation, the engineer will be able to predict long term performance with higher reliability than by considering age alone. This prediction can be used as motivation to then control the engineering properties of the pavement foundation for new or re-constructed PCC pavements to achieve some desired level of performance (i.e., PCI) with time.

Iowa Historic Property Study: Iowa-Illinois Memorial Bridge Carrying I-74 and U.S. 6 over Mississippi River between Bettendorf, Scott County, Iowa and Moline, Rock Island County, Illinois, 2012

The 1935 Iowa-Illinois Memorial Bridge is being documented at this time to fulfill the requirements of the Memorandum of Agreement regarding the removal of the Iowa-Illinois Memorial Bridge and the Iowana Farms Milk Company Building for the proposed improvements to Interstate 7 4 in Bettendorf, Iowa, and Moline, Illinois.1 The 1959 twin suspension bridge will be removed as well, but it was determined to be ineligible for the National Register of Historic Places. Discussion of the history of the 1959 twin span is included, however, in the current report as part of the overall history of the Iowa-Illinois Memorial Bridge. Fieldwork for the documentation occurred in November 2009 and October 2010 (Fig. 1). Limitations on photography included limited shoreline access on the Illinois side, making good views of the bridge from the south somewhat challenging. Also, photographs on the bridge deck were not possible because of interstate traffic and prohibitions on pedestrian traffic. Within the last few years, online primary sources have proliferated, along with historical materials regarding the Iowa-Illinois Memorial Bridge. Sources available online for this report included numerous historical photographs, as well as historical Davenport, Iowa, and U.S. newspapers that document the bridge planning and construction. Additional primary source material was found at the University of Iowa Libraries, the State Historical Society of Iowa in Iowa City, the Bettendorf Public Library, the Richardson-Sloane Special Collections Center at the Davenport Public Library, and the Iowa State University Special Collections in Ames.

Iowa Historic Property Study: Iowana Farms Milk Company, 1416 State Street, City of Bettendorf, Scott County, Iowa, 2012

The Iowana Farms Milk Company factory building was considered to retain sufficient integrity and possess sufficient significance to be considered eligible for the National Register of Historic Places under Criteria A and C for its historical and architectural significance in the Bettendorf community. The Iowana Farms Milk Company was an important early to mid-twentieth-century business in Bettendorf, and was among the few that was not owned or operated by the Bettendorf Company. It was a strong and thriving business for many years, and its products were well known in the Quad Cities region. The importance of this property becomes even more significant when one considers that most of the buildings once associated with the actual Bettendorf Company, which was undeniably the most important business and industry in town, are now gone. As a result, the Iowana Farms Milk Company factory building was a physical vestige of the once-thriving commercial industries that made Bettendorf into a city in the twentieth century. This property was further significant for its representation of the evolution of the dairy industry in the twentieth century from farm to factory production. It also reflected the changes to the industry based on scientific discoveries, mechanical innovations, and governmental regulations related to improved sanitation and the pure milk movement. The Iowana Farms Milk Company represented a model plant for the time, and the marketing strategies it employed followed the trends of the industry. The Iowana Farms Milk Company plant had to be removed to make room for a new I-74 bridge over the Mississippi River at Bettendorf. The construction of the new bridge also required removal of the historic Iowa-Illinois Memorial Bridge. The documentation reported herein and for that of the Iowa-Illinois Memorial Bridge fulfills the requirements of the Memorandum of Agreement regarding the removal of these historic properties.

Thin Asphalt Concrete Pavement on Crushed Rock Base, HR-2075, 2001

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.

