Friday Facts, May 16, 2014, Vol. 212

Bureau of Nutrition and Health Promotion part of the Iowa Department of Public Health produces of weekly newsletter about the Iowa WIC Program for the State of Iowa citizen.

Treating Iowa's Marginal Aggregates and Soils by Foamix Process, HR-212, 1980

Quality granular materials suitable for building all-weather roads are not uniformly distributed throughout the state of Iowa. For this reason the Iowa Highway Research Board has sponsored a number of research programs for the purpose of developing new and effective methods for making use of whatever materials are locally available. This need is ever more pressing today due to the decreasing availability of road funds and quality materials, and the increasing costs of energy and all types of binder materials. In the 1950s, Professor L. H. Csanyi of Iowa State University had demonstrated both in the laboratory and in the field, in Iowa and in a number of foreign countries, the effectiveness of preparing low cost mixes by stabilizing ungraded local aggregates such as gravel, sand and loess with asphalt cements using the foamed asphalt process. In this process controlled foam was produced by introducing saturated steam at about 40 psi into heated asphalt cement at about 25 psi through a specially designed and properly adjusted nozzle. The reduced viscosity and the increased volume and surface energy in the foamed asphalt allowed intimate coating and mixing of cold, wet aggregates or soils. Through the use of asphalt cements in a foamed state, materials normally considered unsuitable could be used in the preparation of mixes for stabilized bases and surfaces for low traffic road construction. By attaching the desired number of foam nozzles, the foamed asphalt can be used in conjunction with any type of mixing plant, either stationary or mobile, batch or continuous, central plant or in-place soil stabilization.

Footnotes May/June 2000, Vol.24, No.5/6

Monthly newsletter of the State Library of Iowa

Iowa's Adult Basic Education Program Annual Benchmark Report, 2002

One of the major intents of AEFLA was to establish performance measures and benchmarks to demonstrate increased accountability in line with the major goals and objectives of WIA. Section 212(2)(A) of the Act specifies that each eligible agency (e.g. The Iowa Department of Education) is subject to certain core indicators of performance and has the authority to specify additional indicators.

Iowa Adult Literacy Local Program Monitoring Guidelines Revised, July 2007

The purpose of this document is to provide guidelines for the annual monitoring and evaluation of Iowa’s adult literacy funded local programs. Section 224(b)(3) of the Adult Education and Family Literacy Act (AEFLA) states that the State Education Agency (SEA) will provide “a description of how the eligible agency [Iowa Department of Education] will evaluate annually the effectiveness of the adult education and literacy activities based on the performance measures described in section 212.” In compliance with that mandate, the following describes the Iowa Department of Education’s procedures for local adult literacy program evaluation strategies.

Iowa Leading Indicators Index January 2009

The Iowa Leading Indicators Index (ILII) is a tool for monitoring the future direction of the Iowa economy and State revenues. Its eight components include an agricultural futures price index, an Iowa stock market index, average weekly manufacturing hours in Iowa, initial unemployment claims in Iowa, an Iowa new orders index, diesel fuel consumption in Iowa, residential building permits in Iowa, and the national yield spread.

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, February 19, 2013; With Addendums

Weekly letting report.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, December 17, 2013; With Addendums

Weekly letting report.

Field Demonstration and Laboratory Evaluation of Foamed Asphalts - Muscatine County, HR-233, 1985

In view of the energy, environmental, and economic advantages of the foamed asphalt process using local aggregates in cold mixes and the promising results from Research Project HR-212, a 4.2-mile section of county road in Muscatine County was built with foamed asphalt and local aggregates during August-September 1983. Extensive laboratory evaluation was carried out on five plant mixes representing foamed mixes used in the nine test sections, a laboratory prepared foamed mix, and a laboratory prepared hot mix similar to Plant Mix 1. The foamed mixes were compacted, cured under 15 curing conditions and tested for bulk specific gravity, Marshall stability at 77° F and at 140° F, cured moisture content, resilient modulus and effects of moisture damage due to freeze-thaw cycles, water soaking, and vacuum saturation. In addition, four sets of 83 core samples were taken at 1 to 15 months and tested for moisture content, specific gravity, Marshall stability, and resilient modulus. In summary, the test road has performed satisfactorily for almost two years. The few early construction problems encountered were to be expected for experimental projects dealing with new materials and technologies. Overall results to date are encouraging and foamed asphalt mixes have proved to have the potential as a viable base material in areas where marginal aggregates are available. It is hoped and expected that performance evaluation of the test sections will be continued and that more foamed asphalt trial projects will be constructed and monitored so that experiences and findings from this project can be verified and mix design criteria can be gradually established. For future foamed asphalt projects it is recommended that anti-stripping additives, such as hydrated lime, be added in view of the potential moisture susceptibility of foamed mixes observed in the laboratory evaluation.

