Friday Facts, May 5, 2014, Vol. 211

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.

Performance of Randomly Oriented, Fiber-Reinforced Roadway Soils, HR-211, 1982

Several primary techniques have been developed through which soil aggregate road material properties may be improved. Such techniques basically involve a mechanism of creating a continuous matrix system of soil and/or aggregate particles, interlocked through the use of some additive such as portland cement, lime, or bituminous products. Details by which soils are stabilized vary greatly, but they are dependent on the type of stabilizing agent and nature of the soil, though the overall approach to stabilization has the common feature that improvement is achieved by some mechanism(s) forcing individual particles to adhere to one another. This process creates a more rigid material, most often capable of resisting the influx of water during freezing, loss of strength due to high moisture content and particle dispersion during thawing, and loss of strength due to migration of fines and/or water by capillarity and pumping. The study reported herein, took a new and relatively different approach to strengthening of soils, i.e., improvement of roadway soils and/or soil-aggregate materials by structural reinforcement with randomly oriented fibers. The purpose of the study was to conduct a laboratory and field investigation into the potential of improving (a) soil-aggregate surfaced and subgrade materials, including those that are frost-prone and/or highly moisture susceptible, and (b) localized base course materials, by uniting such materials through fibrous reinforcement. The envisioned objective of the project was the development of a simple construction technique(s) that could be (a) applied on a selective basis to specific areas having a history of poor performance, or (b) used for improvement of potential base materials prior to surfacing. Little background information on such purpose and objective was available. Though the envisioned process had similarities to fibrous reinforced concrete, and to fibrous reinforced resin composites, the process was devoid of a cementitious binder matrix and thus highly dependent on the cohesive and frictional interlocking processes of a soil and/or aggregate with the fibrous reinforcement; a condition not unlike the introduction of reinforcing bars into a concrete sand/aggregate mixture without benefit of portland cement. Thus the study was also directed to answering some fundamental questions: (1) would the technique work; (2) what type or types of fibers are effective; (3) are workable fibers commercially available; and (4) can such fibers be effectively incorporated with conventional construction equipment, and employed in practical field applications? The approach to obtaining answers to these questions, was guided by the philosophy that an understanding of basic fundamentals was essential to developing a body of engineering knowledge, that would serve as the basis for eventual development of design procedures with fibrous products for the applications previously noted.

Footnotes April 2000, Vol.24, no.4

Monthly newsletter of the State Library of Iowa

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.

List of Bid Proposal Holders, November 19, 2013

List of Bid Proposal Holders

Iowa Department of Transportation Major Items - Preliminary Quantity Report, December 16, 2014; With Addendums

Weekly letting report.

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

Weekly letting report.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, December 15, 2015; With Addendums

Weekly letting report

07020-007 Hurley Creek Watershed/McKinley Lake Final Report

The Hurley Creek Watershed is a micro-watershed of approximately 2,211 acres (3.5 square miles), which drains into the Platte River southwest of Creston. The watershed is 64% urban and 36% rural. The urban area includes the bulk of the town of Creston (population 7,597) and the rural area is just north of Creston, which includes the origin of Hurley Creek. Hurley Creek Watershed was examined for improvements following a citizens group in 2004 determined a need and desire to make McKinley Lake, a 65-acre city-owned lake, a quality fishery and viable swimming lake, as it once was. As part of a major park improvement project over ten-plus years, the watershed improvement project is undertaken to reduce pollution entering the lake. In 2006, IOWATER volunteers, under guidance of the town’s consultants, sampled the stream in 8 locations throughout the year, a total of 92 samples. The samples, along with visual inspections of the creek, found three major impairments: 1) high E. Coli levels, 2) severe erosion, and 3) storm water management. Using the Watershed Project Planning Protocol, the consultant and a volunteer committee of interested citizens determined that five physical and three administrative actions should be undertaken. The request will help: identify sources of E. Coli and reduce its delivery into the watershed, control animal access, manage storm water, implement stream-bank stabilization, educate the public, and develop miscellaneous small projects on specific properties.