Feasibility Study on Proposed Amtrak service from Chicago, to Iowa City, Iowa via Quad Cities, December 5, 2007

Soon after the Illinois Department of Transportation (“Ill. DOT”) requested Amtrak to conduct a feasibility study on proposed Amtrak service between Chicago and the Illinois Quad Cities, the Iowa Department of Transportation (“Iowa DOT”) asked that the study be extended to Iowa City and later to Des Moines. This report examines the feasibility of extending service to Iowa City. The completed report for the proposed Chicago – Quad Cities’ service was delivered to Ill. DOT in early January 2008. It assumes a stand-alone train operation strictly within the State of Illinois and makes no reference to extending the service into the State of Iowa. Therefore, there is no discussion about potential cost sharing allocations for capital improvements or operating losses between the two states which will become a matter of future negotiations between the two jurisdictions. That being said, this report on extending the service to Iowa City is simply an addendum to the Quad Cities report and covers such topics as additional capital infrastructure improvements that would be required in Iowa, impacts on operating expenses, revised ridership and revenue projections, and the like. With one minor exception, the recommended level of capital improvements within Illinois will still be required if the service to Iowa City is initiated. It is thus important for the readers of this report to refer to the Illinois study for detailed information on that state’s portion of the route alternatives.

A Study to Correlate Soil Consistency Limits with Soil Moisture Tensions, HR-27, 1965

The liquid and plastic limits of a soil are consistency limits that were arbitrarily chosen by Albert Atterberg in 1911. Their determination is by strictly empirical testing procedures. Except for the development of a liquid limit device and subsequent minor refinements the method has remained basically unchanged for over a half century. The empirical determination of an arbitrary limit would seem to be contrary to the very foundations of scientific procedures. However, the tests are relatively simple and the results are generally acceptable and valuable in almost every conceivable use of soil from an engineering standpoint. Such a great volume of information has been collected and compiled by application of these limits to cohesive soils, that it would be impractical and virtually impossible to replace the tests with a more rational testing method. Nevertheless, many believe that the present method is too time consuming and inconsistent. Research was initiated to investigate the development of a rapid and consistent method by relating the limits to soil moisture tension values determined by porous plate and pressure membrane apparatus. With the moisture tension method, hundreds of samples may be run at one time, operator variability is minimal, results are consistent, and a high degree of correlation to present liquid limit tests is possible.

Concrete Pavement Mixture Design and Analysis (MDA): Development and Evaluation of Vibrating Kelly Ball Test (VKelly Test) for the Workability of Concrete, 2015

Due to the low workability of slipform concrete mixtures, the science of rheology is not strictly applicable for such concrete. However, the concept of rheological behavior may still be considered useful. A novel workability test method (Vibrating Kelly Ball or VKelly test) that would quantitatively assess the responsiveness of a dry concrete mixture to vibration, as is desired of a mixture suitable for slipform paving, was developed and evaluated. The objectives of this test method are for it to be cost-effective, portable, and repeatable while reporting the suitability of a mixture for use in slipform paving. The work to evaluate and refine the test was conducted in three phases: 1. Assess whether the VKelly test can signal variations in laboratory mixtures with a range of materials and proportions 2. Run the VKelly test in the field at a number of construction sites 3. Validate the VKelly test results using the Box Test developed at Oklahoma State University for slipform paving concrete The data collected to date indicate that the VKelly test appears to be suitable for assessing a mixture’s response to vibration (workability) with a low multiple operator variability. A unique parameter, VKelly Index, is introduced and defined that seems to indicate that a mixture is suitable for slipform paving when it falls in the range of 0.8 to 1.2 in./√s.