Determination of the Optimum Base Characteristics for Pavements, TR-482, 2004

In recent years, it has become apparent that the design and maintenance of pavement drainage extends the service life of pavements. Most pavement structures now incorporate subsurface layers. Part of the function of these subsurface layers is to drain away excess water, which can be extremely deleterious to the life of the pavement. To assure the effectiveness of such drainage layers after they have been spread and compacted, simple, rapid, in-situ permeability and stability testing and end-result specification are needed. This report includes conclusions and recommendations related to four main study objectives: (1) Determine the optimal range for in-place stability and in-place permeability based on Iowa aggregate sources; (2) Evaluate the feasibility of an air permeameter for determining the permeability of open and well-graded drainage layers in situ; (3) Develop reliable end-result quality control/quality assurance specifications for stability and permeability; and (4) Refine aggregate placement and construction methods to optimize uniformity.

Image Analysis of PCC and AC Pavements Using SEM Images, HR-346, 1994

The major objective of this work was to evaluate the potential of image analysis for characterizing air voids in Portland cement Concrete (PCC), voids and constituents of Asphalt Concrete (AC) and aggregate gradation in AC. Images for analysis were obtained from a scanning electron microscope (SEM). Sample preparation techniques are presented that enhance signal differences so that backscattered electron (BSE) imaging, which is sensitive to atomic number changes, can be effectively employed. Work with PCC and AC pavement core samples has shown that the low vacuum scanning electron microscope (LVSEM) is better suited towards rapid analyses. The conventional high vacuum SEM can also be used for AC and PCC analyses but some distortion within the sample matrix will occur. Images with improved resolution can be obtained from scanning electron microscope (SEM) backscatter electron (BSE) micrographs. In a BSE image, voids filled with barium sulfate/resin yield excellent contrast in both PCC and AC. There is a good correlation between percent of air by image analysis and linear traverse.

Image Analysis for the Characterization of Materials for Highway Construction : Phase I, Progress Report, HR-346, 1992

The major objective of this project is to evaluate image analysis for characterizing air voids in Portland cement contract (PCC) and asphalt concrete (AC) and aggregate gradation in asphalt concrete. Phase 1 of this project has concentrated on evaluation and refinement of sample preparation techniques, evaluation of methods and instruments for conducting image analysis, and finally, analysis and comparison of a select portion of samples. Preliminary results suggest a strong correlation between the results obtained from the linear traverse method and image analysis methods for determining percent air voids in concrete. Preliminary work with asphalt samples has shown that damage caused by a high vacuum of the conventional scanning electron microscope (SEM) may too disruptive. Alternative solutions have been explored, including confocal microscopy and low vacuum electron microscopy. Additionally, a conventional high vacuum SEM operating at a marginal operating vacuum may suffice.

IoWoman, September/October 2002, Vol. 32, no. 5

Newsletter for Commission on the Status of Women.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, January 16, 2013; With Addendums

Weekly letting report.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, May 21, 2013; With Addendums

Weekly letting report.

Pieces of Iowa’s Past, January 25, 2012

Pieces of Iowa’s Past, published by the Iowa State Capitol Tour Guides weekly during the legislative session, features historical facts about Iowa, the Capitol, and the early workings of state government. All historical publications are reproduced here with the actual spelling, punctuation, and grammar retained. January 25, 2012 THIS WEEK: HOUSE RESOLUTIONS PRESENTED ON JANUARY 8, 1866 BACKGROUND: Background: The 11th General Assembly convened January 8, 1866, and adjourned April 3, 1866—an 86-day session. There were 146 members in the legislature, 48 senators and 98 representatives. Iowa’s Governor was William Milo Stone, and the 1860 census showed Iowa’s population at 482,699. Robert Finkbine represented House district 26. It was Finkbine’ s second term. He was 37 and listed his occupation as “builder.” Robert Finkbine went on to become the Superintendent of Construction for the present day Capitol. House district 26 represented Johnson County in 1866. In 1878, Marion County became the constituency for House district 26. The representative in House district 26 in 1878 was William Milo Stone, previous governor and resident of Knoxville

Iowa Department of Transportation Major Items - Preliminary Quantity Report, February 17, 2015; With Addendums

Weekly letting report.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, January 20, 2016; With Addendums

Weekly letting report