Evaluation, Selection and Planning the Implementation of a Pavement Management Optimization Model, Phase II Report, 1994

The missions of the research are to assist the Iowa Department of Transortation (Iowa DOT) to: Define pavement management (PM) optimization; Identify the characteristics of PM optimization systems being developed or implemented; Identify specific and achievable objectives for the Iowa DOT pavement management optimization; Evaluate different PM optimization methodologies; Identify a methodology to perform PM optimization that best satisfies the Iowa DOT's objectives; Develop a plan for the implementation of the PM optimization selected. The project is divided into three (3) phases. The first phase has been completed and accomplished the first three missions (identified above). The second phase has been completed and accomplished the next two missions. Phase three will accomplish the last mission.

Ultra Thin PCC Overlays, HR-559, Construction Report, 1995

A 11.6 km (7.2 mi.) portion of IA 21 in Iowa County from the junction of US 6 north to the junction of IA 212, was selected for the research project. The project was divided into 65 different test sections of a PCC overlay of an existing asphalt concrete (AC) surface with thicknesses of 50 mm (2 in.), 100 mm (4 in.), 150 mm (6 in.), and 200 mm (8 in.). The joint spacings for these sections were 0.6 m (2 ft.), 1.2 m (4 ft.), 1.8 m (6 ft.), 3.7 m (12 ft.), and 4.6 m (15 ft.). Joints were sealed if the thickness of the pavement was over 100 mm (4 in.), unless specified. Two types of polypropylene fibers, monofilament and fibrillated, were added to the conventional PCC mix for designated sections. Three additional sections consisted of an asphalt overlay for comparison with the concrete overlay. Three different base preparations were used on the project, consisting of: patching and scarifying, patching only, and cold-in-place recycling. Sensors were placed in various test sections to measure the temperature and strain during and after construction of the overlay. Pullout tests were also conducted at various locations. Beams cylinders were made for each of the PCC mixes and tested for flexural and compressive strengths. Evaluation of the performance will be conducted through December 31, 1999.

Study of Alternate Pavement Designs, 1968

This report is submitted pursuant to a contract dated August 30, 1967, between the Iowa State Highway Commission and Howard, Needles, Tammen & Bergendoff, Consulting Engineers, in connection with studies determining (11,A) alternate pavement designs, and (11,B) criteria for geometric design studies. Included herein is that portion of the report covering Paragraph 11,A, comprising preparation of alternate type pavement designs (Portland Cement and Asphaltic Concrete) for the Cedar Valley Freeway and proposed US-518 from 1-80 to US-30. These alternate pavement designs consider quality and availability of aggregates, soil conditions and traffic information, to determine details and dimensions of pavement design. Comparative cost studies were prepared from alternate design data and recommendations as to pavement type are presented for Commission review.

Preliminary Assessment of the Potential Use of Alternative Materials for Concrete Highway Pavement Joints, 1997

The overall objective of the work contained in this paper is to identify background information on the use of load-transfer devices in highway pavement joints and to provide a preliminary assessment of the market potential for use of alternative materials in that capacity. The intent of the authors is to provide a concise compilation of information upon which HITEC personnel may judge whether or not the use of alternative materials for concrete highway pavement joints is worth a more thorough and rigorous evaluation.

Impact of Curling and Warping on Concrete Pavement, TR-668, 2016

Portland cement concrete (PCC) pavement undergoes repeated environmental load-related deflection resulting from temperature and moisture variations across the pavement depth. This phenomenon, referred to as PCC pavement curling and warping, has been known and studied since the mid-1920s. Slab curvature can be further magnified under repeated traffic loads and may ultimately lead to fatigue failures, including top-down and bottom-up transverse, longitudinal, and corner cracking. It is therefore important to measure the “true” degree of curling and warping in PCC pavements, not only for quality control (QC) and quality assurance (QA) purposes, but also to achieve a better understanding of its relationship to long-term pavement performance. In order to better understand the curling and warping behavior of PCC pavements in Iowa and provide recommendations to mitigate curling and warping deflections, field investigations were performed at six existing sites during the late fall of 2015. These sites included PCC pavements with various ages, slab shapes, mix design aspects, and environmental conditions during construction. A stationary light detection and ranging (LiDAR) device was used to scan the slab surfaces. The degree of curling and warping along the longitudinal, transverse, and diagonal directions was calculated for the selected slabs based on the point clouds acquired using LiDAR. The results and findings are correlated to variations in pavement performance, mix design, pavement design, and construction details at each site. Recommendations regarding how to minimize curling and warping are provided based on a literature review and this field study. Some examples of using point cloud data to build three-dimensional (3D) models of the overall curvature of the slab shape are presented to show the feasibility of using this 3D analysis method for curling and warping analysis.