Laboratory Study of the Leachate from Crushed Portland Cement Concrete Base Material, MLR-96-04, 1999

Since the 1980s, the Iowa Department of Transportation has increased its use of recycled Portland Cement Concrete (PCC) as drainable base material below some new pavements. Water flowing out of the longitudinal drains on projects having recycled PCC drainable bases was found to have a high pH value. The high pH water impedes vegetation growth and becomes a contributing factor to soil erosion at the drain outlet. In addition, the high pH water contributes to the growth of crystalline deposits on the drain outlet wire mesh rodent guard and in some cases caused it to become completely blocked. This research determined which of three choices of recycled PCC drainable base material, gradation, and design would give the lowest pH value in the drain discharge water. The drainable base material having its fines separated out and placed as a 2-in. (5.1-mm) bottom layer, below the remaining coarse material, generally gave pH values around 11.2 while other designs tested gave pH values around 11.5.

Health consultation : Contamination of sump within residential property, Carroll County, Iowa (2007)

The Iowa Department of Natural Resources (IDNR) has been involved in an investigation surrounding the appearance of an unknown oil within the sump in the basement of a residence in Carroll, Iowa. The IDNR has requested the Iowa Department of Public Health (IDPH) to prepare a health consultation regarding their investigation. The IDPH, in cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR), prepared this health consultation to review the current status of the IDNR investigation and to provide an evaluation of the public health implications of exposure to the unknown oil within the sump. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.

Low Cost Techniques of Base Stabilization, HR-312, Construction Report, 1989

This research project was initiated in 1988 to study the effectiveness of four different construction techniques for establishing a stable base on a granular surfaced roadway. After base stabilization, the roadway was then seal coated, eliminating dust problems associated with granular surfaced roads. When monies become available, the roadway can be surfaced with a more permanent structure. A 2.8 mile section of the Horseshoe Road in Dubuque County was divided into four divisions for the study. This report discusses the procedures used during construction of these different divisions. Problems and possible solutions have been analyzed to better understand the capabilities of the materials and construction techniques used on the project.

Ammonium Phosphate/Fly Ash Road Base Construction, HR-294, Construction Report, 1987

The objective of this research project was to evaluate the construction and service performance of ammonium phosphate/fly ash (APFA) treated base courses of crushed fines and/or unprocessed sand. Specific test results related to construction of the test sections were included in the 1987 construction report by Iowa State University. The performance of the experimental sections is dealt with in this final report. This 1986 project demonstrated that in all cases the control sections utilizing a Type B base experienced dramatically less cracking in the surface than the APFA treated base sections. The cost per mix and subsequent surface maintenance costs for the APFA base sections, especially those having a substantial amount of limestone, were higher than the Type B base control sections. This type of construction may prove to be economical only when petroleum product costs escalate.

Granular Base Materials for Flexible Pavements, HR-131, 1970

The coefficients of relative strength (CORS) of base courses for use in the American association state highway officials (AASHO) interim guide for the design of flexible pavements are determined here. Based on (1) volumetric strain--axial strain relationships at minimum volume, and (2) effective stress ratio-cohesion relationships at maximum effective stress ratio, CORS were determined from the results of laboratory triaxial tests on both asphalt-treated and untreated aggregate base course materials. The researchers conclude that volumetric strain-axial strain at minimum volume appear to be appropriate parameters for determining CORS.

Iowa Development of Rubblized Concrete Pavement Base Mills County, Construction Report, HR-315, 1990

The concept of rubblizing existing concrete pavement prior to the placement of an asphaltic cement concrete overlay has been around for several years and, in fact, has been tried successfully in the states of New York, Michigan, and Ohio. With available construction and maintenance dollars usually not meeting the demands of the needed work, much of the necessary rehabilitation of existing Portland cement concrete pavements is not being completed when it would be most beneficial. Research project HR-315, "Iowa Development of Rubblized Concrete", has been undertaken to determine the effects of rubblized concrete pavement base as it affects the cracking pattern and longevity of the ACC overlay.

Pavement Surface on Macadam Base, Adair County, HR-209, Construction Report, 1980

The objectives were to determine the feasibility and performance of this type of construction and to determine if the macadam base is effective in reducin9or eliminating D-cracking deterioration.