Thin Bonded Overlay Evaluation, Construction Report, HR-559, 1999

In recent years, ultra-thin whitetopping (UTW) has evolved as a viable rehabilitation technique for deteriorated asphalt cement concrete (ACC) pavement. Numerous UTW projects have been constructed and tested, enabling researchers to identify key elements contributing to their successful performance. These elements include foundation support, the interface bonding condition, portland cement concrete (PCC) overlay thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. The interface bonding condition is the most important of these elements. It enables the pavement to act as a composite structure, thus reducing tensile stresses and allowing an ultra-thin PCC overlay to perform as intended. Although the main factors affecting UTW performance have been identified in previous research, neither the impact that external variables have on the elements nor the element interaction have been thoroughly investigated. The objective of this research was to investigate the interface bonding condition between an ultra-thin PCC overlay and an ACC base over time, considering the previously mentioned variables. Laboratory testing and full scale field testing were planned to accomplish the research objective. Laboratory testing involved monitoring interface strains in fabricated PCC/ACC composite test beams subjected to either static or dynamic flexural loading. Variables investigated included ACC surface preparation, PCC thickness, and synthetic fiber reinforcement usage. Field testing involved monitoring PCC/ACC interface stains and temperatures, falling weight deflectometer (FWD) deflection responses, direct shear strengths, and distresses on a 7.2 mile Iowa Department of Transportation (Iowa DOT) UTW project (HR-559). The project was located on Iowa Highway 21 between Iowa Highway 212 and U.S. Highway 6 in Iowa County, near Belle Plaine, Iowa. Variables investigated included ACC surface preparation, PCC thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. This report documents the planning, equipment selection, and construction of the project built in 1994.

Iowa Ultra Thin Whitetopping at Two Years of Age, HR-559, 1996

An 11.6 km research project was constructed in 1994 on a portion of Iowa Highway 21 in Iowa County, from U.S. 6 to Iowa Highway 212. This research is intended to evaluate the effect of four primary variables on long term performances of the PCC concrete overlay, commonly called whitetopping. The variables are thickness (50 mm, 100 mm, 150 mm, and 200 mm), joint spacing (0.6 m squares, 1.2 m squares, 1.8 m squares, and 4.6 m spacing), fiber use (concrete with and without polypropolene fibers) and surface preparation (patch only, scarifying the surface, and cold-in-place recycling). After two years, only two sections exhibit a small amount of debonding and distress cracking. Both sections are 50 mm thick. Within each of these two sections, only 2% of the area is affected. Two other 50 mm thick sections have a small number of cracks but no debonding has been found. No adverse effects of these cracks are evident. Three asphalt overlay sections were also constructed. In each asphalt section, transverse cracks have recently been found. At two years of age, the research sections are performing very well. An insignificant number of cracks and no distressed areas have been found in any research sections thicker than 50 mm.

Ultrathin Portland Cement Concrete Overlay Extended Evaluation, Construction Report, TR-432, 2000

In recent years, ultra-thin whitetopping (UTW) has evolved as a viable rehabilitation technique for deteriorated asphalt cement concrete (ACC) pavement. Numerous UTW projects have been constructed and tested, enabling researchers to identify key elements contributing to their successful performance. These elements include foundation support, interface bonding condition, portland cement concrete (PCC) overlay thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. The interface bonding condition is the most important of these elements. It enables the pavement to act as a composite structure, thus reducing tensile stresses and allowing an ultra-thin PCC overlay to perform as intended. The Iowa Department of Transportation (Iowa DOT) UTW project (HR-559) initiated UTW in Iowa. The project is located on Iowa Highway 21 between Iowa Highway 212 and U.S. Highway 6 in Iowa County, near Belle Plaine, Iowa. The objective of this research was to investigate the interface bonding condition between an ultra-thin PCC overlay and an ACC base over time, considering the previously mentioned variables. This research lasted for five years, at which time it was extended an additional five years. The new phase of the project was initiated by removing cracked panels existing in the 2-inch thick PCC sections and replacing them with three inches of PCC. The project extension (TR 432) will provide an increased understanding of slab bonding conditions over a longer period, as well as knowledge regarding the behavior of the newly rehabilitated areas. In order to accomplish the goals of the project extension, Falling Weight Deflectometer (FWD) testing will continue to be conducted. Laboratory testing, field strain gage implementation, and coring will no longer be conducted. This report documents the planning and construction of the rehabilitation of HR 559 and the beginning of TR 432 during August of 1999.

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

Weekly letting report.

Ultrathin Portland Cement Concrete Overlay Extended Evaluation, Interim Report, TR-432, 2002

The Iowa Department of Transportation (Iowa DOT) UTW Project (HR-559) initiated Ultra-Thin Whitetopping in Iowa. The project is located on Iowa Highway 21 between Iowa Highway 212 and U.S. Highway 6 in Iowa County, near Belle Plaine, Iowa. The above listed research project lasted for five years, and then was extended for another five year period. The new phase of the project (TR 432) was initiated by removing cracked panels existing in the 2-inch thick PCC sections and replacing them with three inches of PCC. The project extension provides an increased understanding of slab bonding conditions over a longer period, as well as knowledge regarding the behavior of the newly rehabilitated areas. This report documents the rehabilitation of the PCC patching of all fractured panels and several cracked panels, taking place in September of 2001.