General highway and transportation map,1978.

Contains a highway map of each county in Iowa

Iowa Department of Transportation Major Items - Preliminary Quantity Report, August 20, 2013; With Addendums

Weekly letting report.

2014-2018 Iowa Transportation Improvement Program

This document describes planned investments in Iowa’s multimodal transportation system including aviation, transit, railroads, trails, and highways. A large part of funding available for highway programming comes from the federal government. Accurately estimating future federal funding levels is dependent on having a multiyear federal transportation authorization bill in place and having a sustainable and solvent federal Highway Trust Fund. The most recent federal authorization, Moving Ahead for Progress in the 21st Century (MAP-21), will expire September 30, 2014. At the same time that MAP-21 expires and absent Congressional action, the federal Highway Trust Fund will no longer be able provide funding at current levels resulting in up to a 90 percent reduction in federal highway funding for federal fiscal year 2015. These two issues provide funding uncertainty with this program in fiscal years 2015 and beyond.

Design Guide for Precast UHPC Waffle Deck Panel System, including Connections, June 2013

Abstract: As a part of an innovation project funded by the Federal Highway Administration (FHWA) Highways for LIFE program, a full-depth precast, ultra-high-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementation of waffle decks were developed. Following a successful full-scale validation test on a unit consisting of two panels with various types of connections under laboratory conditions, the waffle deck was installed successfully on a replacement bridge in Wapello County, Iowa. The subsequent load testing confirmed the desirable performance of the UHPC waffle deck bridge. Using the lessons from the completed project and outcomes from a series of simple and detailed finite element analyses of waffle decks, this report was developed to serve as a guide for broadening the design and installation of the UHPC waffle deck panel in new and existing bridges. Following an introduction to UHPC and waffle deck panels and a summary of completed work, this document presents information on waffle deck design, design of connections, redecking using waffle deck panels, and guidance on precast fabrication, construction, and installation of UHPC waffle deck panels.

Development of a Database for Drilled Shaft Foundation Testing (DSHAFT), June 2012

Drilled shafts have been used in the US for more than 100 years in bridges and buildings as a deep foundation alternative. For many of these applications, the drilled shafts were designed using the Working Stress Design (WSD) approach. Even though WSD has been used successfully in the past, a move toward Load Resistance Factor Design (LRFD) for foundation applications began when the Federal Highway Administration (FHWA) issued a policy memorandum on June 28, 2000.The policy memorandum requires all new bridges initiated after October 1, 2007, to be designed according to the LRFD approach. This ensures compatibility between the superstructure and substructure designs, and provides a means of consistently incorporating sources of uncertainty into each load and resistance component. Regionally-calibrated LRFD resistance factors are permitted by the American Association of State Highway and Transportation Officials (AASHTO) to improve the economy and competitiveness of drilled shafts. To achieve this goal, a database for Drilled SHAft Foundation Testing (DSHAFT) has been developed. DSHAFT is aimed at assimilating high quality drilled shaft test data from Iowa and the surrounding regions, and identifying the need for further tests in suitable soil profiles. This report introduces DSHAFT and demonstrates its features and capabilities, such as an easy-to-use storage and sharing tool for providing access to key information (e.g., soil classification details and cross-hole sonic logging reports). DSHAFT embodies a model for effective, regional LRFD calibration procedures consistent with PIle LOad Test (PILOT) database, which contains driven pile load tests accumulated from the state of Iowa. PILOT is now available for broader use at the project website: http://srg.cce.iastate.edu/lrfd/. DSHAFT, available in electronic form at http://srg.cce.iastate.edu/dshaft/, is currently comprised of 32 separate load tests provided by Illinois, Iowa, Minnesota, Missouri and Nebraska state departments of transportation and/or department of roads. In addition to serving as a manual for DSHAFT and providing a summary of the available data, this report provides a preliminary analysis of the load test data from Iowa, and will open up opportunities for others to share their data through this quality–assured process, thereby providing a platform to improve LRFD approach to drilled shafts, especially in the Midwest region.

