Student Health Facility Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report, Financial Statements and Supplemental Information, June 30, 2005

State University Audit Report

Portland Cement Concrete Patching Techniques vs. Performance and Traffic Delay, January 2004

Standards for the construction of full-depth patching in portland cement concrete pavement usually require replacement of all deteriorated based materials with crushed stone, up to the bottom of the existing pavement layer. In an effort to reduce the time of patch construction and costs, the Iowa Department of Transportation and the Department of Civil, Construction and Environmental Engineering at Iowa State University studied the use of extra concrete depth as an option for base construction. This report compares the impact of additional concrete patching material depth on rate of strength gain, potential for early opening to traffic, patching costs, and long-term patch performance. This report also compares those characteristics in terms of early setting and standard concrete mixes. The results have the potential to change the method of Portland cement concrete pavement patch construction in Iowa.

Sustainable Development and Concrete Technology, May 2004

For a variety of reasons, the concrete construction industry is not sustainable. First, it consumes huge quantities of virgin materials. Second, the principal binder in concrete is portland cement, the production of which is a major contributor to greenhouse gas emissions that are implicated in global warming and climate change. Third, many concrete structures suffer from lack of durability which has an adverse effect on the resource productivity of the industry. Because the high-volume fly ash concrete system addresses all three sustainability issues, its adoption will enable the concrete construction industry to become more sustainable. In this paper, a brief review is presented of the theory and construction practice with concrete mixtures containing more than 50% fly ash by mass of the cementitious material. Mechanisms are discussed by which the incorporation of high volume of fly ash in concrete reduces the water demand, improves the workability, minimizes cracking due to thermal and drying shrinkage, and enhances durability to reinforcement corrosion, sulfate attack, and alkali-silica expansion. For countries like China and India, this technology can play an important role in meeting the huge demand for infrastructure in a sustainable manner.

Two-Lift Portland Cement Concrete Pavements to Meet Public Needs, September 2004

The report reviews the past work in the United States and internationally in the development of two-lift pavements. It points out the strengths and limitations in the construction of such portland cement concrete pavements. Certain cost, mix design, and construction problems are inhibiting the growth of this product. Changes in the availability of aggregates, knowledge of materials and new construction equipment, and the desire for specific surfaces to meet noise, durability, and safety are prompting the need to reconsider this type of construction.

Blended Cements Improving Concrete Properties Using Environmentally Responsible Mixtures, December 2003

Recent research evaluated the behavior of concrete made with supplementary cementitious materials (SCMs) such as fly ash and ground granulated blast-furnace slag under a variety of conditions. Correlations were found among the source and proportion of the SCMs, curing conditions, concrete set time, maturity, strength development, and cracking potential.

Concrete Paving Notes Construction No.1, 2005

This booklet will help developers, consultants, and engineers planning concrete pavement construction projects, superintendents and supervisors who want a basic training aid and reference, and crew members new to the concrete paving industry. It provides a general description of current concrete pavement construction practices, from establishing preconstruction control mechanisms to sealing joints. It also provides a quick troubleshooting reference.

Long-term Plan for Concrete Pavement Research and Technology: The CP Road Map, November 2004, Volume 1 of 2

An Iowa State University–led team facilitated development of the CP Road Map. They developed a database of existing research. They gathered input, face to face, from the highway community. They identified gaps in research that became the basis for problem statements, which they organized into a cohesive, strategic research plan.

Long-term Plan for Concrete Pavement Research and Technology: The CP Road Map, November 2004, Volume 2 of 2

An Iowa State University–led team facilitated development of the CP Road Map. They developed a database of existing research. They gathered input, face to face, from the highway community. They identified gaps in research that became the basis for problem statements, which they organized into a cohesive, strategic research plan.

Long-term Plan for Concrete Pavement Research and Technology: The CP Road Map, November 2004

An Iowa State University–led team facilitated development of the CP Road Map. They developed a database of existing research. They gathered input, face to face, from the highway community. They identified gaps in research that became the basis for problem statements, which they organized into a cohesive, strategic research plan.

