Illinois Highway Materials Sustainability Efforts of 2014

This report presents the 2014 sustainability efforts of the Illinois Department of Transportation (IDOT) in recycling reclaimed materials in highway construction. This report meets the requirements of Illinois Public Act 097-0314 by documenting IDOT’s efforts to reduce the carbon footprint and achieve cost savings through the use of recycled materials in asphalt paving projects. Research efforts undertaken and those that will have a future impact on IDOT’s sustainability efforts are highlighted.Illinois Department of Transportation, R27-160Ope

Baseline Rolling Resistance for Tires’ On-Road Fuel Efficiency Using Finite Element Modeling

Calculation of truck tires rolling resistance, using the finite element method and considering variables such as incompressible visco-hyperelastic rubber materials, accurate tire geometry and steady temperature distribution, is presented. The model was validated using experimentally measured contact area and contact stresses. Rolling resistance was calculated for three values of axle load, tire inflation pressure, temperature and speed. In addition, regression analysis was used to propose a mathematical expression for predicting rolling resistance as a function of the considered variables. Finally, the contribution of tire’s rubber components to the internal energy was quantified, and it was found that sidewall and subtread were the most relevant. The results of this study will help differentiate the contribution of pavement parameters, such as mean profile depth and international roughness index, to fuel efficiency

Development of Domain Analysis for Determining Potential Pavement Damage

A new approach for quantifying flexible pavement damage potential is proposed. The new method, domain analysis, utilizes multiaxial results from advanced finite element models to calculate the response of flexible pavements to tire loading. The output is a single scalar value, which is unique to a given pavement structure and loading configuration. The ability of the domain analysis to quantify bulk damage potential and overcome flaws of conventional approaches based on point responses is demonstrated by testing three case studies: (1) comparison of typical loading conditions of dual-tire assembly (DTA), new-generation wide-base tire (NG-WBT), and steer tire; (2) effect of tire-inflation pressures; and (3) influence of differential tire-inflation pressure for DTA. The proposed method provides a direct link between three-dimensional contact stresses at the tire-pavement interface and three-dimensional responses of a loaded pavement structure. Also, the applicability of the domain analysis method could easily extend to other pavement structures, tire types and configurations, and loading conditions, along with considering other failure criteria. Jaime Hernandez was affiliated with University of Illinois at Urbana–Champaign at the time of publication

Revised Condition Rating Survey Models to Reflect All Distresses: Volume 1

Pavement condition assessment plays a key role in infrastructure programming and planning processes. Similar to other state agencies, the Illinois Department of Transportation (IDOT) has been using a system to evaluate the condition of pavements since 1974. Since 1994–1995, IDOT has been using a system to project future pavement performance as well. The condition rating survey (CRS) value is the index between 1 (failed) and 9 (new), representing the overall condition of pavement. The purpose of this study was to update and revise the existing CRS calculation and prediction models using new data. To accomplish the goals of the study, the CRS data was received for the years 2000–2014. The data was initially processed and cleaned in preparation for modeling. CRS prediction models were prepared for Interstate and Non-Interstate pavement types. The two-slope model was used for all asphalt-surfaced pavements, whereas a new model was proposed for concrete-surfaced pavements. The proposed model for concrete-surfaced pavements is a nonlinear survival type designed to capture the distinct deterioration patterns of concrete pavements with little to no reduction in CRS—followed by a rapid and linear deterioration and a flatter region at the end, once the pavement is saturated with damage. The CRS calculation models were updated to incorporate new distresses. Based on the literature review and the analysis of distress composition, it was found that IDOT’s distress ratings are generally in agreement with the ASTM standard—with the exception of alligator cracking. A database containing recorded distresses, used by experts, was referenced to add missing distresses, such as alligator cracking, for each Interstate model.IDOT-R27-150Ope

A case of camptocormia (bent spine) secondary to early motor neuron disease

Abstract. Camptocormia is a gait disorder, characterized by hyperflexion of thoracolumbar spine which increases on walking, and disappears in the supine position. A 48 year-old man developed progressive gait deterioration for one year and slight weakness and tremor of both hands for five months. It eventually became apparent that the patient had motor neuron disease, as well as symptoms of extrapyramidal disorder

Development of Pavement Performance Prediction Models for Preservation Treatments: Volume 2

The implementation of a pavement preservation program was initiated in Fiscal Year (FY) 2005 at the Illinois Department of Transportation (IDOT) by appropriating funding for four specific pavement preservation treatments. The types of treatments included micro-surfacing, slurry seals, cape seal, and bituminous surface treatments (also known as chip seals). The scope and funding level for the state’s nine highway districts has expanded over the years. As a result, several years of performance data was collected from the projects constructed since the inception of the program. In this study, the performance of preservation treatments used by districts as part of the pavement preservation program were evaluated. After treatments were applied, pavement condition prediction models were developed for nine preservation treatments. Two methodologies were followed in developing the models. The first is solely based on the collected data when historical pavement condition data were sufficient. Due to the lack of data for many of the treatments, an alternative method was used to develop models. A multi-criteria decision-making method known as the analytic network process (ANP) was used to integrate expert opinion collected through questionnaires into the model development. The proposed model form is consistent with the existing condition rating survey CRS prediction models with a single slope, with the addition of project-specific factors to adjust the deterioration rate. The model variables included the existing pavement condition prior to the treatment, traffic, and truck percentage, along with the base deterioration rate. According to the modeling results, chip seals, slurry seals, and Half-SMART treatments were among the shortest-lived treatments, with an average service life of 3–4 years. For micro-surfacing treatments, single-pass and double-pass, could extend the service life to approximately 6 and 7 years, respectively. The average service life extension for cape seal treatment was more than 7 years, whereas cold in-place recycling treatment, with surface overlay and surface treatment, can extend pavement service life by approximately 8–10 years. It was also found that the performance of the ultra-thin bonded wearing course UTBWC treatment can be comparable to that of the micro-surfacing treatments, by extending the pavement service life by 6 years on average with a wider range of variability.IDOT-R27-150Ope