Civil and Environmental Engineering Commons^™

Evaluation Of Snowplowable Marker Installations, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The first large-scale contracts for the installation of snowplowable markers were awarded in 1984 and 1985. Stimsonite 96 and recessed markers were installed. The objective of this study was to evaluate the performance of the installations. Durability and reflectivity results show that both the recessed markers and Stimsonite 96 markers have performed effectively as snowplowable markers. The recessed markers should continue to be used only on four-lane highways constructed to high geometric standards with the Stimsonite 96 markers installed on the majority of highways.

Thickness Design Curves For Asphaltic Concrete On A 4-Inch Layer Of Dense-Graded Aggregate, Or On 6, 9, Or 12 Inches Of Stabilized Soil, Or For Maximum Utilization Of Dense-Graded Aggregate, Herbert F. Southgate

Kentucky Transportation Center Research Report

No abstract provided.

Evaluation Of Durable Lane Delineation Materials, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of the study was to evaluate the cost-effectiveness of available marking materials by means of field tests and to make recommendations concerning the optimum lane delineation materials based on these tests. Materials tested include 100-percent solid epoxy paint, polyester paint, extruded thermoplastic, 3M Stamark tape, 3M Bisymmetric tape, EPOFLEX, solvent epoxy paint, chlorinated rubber traffic paint, and alkyd traffic paint. The test installations have been in place up to four years. The evaluation concerned the durability, reflectivity, and appearance of the materials. Based on current data, expanded use is warranted for 1) polyester paint on lower-volume asphaltic concrete …

Evaluation Of Durable Crosswalk And Stopbar Marking Materials, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study was to find the most cost-effective durable marking material to provide long-lasting stop bars and crossbars. Three materials were tested: 1) 3M Stamark tape, 2) Prismo preformed tape, and 3) extruded thermoplastic (hydrocarbon and alkyd). The various test installations were in place for between 6 and 30 months.

The alkyd-resin thermoplastic material was found to be the most cost-effective I material. The preformed tapes cost two to three times as much as the thermoplastic material while not providing as durable a material when used in this application.The alkyd-resin material maintained its appearance better than the …

Effects Of Load Distributions And Axle And Tire Configurations On Pavement Fatigue, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

Damage factor relationships for axle and tire configurations are presented. Adjustment factors are provided to account for variations in load distributions within axle groups, distances between axles of a tandem, and variations in tire pressure for both dual and flotation tires.

Properly accounting for accumulated fatigue of a pavement requires a traffic volume, proportions of vehicle styles (classifications) within the of service, estimate of the average damage factor for each classification, reasonable measure of traffic stream, dates and estimates of tire contact pressures.

All adjustment factors presented are based on analyses of a limited number of structures and should be …

Use Of Nondestructive Testing To Prevent Failures Of In-Service Metal Bridges, Theodore Hopwood Ii, Robert C. Deen

Kentucky Transportation Center Research Report

The failure of metal bridges, subject to in-service fracture problems mainly caused by fatigue, may be prevented or minimized by performance of periodic nondestructive testing. Attendant factors that justify funding for such inspections include the potential for bridge failure, the consequences of bridge collapse, risk analyses, and inspection strategies. Factors that affect structural integrity include structural design, construction quality, and service loadings.

Details of a computer/strain-gage system capable of obtaining strain-gage data from critical structural elements are described. Data are processed to determine the stress-range distribution, number of stress cycles, resolved mean stress range, need for structural inspection, critical crack …

Documentation For 1986 Weight-Distance Tax Analyses Using Lotus 1-2-3, Herbert F. Southgate

Kentucky Transportation Center Research Report

No abstract provided.

Evaluation Of A Full-Depth Asphaltic Concrete Pavement, Herbert F. Southgate, Gary W. Sharpe, Mark Anderson

Kentucky Transportation Center Research Report

This study was initiated to verify a newly-developed set of design curves for full-depth asphaltic concrete pavements. Quality control during construction was checked using nuclear density testers, Benkelman beams, and a Road Rater. During the course of this study, an analysis system (predicated upon the elastic theory model) was developed to interpret the dynamic deflections as measured by the Road Rater. The thickness design curves were verified by elastic theory and deflection testing within the accuracy of construction variations.

Measured rut depths were analyzed in terms of potential rut depth resulting from consolidation under traffic due to lack of obtaining …

Nondestructive Evaluation Of Rigid Pavements Using Road Rater Deflections [1986], Gary W. Sharpe, Mark Anderson, Robert C. Deen, Herbert F. Southgate

Kentucky Transportation Center Research Report

Dynamic deflections have been used to determine in-place structural conditions of rigid pavements, based on modifications of principles and experience with the structural evaluation of flexible pavements. Details of the use of elastic layer theory to simulate deflection measurements associated with loadings for the Kentucky Road Rater are presented. Included is an illustration of the use of field deflection measurements to "back calculate" in-place moduli. The procedures are generally iterative and involve matching measured deflections with theoretical deflections. Elastic layer principles have been used to simulate deflections only at the mid slab position. Relationships regarding deflections at other locations on …

