U.S. Highway 20 Corridor Development Study - Report C: Final Screening of Alternative Candidate Improvements, 1992

This report briefly compares the alternative improvement options using analyses conducted to date, and is intended to identify the alternatives which should be carried forward into the study's economic evaluation phase.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2012 - 2013 School Year, August 20, 2013

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2011 - 2012 School Year, November 20, 2012

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2013-2014 School Year, August 15, 2014

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health Oral Health Bureau School Dental Screening Audit Report - State Summary 2008-2009 School Year, December 1, 2009

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health Oral Health Bureau School Dental Screening Audit Report - State Summary 2009-2010 School Year, December 1, 2010

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2010 - 2011 School Year, September 14, 2011

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2014-2015 School Year, August 11, 2015

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2013-2014 School Year, August 15, 2014

School dental screening of all high schools in Iowa that have participated. A state summary.

Iowa Department of Public Health School Dental Screening Requirement - State Compliance 2014-2015 School Year, September 11, 2015

School dental screening of all high schools in Iowa that have participated. A state summary.

Surface Improvement and Dust Palliation of Unpaved Secondary Roads and Streets, Progress Report, HR-151, 1971

A combined study of dust control and low-cost surface improvements of soil and aggregate materials for immediate (and intermediate) use as a treated surface course is being conducted in three concurrent phases: (1) laboratory screening of various additives thought to have potential for long-lasting dust palliation, soil-additive strength, durability, and additive retention potential; (2) test road construction, using those additives from the screening studies that indicate promise for performance and serviceability; and (3) observation and tests of constructed sections for evaluation of the additive's contribution to performance and serviceability as well as relationship to initial costs. A brief review is presented of the problem, some methods of measuring it, previously adopted approaches to it, project field tests and a portion of the results thus far, and portions of the laboratory work accomplished in the screening studies.

Development of Self-Cleaning Box Culvert Designs, TR-545, 2009

The main function of a roadway culvert is to effectively convey drainage flow during normal and extreme hydrologic conditions. This function is often impaired due to the sedimentation blockage of the culvert. This research sought to understand the mechanics of sedimentation process at multi-box culverts, and develop self-cleaning systems that flush out sediment deposits using the power of drainage flows. The research entailed field observations, laboratory experiments, and numerical simulations. The specific role of each of these investigative tools is summarized below: a) The field observations were aimed at understanding typical sedimentation patterns and their dependence on culvert geometry and hydrodynamic conditions during normal and extreme hydrologic events. b) The laboratory experiments were used for modeling sedimentation process observed insitu and for testing alternative self-cleaning concepts applied to culverts. The major tasks for the initial laboratory model study were to accurately replicate the culvert performance curves and the dynamics of sedimentation process, and to provide benchmark data for numerical simulation validation. c) The numerical simulations enhanced the understanding of the sedimentation processes and aided in testing flow cases complementary to those conducted in the model reducing the number of (more expensive) tests to be conducted in the laboratory. Using the findings acquired from the laboratory and simulation works, self-cleaning culvert concepts were developed and tested for a range of flow conditions. The screening of the alternative concepts was made through experimental studies in a 1:20 scale model guided by numerical simulations. To ensure the designs are effective, performance studies were finally conducted in a 1:20 hydraulic model using the most promising design alternatives to make sure that the proposed systems operate satisfactory under closer to natural scale conditions.

Standards for Single Span Prefabricated Bridges, Phase I - Concept Development, TR-663, 2014

In coordination with a Technical Advisory Committee (TAC) consisting of County Engineers and Iowa DOT representatives, the Iowa DOT has proposed to develop a set of standards for a single span prefabricated bridge system for use on the local road system. The purpose of the bridge system is to improve bridge construction, accelerate project delivery, improve worker safety, be cost effective, reduce impacts to the travelling public by reducing traffic disruptions and the duration of detours, and allow local forces to construct the bridges. HDR Inc. was selected by the Iowa DOT to perform the initial concept screening of the bridge system. This Final Report summarizes the initial conceptual effort to investigate potential systems, make recommendations for a preferred system and propose initial details to be tested in the laboratory in Phase 2 of the project. The prefabricated bridge components were to be based on the following preliminary criteria set forth by the TAC. The criteria were to be verified and/ or modified as part of the conceptual development. - 24’ and 30’ roadway widths - Skews of 0o, 15o, and 30o - Span lengths of 30’ – 70’ in 10’ increments using precast concrete beams - Voided box beams could be considered - Limit precast element weight to 45,000 pounds for movement and placement of beams - Beams could be joined transversely with threaded rods - Abutment concepts may included precast as well as an option for cast-in-place abutments with pile foundations In addition to the above criteria, there was an interest to use a single-width prefabricated bridge component to simplify fabrication as well as a desire to utilize non-prestressed concrete systems where possible to allow for precasting of the beam modules by local forces or local precast plants. The SL-1 modular steel bridge rail was identified for use with this single span prefabricated bridge system.