Development of ESAL Forecasting Procedures for Superpave Pavement Design

The contents of this report reflect the views of the author who Is responsible for the facts and the accuracy of the data presented herein, The contents do not necessarily reflect the official views or policies of the University of KentuckY, of the Federal HighwaY Administration, or the Kentucky Department of Transportation. This report does not constitute a standard, specification, or regulation.

Section 404 of the Clean Water Act (CWA) mandates that state agencies and other entities perform compensatory mitigation when their activities impair jurisdictional waters. In the Commonwealth of Kentucky, the Kentucky Transportation Cabinet (KYTC) is required to pay in-lieu fees or purchase stream mitigation credits when a roadside ditch is impaired or relocated as part of a road construction project. In-lieu fees and stream mitigation credits are costly, and ditches that have suffered degraded habitat and loss of hydrogeomorphic functionality are treated as total losses when they are impacted by construction and maintenance activities. This raises the question of whether the United States Corps of Engineers (USACE) would be receptive to alternative mitigation and monitoring practices that impose a less stringent financial burden on the Kentucky Transportation Cabinet, but which still comply with CWA regulations. This report discusses methodologies used to evaluate the quality of instream and riparian habitat, Section 404 of the CWA and its implications for mitigation of lost or damaged jurisdictional ditches, and the strategies that have been used by other states to fulfill their Section 404 mitigation requirements. The authors highlight mitigation practices that depart from the norm and which place a less onerous financial burden on state transportation agencies. KYTC officials presented this report’s key findings to the USACE Louisville District Office in January 2015 in an effort to receive approval to experiment with novel restoration techniques. The USACE granted KYTC license to implement these techniques on a project-by-project basis. Before implementation on each project, the Cabinet must receive formal approval from USACE officials. Although this was not the blanket mandate that KYTC hoped for, it indicated the Louisville District is willing to study the effectiveness of alternative mitigation strategies. Despite the Cabinet’s request, USACE officials did not approve a plan to reduce post-restoration monitoring requirements. Kentucky Transportation Center (KTC) researchers suggested that KYTC perform exhaustive monitoring of the performance of completed projects that used alternative mitigation techniques. Having information on the short-, medium-, and long-term performance of these sites could – if the results are promising – pave the way to the wider adoption of alternative mitigation practices and could eventually reduce the level of post-restoration monitoring required by the USACE.

This report addresses issues related to transferring the responsibility for quality control from the Kentucky Transportation Cabinet (KyTC) to construction contractors. Surveys of the KyTC, other state departments of transportation, and Kentucky highway contractors were done to identify the advantages, concerns, and modifications of the Contractor Performed Quality Control (CPQC) program. An advisory committee of experienced KyTC engineers, Federal Highway Administration representatives, and contractor representatives met periodically to identify approaches for handling key issues of the program. Several key topics related to CPQC are presented in this report, with emphasis on quality control/quality assurance (QC/QA) administration, QC/QA procedures, quality acceptance and verification testing, and CPQC training. Specific issues related to CPQC pay items in Kentucky are also discussed. Several recommendations have been proposed to enhance the program. If properly implemented, CPQC can improve a contractor's work performance and help relieve the State's burden for inspection. Additional monitoring of the program is necessary to make further improvements and to include other pay items.

Three recently completed road construction projects were investigated to determine Kentucky Transportation Cabinet (KYTC) effectiveness in implementing project commitments (including environmental commitments). Documentation was obtained from KYTC districts in which the projects were constructed and KYTC officials involved with the projects from planning through construction were interviewed. The projects were inspected to audit completion of project commitments. Key stakeholders (officials of local governments, resource agencies, metropolitan planning organizations, interest groups, and adjacent landowners) were interviewed about the projects. They were asked to grade KYTC for implementation of project commitments using a standard report card format. The findings for these investigations are presented. The auditing procedure employed in this study can be used to rate future KYTC projects, identify problems, and suggest solutions.