Stability Of Embankments On Clay Foundations, Tommy C. Hopkins

Kentucky Transportation Center Research Report

Ninety-one well-documented geotechnical failures are reviewed. The case studies involved the failure of embankments, footings and load tests, excavated slopes, and natural slopes. Seventy-five of the geotechnical failures had been analyzed using total stress analysis. Sixteen of the case failures had been analyzed using effective stress analysis. Based on a review of these case studies, there are discrepancies between predicted and actual stabilities of geotechnical structures and there is a tendency tu overestimate the factor of safety. Differences that may arise between predicted and actual performances are discussed and examined and guidelines are proposed for evaluating the potential of successfully …

Use Of Post Delineators On Interstates, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objectives of this report were to investigate 1) the potential benefits of using flexible posts for post delineators and 2) the possibility of not requiring post delineators on sections of interstate-type highways where recessed markers are installed.

It is recommended that post delineators should only be used when the design curvature is 1.5 degrees or more, and the spacing should be based on the formula given in Table III – 1 of the MUTCD. Data obtained concerning the performance of flexible posts do not support widespread use at this time. A testing program should be developed to obtain an …

Treatment Of Narrow Medians On Four-Lane Rural Roadways, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to investigate alternatives to paved mountable medians that have been used in the past on sections of four-lane, partially controlled access roads where right-of-way is restricted. These mountable medians present obvious operational problems due to the 3-inch difference in height as compared to the through lanes. In addition, construction and maintenance problems are associated with mountable medians because of the height differential.

A telephone survey of 16 states was conducted to determine their policy for separation of rural four-lane roads with partial control of access and narrow medians. Accident analyses comparing roads in Kentucky …

Delineation Of Horizontal Curves, Kenneth R. Agent, Tom Creasey

Kentucky Transportation Center Research Report

The objective of this study was to investigate the ability of various traffic control measures to delineate horizontal curves so drivers would perceive the curve and slow to an appropriate speed and then be provided guidance through the curve. Pavement delineation (raised pavement markers, transverse stripes, or rumble strips) and shoulder delineation (post delineators and chevron signs) were used. A laboratory test found that a post delineator configuration in which the distance from the post to the pavement edge and the post spacing remained constant while the height of the delineator on the post increased made a curve appear sharper …

Traffic Accident Rates In Kentucky (1984), Kenneth R. Agent

Kentucky Transportation Center Research Report

Average accident rates, using 1984 accident data only as well as combined 1980 through 1984 data, were calculated for Kentucky highways. Comparison of 1984 to combined 1980 through 1983 rates show the rates have remained stable. There was an increase in total accidents and total accident rate in 1984 compared to 1980 through 1983 data while there was a decrease in the fatal accident rate. Several methods of classifying highways were used when calculating average rates. Those rates may be used in the high-accident location identification program. Average and critical numbers of accidents also were determined for use in the …

A Generalized Slope Stability Computer Program: User’S Guide For Hopk-I, Tommy C. Hopkins

Kentucky Transportation Center Research Report

Data entry and operation of a generalized slope stability computer program are described. The computer program is based on a new approach to formulating and solving the slope stability equilibrium equations. The moment equation as well as the horizontal and vertical equilibrium equations are considered in the model. The purpose of the study was to implement the new approach. The computer program may be used to compute the factor of safety of slip surfaces of arbitrary shape and circular slip surfaces. Effective stress and total stress conditions may be analyzed. Four options are available for computing pore pressures. Both piezometric …

Workshop On Roadway And Street Drainage, Ronald D. Hughes, David L. Allen

Kentucky Transportation Center Research Report

No abstract provided.

The Feasibility Of Draglines For Mine Reclamation, Mark Anderson

Kentucky Transportation Center Research Report

Draglines are presented in this paper as an alternative for mine reclamation in steep sloping areas. Some abandoned mines in steep sloping areas of Kentucky have unreclaimed slopes which pose safety problems, as well as environmental and aesthetic problems. In addition, many active mines in steep sloping areas of Kentucky have slopes which must be reclaimed in the near future. Current methods of slope reclamation in Kentucky typically involve traditional heavy equipment. The current methods are not cost efficient in some cases, and are not safe in some applications.

The paper includes a history of draglines. Early development is summarized, …

Estimation Of Equivalent Axleloads, John A. Deacon, Jerry G. Pigman, Jesse G. Mayes

Kentucky Transportation Center Research Report

The primary objective of this research study was to develop a procedure for estimating equivalent axle loads for purposes of flexible-pavement design. Maximum use was made of historical data and well-accepted procedures were used in developing the prediction model. A series of computer programs was developed to summarize truck-weight and classification data such that traffic characteristics could be estimated from a matrix of data classified by geographic area, Federal highway system, volume, and extent of coal haulage. An equation was developed with the following seven parameters as independent variables; 1) annual average daily traffic volume, 2) average fraction of trucks …

A Computerized Analysis Of Flexible Pavement Rutting Behavior (Pavrut), David L. Allen, Robert C. Deen

Kentucky Transportation Center Research Report

The behavior of asphalt-bound layers, unbound aggregate bases, and foundation soils (subgrades) may be affected by such variables as gradation, asphalt and (or) moisture contents, type of aggregate, density, method of compaction, temperature, magnitude and frequency of loading, duration of each load cycle, and other less significant variables. The complex interaction of all these variables yields a composite behavior for a particular pavement structure that could become manifest in some form of distress or even complete "failure."