Dowel Bar Optimization: Phases I and II, October 2001

America’s roadways are in serious need of repair. According to the American Society of Civil Engineers (ASCE), one-third of the nation’s roads are in poor or mediocre condition (1). ASCE has estimated that under these circumstances American drivers will sacrifice $5.8 billion and as many as 13,800 fatalities a year from 1999 to 2001 ( 1). A large factor in the deterioration of these roads is a result of how well the steel reinforcement transfers loads across the concrete slabs. Fabricating this reinforcement using a shape conducive to transferring these loads will help to aid in minimizing roadway damage. Load transfer within a series of concrete slabs takes place across the joints. For a typical concrete paved road, these joints are approximately 1/8-inch gaps between two adjacent slabs. Dowel bars are located at these joints and used to transfer load from one slab to its adjacent slabs. As long as the dowel bar is completely surrounded by concrete no problems will occur. However, when the hole starts to oblong a void space is created and difficulties can arise. This void space is formed due to a stress concentration where the dowel contacts the concrete. Over time, the repeated process of traffic traveling over the joint crushes the concrete surrounding the dowel bar and causes a void in the concrete. This void inhibits the dowel’s ability to effectively transfer load across the joint. Furthermore, this void gives water and other particles a place to collect that will eventually corrode and potentially bind or lock the joint so that no thermal expansion is allowed. Once there is no longer load transferred across the joint, the load is transferred to the foundation and differential settlement of the adjacent slabs will occur.

Improving Concrete Pavement Curing, March 2003

· Evaluate the effect of different curing materials and techniques on concrete pavement properties. · Better understand the relationships between various concrete test measurements and concrete properties affected by curing.

Moblie Concrete Research Lab, 2004

A new, state-of-the-art mobile lab has recently been launched from the PCC Center at Iowa State University to bring high-tech concrete materials and concrete pavement testing capabilities to the field. The Mobile Concrete Research Lab has been custom built and fully outfitted with equipment capable of performing a comprehensive suite of tests.

Developing Smooth, Quiet, Safe Portland Cement Concrete Pavements, March 2004

The concrete paving industry has spent large amounts of time working to provide safe, quiet, and smooth pavements for the traveling public as their needs and driving habits have changed since the advent of the automobile. During that time, the efforts of research, design, and construction were directed at one of the problems at a time. Current public surveys indicate that the traveling public wishes to have safe, quiet, and smooth pavements. This report identifies the problems remaining in the areas of developing smooth, quiet, and safe portland cement concrete pavement in each pavement we build. It develops the research framework that can be used to bring the existing information together with additional research in each area. The resulting answers can be used in each pavement design for a quiet, safe, and smooth pavement that is also long lasting.

Two Lift Portland Cement Concrete Pavements to Meet Public Needs, September 2004

The report reviews the past work in the United States and internationally in the development of two-lift pavements. It points out the strengths and limitations in the construction of such portland cement concrete pavements. Certain cost, mix design, and construction problems are inhibiting the growth of this product. Changes in the availability of aggregates, knowledge of materials and new construction equipment, and the desire for specific surfaces to meet noise, durability, and safety are prompting the need to reconsider this type of construction.

Evaluation of Composite Pavement Unbonded Overlays: Phases I and II, April 2003

In recent years, thin whitetopping has evolved as a viable rehabilitation technique for deteriorated asphalt cement concrete (ACC) pavements. Numerous projects have been constructed and tested; these projects allow researchers to identify the important elements contributing to the projects’ successes. These elements include surface preparation, overlay thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. Although the main factors affecting thin whitetopping performance have been identified by previous research, questions still existed as to the optimum design incorporating these variables. The objective of this research is to investigate the interaction between these variables over time. Laboratory testing and field-testing were planned in order to accomplish the research objective. Laboratory testing involved shear testing of the bond between the portland cement concrete (PCC) overlay and the ACC surface. Field-testing involved falling weight deflectometer deflection responses, measurement of joint faulting and joint opening, and visual distress surveys on the 9.6-mile project. The project was located on Iowa Highway 13 extending north from the city of Manchester, Iowa, to Iowa Highway 3 in Delaware County. Variables investigated included ACC surface preparation, PCC thickness, synthetic fiber reinforcement usage, and joint spacing. This report documents the planning, equipment selection, construction, field changes, and construction concerns of the project built in 2002. The data from this research could be combined with historical data to develop a design specification for the construction of thin, unbonded overlays.