The Department of Environmental Analysis at the Kentucky Transportation Cabinet has expressed an interest in feature-recognition capability because it may help analysts identify environmentally sensitive features in the landscape, including those relating to historic preservation, archaeology, endangered species habitat, and geology. LIDAR Analyst and Feature Analyst are a pair of geoprocessing software packages that have been developed by Textron Systems. Using this software, users can use LIDAR data to identify finely-scaled user-specified features. The software’s automated feature extraction saves time that might otherwise be spent manually analyzing images and digitizing features. This report explores the capabilities and accuracy of this software by using LIDAR data to identify sinkholes throughout a small area in Kentucky. This report also discusses an alternative LIDAR-based geoprocessing methodology developed by the Kentucky Geological Society. The method relies on ArcGIS and Python scripting to identify sinkholes. The feasibility and applicability of these methodologies are compared, the workflow for each method is outlined, and the capabilities and limitations of each are noted. Sample results—the identification of sinkholes—from each methodology are presented. The research team found the batch processing capability built into LIDAR and Feature Analyst adequate and beneficial for smaller projects, such as projects that prioritize the extraction of buildings, trees, and forest regions.

The Kentucky Transportation Cabinet’s Division of Planning collects weight data, traffic volume data, and vehicle classification data. These data are used as inputs to determine equivalent single axle loads (ESALs). ESALs are used in the pavement design process to determine pavement thickness. There have been inconsistencies observed during the computation of the ESALs during the past three or four years. These inconsistencies have resulted in a significant inflation in the estimate of ESALs per year, which if used in the design process would result in significantly thicker pavements. For example, the ESALs per truck axle for rural principal arterials and rural minor arterials, between 1998 and 1999, more than doubled from, 0.275 to 0.555. Although there was only a small increase in this number after 1999, the value remained significantly higher than expected. The objective of this research study was to evaluate the weight data collection equipment, on-site calibration procedures, and sampling techniques used by the Division of Planning for the different Aggregate Classes of highways in an effort to standardize procedures used by the Division of Planning to collect weight data.

Many of Kentucky’s two-lane rural roads pose an above average risk for fixed object crashes. In Kentucky, run-off-road (ROR) collisions with fixed objects account for 18.9% of all crashes and 41.6% of fatal crashes. Accordingly, ROR crashes are a significant public safety hazard that must be addressed through judicious investments in safety improvements. Until recently, transportation engineers and planners have mostly leveraged qualitative metrics to prioritize safety investments, however, qualitative methodologies are problematic because they may rely excessively on subjective opinion and intuition. This study applied methodologies and software from the U.S. Road Assessment Program (usRAP) to develop quantitative, objective roadside safety ratings for rural two-lane roads in the state of Kentucky on which 20 or more crashes occurred from 2010 to 2015. Kentucky Transportation Center researchers generated usRAP star rating scores following standard protocols and, to validate the methodology, compared those scores to the number of ROR collisions over the specified interval. Analysis revealed robust correlations between star rating scores (and star ratings) and crash data, justifying their as an objective measure of roadside safety. Researchers also delivered a comprehensive database containing over 126,000 records to the Kentucky Transportation Cabinet, which can be used to examine roadside severity and potentially inform future highway investments.

This report provides two analyses for obtaining a quantitative means of rating the condition of railroad‐highway at‐grade crossings based on their measured roughness. Phase One of this report examined 11 crossings in the Lexington area by use of a laser based inertial profiler from the Kentucky Transportation Cabinet (KYTC) and a Face Rolling Dipstick. Phase Two was a continuation of Phase One with 26 crossings examined using inertial profilers from both the KYTC and the National Center of Asphalt Technology. Objective ratings based on rideability were obtained and wheelpath profiles were measured for each crossing. Several roughness indexes were computed from the measured profiles. A correlation between these indexes and subjective rideability ratings were examined in each study. Analysis of the data showed a tendency of objective ratings to decrease as roughness increases. This study found that highway inertial profilers are not an appropriate tool for determining roughness over short distances such as railroad crossings due to their application for testing of longer distances. It is anticipated that this report will be referenced for future research on this topic.

This study created an information base to improve decisions about the replacement or rehabilitation of historic truss bridges. During the first phase of the research, information on the history and design of the 109 bridges in the study was assembled. With the assistance of historic preservation professionals, 75 of those bridges were selected for further study for their potential for rehabilitation. During the second phase, the KTC research team, engineers from the KYTC bridge division, and 12 highway district engineers, who are responsible for the day-to-day care and maintenance of the bridges, evaluated the condition and functional context of the 75 bridges. The goal was to identify those that are good candidates for preservation through rehabilitation. The district engineers were of the opinion that only 14 of the 75 bridges needed to be replaced. However, there was an additional subset of 13 bridges that, in their opinion, present some significant obstacles to preservation related to functional inadequacy or some other problem with the bridge. The bridge engineers estimated considerably higher levels of effort to preserve these 13 bridges (an average of 7.42 on a 10 point scale) than for the 48 remaining bridges (an average of 3.82 on the 10 point scale).

