Crack Development in Ternary Mix Concrete Utilizing Various Saw Depths, TR-587, 2009

Early entry sawing applies sawing earlier and more shallowly than conventional sawing and is believed to increase sawing productivity and reduce the cost of the joint sawing operations. However, some early entry sawing joints (transverse joints) in Iowa were found to experience delayed cracking, sometimes up to 30 days. A concern is whether early entry sawing can lead to late-age random cracking. The present study investigated the effects of different sawing methods on random cracking in portland cement concrete (PCC) pavements. The approach was to assess the cracking potential at sawing joints by measuring the strain development of the concrete at the joints using concrete embedment strain gages. Ten joints were made with the early entry sawing method to a depth of 1.5 in., and two strain gages were installed in each of the joints. Another ten joints were made with the conventional sawing method, five of which were sawed to a depth of one-third of the pavement thickness (3.3 in.), and the other five of which were sawed to a depth of one-quarter of the pavement thickness (2.5 in.). One strain gage was installed in each joint made using conventional sawing. In total, 30 strain gages were installed in 20 joints. The results from the present study indicate that all 30 joints cracked within 25 days after paving, though most joints made using early entry sawing cracked later than the joints made using conventional sawing. No random cracking was observed in the early entry sawing test sections two months after construction. Additionally, it was found that the strain gages used were capable of monitoring the deformations at the joints. The joint crack times (or crack initiation time) measured by the strain gages were generally consistent with the visual observations.

Manual of Laboratory Mix Design Procedure for Cold In-Place Recycling using Foamed Asphalt (CIR-foam), TR-474, 2007

The objective is to determine the optimum percentage of water needed to produce the best foam properties for a given asphalt binder. The optimum water content is determined by achieving the maximum expansion ratio and half-life of the foamed asphalt. Expansion ratio is defined as the maximum volume over its original volume and half-life is defined as the time in seconds for foam to become a half of its maximum volume.

Superpave Mix Designs for Low-Volume Roads, TR-414, Final Report, 2004

Most research current to the time of these projects was focused on use of Superpave mix designs on higher volume roads. Low volume roads have different requirements in terms of mix design, aggregate types, aggregate sources and project budgets. The purpose of this research was to determine if the Superpave mix design strategy for low volume roads was practical and economical. Eight projects were selected in five counties. The projects were completed in the summer of 1998. Performance evaluation of the resulting pavements was carried out annually. There was no significant increase in costs related to the use of Superpave. Nor were there any significant construction issues. There were some differences noted in placement and compaction in the field, but these were not serious.

Report on the Iowa Braille and Sight Saving School, Vinton, Iowa for the year ended June 30, 2014

Report on the Iowa Braille and Sight Saving School, Vinton, Iowa for the year ended June 30, 2014

Report on the Iowa School for the Deaf, Council Bluffs, Iowa for the year ended June 30, 2014

Report on the Iowa School for the Deaf, Council Bluffs, Iowa for the year ended June 30, 2014

Reaudit report on the North Cedar Community School District for the period July 1, 2012 through June 30, 2013

Reaudit report on the North Cedar Community School District for the period July 1, 2012 through June 30, 2013

Iowa School Library Program Guidelines: Libraries, Literacy and Learning for the 21st Century,February 2007

These guidelines were created by a Task Force appointed by the State Library of Iowa and the Iowa Department of Education to provide assistance to local school districts in developing school library programs. These include a summary of the data collected annually by the State Library of Iowa in its Survey of School Libraries. This data will allow local schools to compare themselves in terms of collections, budgets and staffing to schools of similar size throughout the state.

Mix Design Development for Pervious Concrete in Cold Weather Climates

Portland cement pervious concrete (PCPC) is being used more frequently due to its benefits in reducing the quantity of runoff water,improving water quality, enhancing pavement skid resistance during storm events by rapid drainage of water, and reducing pavement noise. In the United States, PCPC typically has high porosity and low strength, which has resulted in the limited use of pervious concrete, especially in hard wet freeze environments (e.g., the Midwestern and Northeastern United States and other parts of the world).Improving the strength and freeze-thaw durability of pervious concrete will allow an increase in its use in these regions. The objective of this research is to develop a PCPC mix that not only has sufficient porosity for stormwater infiltration, but also desirable strength and freeze-thaw durability. In this research, concrete mixes were designed with various sizes and types of aggregates, binder contents, and admixture amounts. The engineering properties of the aggregates were evaluated. Additionally, the porosity, permeability, strength, and freeze-thaw durability of each of these mixes was measured. Results indicate that PCPC made with single-sized aggregate has high permeability but not adequate strength. Adding a small percent of sand to the mix improves its strength and freeze-thaw resistance, but lowers its permeability. Although adding sand and latex improved the strength of the mix when compared with single-sized mixes, the strength of mixes where only sand was added were higher. The freeze-thaw resistance of PCPC mixes with a small percentage of sand also showed 2% mass loss after 300 cycles of freeze-thaw. The preliminary results of the effects of compaction energy on PCPC properties show that compaction energy significantly affects the freeze-thaw durability of PCPC and, to a lesser extent, reduces compressive strength and split strength and increases permeability.

School Leader Update, August 2015

Monthly newsletter produced by Iowa Department of Education

Report on a special investigation of the Nutrition Department of the Northeast Hamilton Community School District for the period August 1, 2013 through June 4, 2014

Report on a special investigation of the Nutrition Department of the Northeast Hamilton Community School District for the period August 1, 2013 through June 4, 2014

School Leader Update, October 2015

Monthly newsletter produced by Iowa Department of Education

Iowa Community Colleges High School Enrollment Report, February 2006

Community Colleges of Iowa transmit fiscal year enrollment data to the Department of Education. All data included in this report, except where noted, are taken from the Management Information System (MIS) electronic data files and are confirmed by the community college.

Third Annual Iowa Community Colleges High School Enrollment Report, January 2007

Community Colleges of Iowa transmit fiscal year enrollment data to the Department of Education. All data included in this report, except where noted, are taken from the Management Information System (MIS) electronic data files and are confirmed by the community college.

Iowa Community Colleges High School Enrollment Report, July 2008

Community Colleges of Iowa transmit fiscal year enrollment data to the Department of Education. All data included in this report, except where noted, are taken from the Management Information System (MIS) electronic data files and are confirmed by the community college.

Second Annual Iowa Community Colleges High School Enrollment Report, February 2006

Community Colleges of Iowa transmit fiscal year enrollment data to the Department of Education. All data included in this report, except where noted, are taken from the Management Information System (MIS) electronic data files and are confirmed by the community college.