Iowa City: Apartment & Condominium Recycling, January 30, 2015

The city of Iowa city is continually working to improve the community's recycling services and options. The city services about 15,000 households, single family home and multifamily homes with four units or fewer with curbside pick ups of refuse, dual-stream recycling and yard waste as well as electronics and bulky waste by appointment.

Iowa State Park Recycling Research Study, 2012

The Department of Natural Resources’ mission of “Leading Iowans in caring for our natural resources” provides the framework within which the Iowa State Park Recycling Research Study was conducted. Recycling at home and in places of business is becoming common for most Iowans but recycling is not available in any form at most Iowa State Parks. The Iowa State Park Recycling Research Study was undertaken to determine the amount of solid waste generated, primarily by campground guests, and how much of this waste is locally recyclable. The study also looked at existing solid waste hauling contracts and the location of area recycling centers. Based on data collected, recommendations are made regarding the economic and operational viability of implementing recycling in the eight (8) state parks participating in the study.

Report Recycled Content Plastic Bag and Soy Inks, Iowa Department of Transportation, 2003

Report to Margaret Thompson, Chief Clerk, about Recycled Content Plastic Bag and Soy Inks.

Report Recycled Content Plastic Bag and Soy Inks, Iowa Department of Transportation, 2002

Report to Margaret Thompson, Chief Clerk, about Recycled Content Plastic Bag and Soy Inks.

Waste Matters, July 2003

Newsletter for Department of Natural Resources, Waste Management Division

Waste Matters, May 2004

Newsletter produced by Department Natural Resources, Waste Managment Division

Waste Matters, September 2004

Newsletter prdouced by Department of Natural Resources, Waste Matters Division

Waste Matters, January 2004

Newsletter produced by Department of Natural Resources, Waste Management Division

Recycled Content Plastic Bag and Soy Inks Report, 2004

Report to Margaret Thompson, Chief Clerk, about Recycled Content Plastic Bag and Soy Inks.

Evaluation of Different Methods to Calculate Heavy-Truck VMT, Final Report, December 2004

Reliable estimates of heavy-truck volumes are important in a number of transportation applications. Estimates of truck volumes are necessary for pavement design and pavement management. Truck volumes are important in traffic safety. The number of trucks on the road also influences roadway capacity and traffic operations. Additionally, heavy vehicles pollute at higher rates than passenger vehicles. Consequently, reliable estimates of heavy-truck vehicle miles traveled (VMT) are important in creating accurate inventories of on-road emissions. This research evaluated three different methods to calculate heavy-truck annual average daily traffic (AADT) which can subsequently be used to estimate vehicle miles traveled (VMT). Traffic data from continuous count stations provided by the Iowa DOT were used to estimate AADT for two different truck groups (single-unit and multi-unit) using the three methods. The first method developed monthly and daily expansion factors for each truck group. The second and third methods created general expansion factors for all vehicles. Accuracy of the three methods was compared using n-fold cross-validation. In n-fold cross-validation, data are split into n partitions, and data from the nth partition are used to validate the remaining data. A comparison of the accuracy of the three methods was made using the estimates of prediction error obtained from cross-validation. The prediction error was determined by averaging the squared error between the estimated AADT and the actual AADT. Overall, the prediction error was the lowest for the method that developed expansion factors separately for the different truck groups for both single- and multi-unit trucks. This indicates that use of expansion factors specific to heavy trucks results in better estimates of AADT, and, subsequently, VMT, than using aggregate expansion factors and applying a percentage of trucks. Monthly, daily, and weekly traffic patterns were also evaluated. Significant variation exists in the temporal and seasonal patterns of heavy trucks as compared to passenger vehicles. This suggests that the use of aggregate expansion factors fails to adequately describe truck travel patterns.