The study of earth pressure distribution on buried structures has a great practical importance in constructing highway embankments above pipes and culverts. Based on Spangler’s research, the supporting strength of a conduit depends primarily on three factors: 1) the inherent strength of the conduit; 2) the distribution of the vertical load and bottom reaction; and 3) the magnitude and distribution of lateral earth pressures which act against the sides of the structure. Rigid culverts are frequently used in Kentucky for routing streams beneath highway embankments because of rolling and mountainous terrain, numerous streams, shallow depths to bedrock, which creates unyielding foundations, and the necessity of using high fills which create large vertical stresses acting on culverts. As a means of exploring ways of reducing large vertical earth pressures acting on a buried structure, ultra-lightweight geofoam was placed in a trench above a reinforced rigid box culvert in Russell County, KY. This study provides strong evidences from both numerical model analysis and in-situ test data to indicate that geofoam is an ideal elasto-plastic material to reduce vertical load on top of a rigid culvert resting on a rigid foundation. The load on the top of a culvert can be reduced to 20% of traditional design load after 2-ft-thick geofoam is placed on top of it. Results from numerical model are more conservative when compared to actual test data. As much as 57% of settlement from geofoam has been recorded. Stresses on the top of a culvert where geofoam was placed have reached a relatively stable level which is expected at the yield point of the geofoam. This technology can be used in applications which require controlled pressure on rigid underground structure. Whether geogoam is used or not used, the model analysis and test data show that the earth pressure acting on the sidewall does not change significantly. Although the pressure acting on the sidewall is slightly higher when geofoam is used on top of the culvert only, the value is still below the design value used by the Kentucky Transportation Cabinet. Use of geofoam placed in an imperfect trench significantly reduces the vertical stresses acting on the top of the culvert.

Technicians are a vital component to the success of any roadway projects. Unfortunately, the Kentucky Transportation Cabinet (KYTC) is experiencing significant shortages of technicians among all aspects of construction and maintenance. Training and developing the adequate numbers of qualified technicians is a substantial endeavor that requires a comprehensive examination of the adequacy of current training program versus the anticipated skill needs of technicians on future projects. Two questionnaires were developed to identify this gap. One is to investigate the skills and trainings that the Cabinet’s technicians possesses and received, and the second is to investigate the skills and/or knowledge which section engineers believe are required among their technicians. Through the analysis of the two surveys, this research found current training programs in Kentucky could cover most of the necessary knowledge and skills for transportation technicians, although more wide cooperation and reciprocity with outside training agencies should be built. However, current training programs are not sufficient enough to satisfy the future technician training needs, especially in the area of grading, structure, soil and maintenance and environment. The research also found technician’s most favorite training methods are on-the-job and classroom hands-on, but on-the-job training has not become one of the major sources where the Cabinet’s technicians received their training. Inability to help promotion and increase salary, schedule conflict and certificate’s short validness are the major barriers which prevented technician’s training participation.

The Kentucky Transportation Cabinet’s (KYTC) bridge inventory is rapidly aging. As such, the Cabinet needs to identify and implement relevant preventative maintenance (PM) actions to extend the useful service lives of those structures. Maintenance actions, costs, and application interval/repair durability information have been obtained for both cyclical and condition-based bridge PM. Additionally, information rehabilitation actions were acquired from a regional Department of Transportation (DOT) survey and from other literature. As part of this study, the Kentucky Transportation Center (KTC) researchers monitored a KYTC bridge washing project to assess its level of effectiveness and to identify potential improvements. Based upon these tasks, recommended guidance was provided to KYTC for use when implementing bridge PM programs. The guidance includes a discussion of critical PM activities, strategies to adopt training and work documents (i.e., special notes) for contract work, and the implementation of work standards/special operating procedures for work performed by KYTC personnel. This report also includes details on the tools and training KYTC district-level personnel will need and outlines a roadmap for conducting pilot programmatic PM work in several districts.

