Student Strong, Iowa Proud, Board of Regents Annual Report, 2014

This report is the annual report for the Board of Regents.

Investigation of Rapid Thermal Analysis Procedures for Prediction of the Service Life of PCCP Carbonate Coarse Aggregate, HR-337, 1993

The major objective of this research project was to use thermal analysis techniques in conjunction with x-ray analysis methods to identify and explain chemical reactions that promote aggregate related deterioration in portland cement concrete. Twenty-two different carbonate aggregate samples were subjected to a chemical testing scheme that included: • bulk chemistry (major, minor and selected trace elements) • bulk mineralogy (minor phases concentrated by acid extraction) • solid-solution in the major carbonate phases • crystallite size determinations for the major carbonate phases • a salt treatment study to evaluate the impact of deicer salts Test results from these different studies were then compared to information that had been obtained using thermogravimetric analysis techniques. Since many of the limestones and dolomites that were used in the study had extensive field service records it was possible to correlate many of the variables with service life. The results of this study have indicated that thermogravimetric analysis can play an important role in categorizing carbonate aggregates. In fact, with modern automated thermal analysis systems it should be possible to utilize such methods on a quality control basis. Strong correlations were found between several of the variables that were monitored in this study. In fact, several of the variables exhibited significant correlations to concrete service life. When the full data set was utilized (n = 18), the significant correlations to service life can be summarized as follows ( a = 5% level): • Correlation coefficient, r, = -0.73 for premature TG loss versus service life. • Correlation coefficient, r, = 0.74 for relative crystallite size versus service life. • Correlation coefficient, r, = 0.53 for ASTM C666 durability factor versus service life. • Correlation coefficient, r, = -0.52 for acid-insoluble residue versus service life. Separation of the carbonate aggregates into their mineralogical categories (i.e., calcites and dolomites) tended to increase the correlation coefficients for some specific variables (r sometimes approached 0.90); however, the reliability of such correlations was questionable because of the small number of samples that were present in this study.

07003-001 Clear Lake Watershed Final Report

Clear Lake, Iowa's third largest natural lake, is a premier natural resource and popular recreational destination in north central Iowa. Despite the lake's already strong recreational use, water quality concerns have not allowed the lake to reach its full potential. Clear Lake is listed on Iowa's 2004 303(d) Impaired Waters List due to excessive levels of phosphorus, bacteria, and turbidity. Urban storm water runoff from the 8,600 acre watershed is a significant contributor to Clear Lake's impairment. Local communities have been working towards the goal of making improvements at all 30 storm water outlets that have a drainage area of five acres or more and have a cost effective solution. Many improvements have already been made, and now there are only seven storm water outlet sites remaining that still need protection in order to meet the goal. The storm water improvements have been very effective in reducing contaminants in urban runoff, achieving reduction levels in the 50-80% range. The proposed Clear Lake Storm Water Improvement Project will address the remaining seven outlet sites and take place over three years. The first year will consist of performing engineering and design of storm water best management practices (BMPs) at the seven outlet sites to determine if a cost effective solution exists for each. Years two and three will consist of installing two storm water improvements each year to implement the most cost effective BMPs at a minimum of four of the seven sites. The grant request addresses one of the main priorities of the Iowa Watershed Improvement Grant: storm water runoff.

Do fire and seed additions alter strong seed timing and priority effects on prairie establishment?, 2011

Many prairie restoration projects are hampered by a lack of knowledge on how to restore the high diversity found in prairies, while at the same time preventing the establishment of a large weedy component. Methods are needed to increase diversity and abundance of native species while minimizing exotic species invasions in both 1) newly planted restorations and 2) established restorations. We established an experiment in Story and Monona counties in 2005 to determine the effects of different native cover crop species and timing of seeding on the establishment of new prairie restorations. We found that adding a 30-species prairie mix in early spring led to diverse native communities, but adding the mix in the late summer or the following year after cover crops established led to low diversity communities dominated by exotics. The identity of cover crops affected communities less than timing of seed additions. A second seed addition added to ash after a spring fire in the seventh year (Monona County site) increased recruitment from the prairie mix slightly, but the increase was not enough to cause convergence in the treatments. Surprisingly, the second seed addition increased diversity only in communities that were already the most diverse (i.e., in plots seeded with the prairie mix in early spring before cover crops established). These results imply that 1) cover crops are not effective for establishing prairie and 2) over seeding into established plots may not be an easy and efficient way to increase native recruitment and lower weedy species abundances. Therefore, focusing on establishing high levels of recruitment and diversity and excluding weedy species during the critical time early in establishment should be a priority for new projects.