Bridge Deck Expansion Assembly on U.S. 20 in Sioux City, HR-505A, 1990

This project was to determine possible construction problems and evaluate the performance of experimental joint seals. Joints were installed in Woodbury County on US 20 over the Missouri River. ACME-Beta B-520 joints were used. Visual inspections were made yearly. Although the joints performed well for eight years, they deteriorated rapidly and have failed. It was concluded these joints did not perform satisfactorily.

Development of an Improved Agricultural-Based Deicing Product, TR-581, 2010

Snow and ice removal on public streets is a critical part of the work of departments of transportation in northern U.S. states, including Iowa. Iowa is also a state rich in agricultural resources, some of which undergo industrial processes that generate a number of byproducts, e.g., in converting corn to ethanol or soy to biodiesel. It would be desirable to find those that, with a minimum of additional processing, can be used as a deicing compound, either alone or in combination with products currently in use. The focus of this work is therefore to investigate by-products from agricultural processes that may be suitable for use as deicing applications. This topic has been investigated in the past by others, with many patented products described in the literature. An initial screening was carried out to assess the potential acceptability of selected commercial products, as well as a glycerol developed for this project. Based on the variety of parameters tested, the product combination that shows the greatest promise for future application consists of 80% glycerol with 20% NaCl.

Time-Temperature Strength-Reaction Product Relationships in Lime-Bentonite-Water Mixtures, HR-111, 1965

The interrelation of curing time, curing temperature, strength, and reactions in lime-bentonite-water mixtures was examined. Samples were molded at constant density and moisture content and then cured for periods of from 1 to 56 days at constant temperatures that ranged from 5C to 60C. After the appropriate curing time the samples were tested for unconfined compressive strength. The broken samples were then analyzed by x-ray diffractometer and spectrophotometer to determine the identity of the reaction products present after each curing period. It was found that the strength gain of lime-clay mixtures cured at different temperatures is due to different phases of the complex reaction, lime & clay to CSH(gel) to CSH(II) to CSH(I) to tobermorite. The farther the reaction proceeds, the higher the strength. There was also evidence of lattice substitutions in the structure of the calcium silicate hydrates at curing temperatures of 50C and higher. No consistent relationship between time, temperature, strength, and the S/A ration of reaction products existed, but in order to achieve high strengths the apparent C/S ration had to be less than two. The curing temperature had an effect on the strength developed by a given amount of reacted silica in the cured lime-clay mixture, but at a given curing temperature the cured sample that had the largest amount of reacted silica gave the highest strength. Evidence was found to indicate that during the clay reaction some calcium is indeed adsorbed onto the clay structure rather than entering into a pozzolanic reaction. Finally, it was determined that it is possible to determine the amount of silica and alumina in lime-clay reaction products by spectrophotometric analysis with sufficient accuracy for comparison purposes. The spectrophotometric analysis techniques used during the investigation were simple and were not time consuming.

Laws of the territory of Iowa passed at the extra session of the legislative assembly : begun and held in the city of Burlington on the first Monday in July in the year of our Lord one thousand eight hundred and forty. 1840

The extra session of the 1840 legislative assembly listing all of the territorial laws of Iowa. The dates of approval of the acts are listed after each one and a brief index is included. This is the 1902 reprint by the Historical Department of Iowa.

Condition of the State of Iowa, 1888 (22nd General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Larrabee delivered at the State Capitol.

Condition of the State of Iowa, 1902 (29nd General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Shaw delivered at the State Capitol.

Condition of the State of Iowa, 1904 (30th General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Cummins delivered at the State Capitol.

Condition of the State of Iowa, 1906 (31st General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Cummins delivered at the State Capitol.

Condition of the State of Iowa, 1923 (40th General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Kendall delivered at the State Capitol.

Condition of the State of Iowa, 1927 (42nd General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Hammill delivered at the State Capitol.

Condition of the State of Iowa, 1929 (43rd General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Hammill delivered at the State Capitol.

Condition of the State of Iowa, 1931 (44th General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Hammill delivered at the State Capitol.

Condition of the State of Iowa, 1933 (45th General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Turner delivered at the State Capitol.

Condition of the State of Iowa, 1935 (46th General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Herring delivered at the State Capitol.

Condition of the State of Iowa, 1937 (47th General Assembly)

A transcript of the Condition of the State of Iowa speech by Governor Herring delivered at the State Capitol.