The Kentucky Transportation Center (KTC) at the University of Kentucky has performed a series of research studies for the Kentucky Transportation Cabinet (KYTC) to monitor various experimental bridge painting projects and conduct investigative work focusing on new paint systems. The research study presented in this report addressed experimental projects in fiscal years 2001 and 2002. KTC and KYTC Project Design Team joint efforts in 2000 into early 2001 centered on the preparation of experimental bridge maintenance painting special notes, preliminary field testing/development of new experimental paint systems and testing of proprietary and KYTC standard specification coatings. The laboratory tests identified candidate coating systems that were subsequently used in the KYTC experimental bridge maintenance painting projects conducted under this study. Developmental work focused on total removal and some overcoating systems. The objectives of experimental project monitoring were to: assess the condition of existing paint systems on bridges prior to maintenance painting, monitor the project throughout completion, note problems, describe problem resolution, appraise the condition of the final product, and report observations and/or conclusions about the project. This report begins with a summary of the coatings testing work undertaken by KTC researchers and the KYTC Project Design Team. The experimental bridge maintenance painting monitoring work is presented for each bridge in the appendices. The overall results/findings of this research study are contained in the Conclusions section of this report.

Public perception of Canada’s energy trade is skewed towards Alberta’s oilsands and pipeline projects; a look at the facts reveals a more complex picture.Over the last decade, growth in Canada’s energy trade has been nothing short of historic. Energy exports have become so significant that the revenue is now equivalent to nearly $9,000 for every Canadian household. And it is only projected to grow much, much larger. While Western Canada leads the industry, every region — including Ontario, Quebec and Atlantic Canada — plays a key role. Today, nearly every province is a net energy exporter. The energy sector also adds much to Canada’s economy, with value-added and productivity higher than nearly every other sector. When it comes to labour compensation, oil and gas extraction is the highest-paying sector in the country, at more than three times the average hourly earnings in the Canadian economy generally, and nearly 50 per cent higher than manufacturing. It is vital that policy debates rely on accurate information; unfortunately, this is not always the case.The often heated rhetoric neglects important aspects of Canada’s energy trade. For example, the type of energy that Canada trades has undergone a dramatic transformation. Ten years ago, natural gas was the largest energy export but today accounts for less than one-tenth of the total. Meanwhile, crude oil exports have more than quadrupled. Even more surprising to many Canadians, and perhaps even policy-makers, is how much energy Canada imports. Even Alberta, with its vast energy reserves, imports a considerable amount of energy. Alberta’s energy imports have grown faster than any other province and will soon exceed Ontario’s, a province more than three times larger with very little of its own oil production.Trade in energy is also intimately tied with Canada’s foreign investment policies. The majority of Canada’s energy trade is in the form of related-party transactions. For example, Suncor exports oil from its Canadian operations to its American refineries to supply its American gas stations. This fact has important implications for Canadian policy: foreign multinational firms are an important and growing part of the country’s rapidly expanding energy trade. Promoting Canada’s energy trade requires lowering investment barriers and creating a predictable and stable investment climate for foreign direct investment. Yet, in practice, Canada has recently shown a tendency for the opposite, with governments blocking the takeover of Potash Corporation by Australia’s BHP Billiton, and announcing, after the takeover of Nexen Inc. by a Chinese firm, that future takeovers would face even greater scrutiny. Foreign investment in Canada’s energy has already begun to fall, feasibly as a result of these increasingly hostile signals.Canada has a great deal riding on the future of its energy industry — an industry that is as economically beneficial as any other, if not more so. It is absolutely crucial that we ensure our energy-trade policies are based on high-quality and objective information; politicized and emotional rhetoric does not help.

In this study, different contents of Nano-silica, 2 wt.%, 4 wt.% and 6 wt.%, have been added to bitumen to modify the physical, mechanical and rheological properties of warm mix asphalt (WMA). WMA is containing 2 wt.% of Sasobit (mixture of long-chain hydrocarbons). Various quality control tests have been carried out to characterize the modified bitumen and WMA. The rheological investigations showed that the complex modulus of base bitumen increases by increasing the percentage of Nano-silica from 2 to 6 wt%. Phase angle and rut factor for the Nano-silica modified bitumen have also decreased significantly. From rheological analysis, 6 wt% Nano-silica has been selected as the optimum content. Results of investigations on the asphalt mixtures demonstrated the fact that by increasing Nano-silica content, the quality of the warm mix asphalt has been improved. By increasing the Nano-silica content, the resilient modulus of WMA has increased; as such, the pavement response under the traffic loading has decreased. By adding Nano-silica to the Sasobit WMA, the depth of cracking has decreased dramatically. So, fatigue life of WMA has been extended in the presence of Nano-silica. Also, the results of wheel tracking test demonstrated that the rutting depth of modified samples have been reduced. The results on WMA showed that 6 wt.% of Nano-silica is the optimum content. This result was in compliance with the rheological investigations.