Report on the Iowa Department of Transportation for the year ended June 30, 2012

Report on the Iowa Department of Transportation for the year ended June 30, 2012

Modified Sheet Pile Abutments for Low-Volume Road Bridges, January 2012

To date there have been few investigations of the substructures in low-volume road (LVR) bridges. Steel sheet piling has the potential to provide an economical alternative to concrete bridge abutments, but it needs investigation with regard to vertical and lateral load resistance, construction methods, and performance monitoring. The objectives of this project were to develop a design approach for sheet pile bridge abutments for short-span low-volume bridges, formulate an instrumentation and monitoring plan to evaluate performance of sheet pile abutment systems, and understand the cost and construction effort associated with building the sheet pile bridge abutment demonstration project. Three demonstration projects (Boone, Blackhawk, and Tama Counties) were selected for the design, construction, and monitoring of sheet pile abutments bridges. Each site was unique and required site-specific design and instrumentation monitoring. The key findings from this study include the following: (1) sheet pile abutment bridges provide an effective solution for LVR bridges, (2) the measured stresses and deflection were different from the assumed where the differences reflect conservatism in the design and the complex field conditions, and (3) additional research is needed to optimize the design.

Modified Sheet Pile Abutments for Low-Volume Road Bridges: Tech Transfer Summary, January 2012

Iowa has about 22,936 bridges on low-volume roads (LVRs). Based on the National Bridge Inventory data, 22 percent of the LVR bridges in Iowa are structurally deficient, while 5 percent of them are functionally obsolete. The substructure components (abutment and foundation elements) are known to be contributing factors for some of these poor ratings. Steel sheet piling was identified as a possible long-term option for LVR bridge substructures; but, due to lack of experience, Iowa needed investigation with regard to vertical and lateral load resistance, construction methods, design methodology, and load test performance. This project was initiated in January 2007 to investigate use of sheet pile abutments. *************Tech Transfer Summary. For full report see: http://publications.iowa.gov/id/eprint/14832*************

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

Weekly letting report.

Laboratory and Field Testing of an Accelerated Bridge Construction Demonstration Bridge: US Highway 6 Bridge over Keg Creek, RB02-012, 2013

The US Highway 6 Bridge over Keg Creek outside of Council Bluffs, Iowa is a demonstration bridge site chosen to put into practice newly-developed Accelerated Bridge Construction (ABC) concepts. One of these new concepts is the use of prefabricated high performance concrete (HPC) bridge elements that are connected, in place, utilizing advanced material closure-pours and quick-to-install connection details. The Keg Creek Bridge is the first bridge in the US to utilize moment-resisting ultra-high performance concrete (UHPC) joints in negative moment regions over piers. Through laboratory and live load field testing, performance of these transverse joints as well as global bridge behavior is quantified and examined. The effectiveness of the structural performance of the bridge is evaluated to provide guidance for future designs of similar bridges throughout the US.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, October 15, 2013; With Addendums

Weekly letting report.

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

Weekly letting report.

MEPDG Work Plan Task No. 5: Characterization of Unbound Materials (Soils/Aggregates) for Mechanistic-Empirical Pavement Design Guide, 2009

The resilient modulus (MR) input parameters in the Mechanistic-Empirical Pavement Design Guide (MEPDG) program have a significant effect on the projected pavement performance. The MEPDG program uses three different levels of inputs depending on the desired level of accuracy. The primary objective of this research was to develop a laboratory testing program utilizing the Iowa DOT servo-hydraulic machine system for evaluating typical Iowa unbound materials and to establish a database of input values for MEPDG analysis. This was achieved by carrying out a detailed laboratory testing program designed in accordance with the AASHTO T307 resilient modulus test protocol using common Iowa unbound materials. The program included laboratory tests to characterize basic physical properties of the unbound materials, specimen preparation and repeated load triaxial tests to determine the resilient modulus. The MEPDG resilient modulus input parameter library for Iowa typical unbound pavement materials was established from the repeated load triaxial MR test results. This library includes the non-linear, stress-dependent resilient modulus model coefficients values for level 1 analysis, the unbound material properties values correlated to resilient modulus for level 2 analysis, and the typical resilient modulus values for level 3 analysis. The resilient modulus input parameters library can be utilized when designing low volume roads in the absence of any basic soil testing. Based on the results of this study, the use of level 2 analysis for MEPDG resilient modulus input is recommended since the repeated load triaxial test for level 1 analysis is complicated, time consuming, expensive, and requires sophisticated equipment and skilled operators.

Addendum to a report on a special investigation of the Iowa Department of Transportation for the period January 29, 1994 through June 30, 2013

Addendum to a report on a special investigation of the Iowa Department of Transportation for the period January 29, 1994 through June 30, 2013

Iowa Department of Transportation Major Items - Preliminary Quantity Report, November 19, 2013; With Addendums

Weekly letting report.