Flexible pavements are susceptible to rutting. But it is not well known where and to what extent rutting takes place within a pavement …

Jefferson Freeway Investigation (Westbound Lanes), Herbert F. Southgate, Gary W. Sharpe, Theodore Hopwood Ii, James H. Havens, Mark Anderson, David Q. Hunsucker, Robert C. Deen

Kentucky Transportation Center Research Report

The Kentucky Transportation Research Program (KTRP) was retained to perform an investigation for the Kentucky Department of Highways to assess damage that may be attributed to passage of the Model 992C over portions of the Jefferson Freeway. KTRP investigators conducted visual surveys, performed Road Rater deflection tests, did in-place California Bearing Ratio (CBR) testing on subgrade materials, obtained pavement cores, and conducted laboratory tests and analyses.

It appeared the pavement was damaged by the front-end loader. No evidence of damage to the bridges attributable to the front-end loader was detected. Damage to the pavement attributable to passage of the front-end …

Evaluation Of Stone Column Stabilized Embankment Foundation, Bobby W. Meade, David L. Allen

Kentucky Transportation Center Research Report

The purpose of this study was to document construction procedures, monitor field performance, and make recommendations concerning the effectiveness and future use of a foundation improvement procedure using stone columns for stabilization. This effort was executed by use of field inspections and photographs, instrumentation to monitor foundation and field responses and laboratory analyses of existing and possible conditions.

Instrumentation included earth pressure meters, a multipoint settlement gage, a horizontal slope inclinometer, a settlement platform and vertical slope inclinometers. Settlement of the foundation after column construction was found to be approximately 8 inches as compared to a predicted total settlement of …

Suggested Changes To Kentucky Statutes (Vehicle Weights And Dimensions), Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

The purposes of this report are: 1. To clearly define the terms ''tandem," "tridem," and “triaxle." 2. To clearly define the term "600 pounds per inch width of tire" as the "width of the tread in contact with the pavement." 3. To make the axle load limits the same throughout the statutes. 4. To suggest elimination of indentified discriminatory legislation. 5. To recommend additional legislation: a. to clearly define the purpose and use of "air-bag" suspension systems -- those that can be raised or lowered by the driver, and b. to enable vehicle weight enforcement officers to use shipping documents …

A Survey Of The States On Problems Related To Bridge Approaches, David L. Allen

Kentucky Transportation Center Research Report

A questionnaire was sent to the states concerning problems with bridge approaches. Seven questions were included in the survey, including questions on the use of integral end bents and spread footers. This report summarizes the responses. Appendix A contains the detailed responses received, and Appendix B contains specifications and standard drawings used by some of the states.

Impact Evaluation Of The Traffic Alcohol Program In Lexington, Kentucky, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

This report is an evaluation of increased police enforcement to reduce alcohol-related accidents in Lexington-Fayette County, Kentucky. Three types of data were coIlected as a means of evaluating the Traffic Alcohol Program; accident data, arrest and adjudication data, and cost-effectiveness data.

Results from before-and-after comparisons and time-series analysis show alcohol related accidents decreased significantly during the study period. When comparing two years before with three years during the increased enforcement, the percent reduction in alcohol-related accidents was 28.1 percent using standard before and after analysis and 29.1 percent using time-series analysis. During the same time period, alcohol related fatal or …

Demonstration And Preliminary Evaluation Of The Acoustic Emission Weld Monitor, Theodore Hopwood Ii, Robert C. Deen

Kentucky Transportation Center Research Report

This report describes the demonstration and preliminary evaluation of the microprocessor-based acoustic emission weld monitor (AEWM) developed for the Federal Highway Administration by GARD Inc. of Niles, IL. The equipment was tested successfully on butt welds in several fabrication shops by the Kentucky Transportation Research Program (KTRP). Some problems were encountered in monitoring fillet welds.

The AEWM was demonstrated to personnel from 20 state agencies representing FHWA Regions 1, 3, 4, and 5. The demonstrations were performed at three different fabrication shops in Pennsylvania, Georgia, and Wisconsin.

A preliminary evaluation of the AEWM is included. Also, the summary of a …

Evaluation Of Construction Zone Pavement Marking Materials, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objectives of this report were to evaluate all available foil-back and removable tapes as well as construction zone raised pavement markers and to recommend materials that should be included on approved lists for use by the Kentucky Department of Highways. The tapes were placed on transverse test sections and as lane lines and the reflectivity, durability, and appearance were observed. The markers were observed at test sections as well as at construction sites.

Lists of tapes to be included on the approved lists for foil-back and removable tapes were recommended. Tapes manufactured by 3M and Flex-0-Lite were included on …

Latex-Concrete Overlays On Bridge Decks (I64, Mp 150 To West Virginia Line), James H. Havens, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Visual field inspections and soundings were performed on latex concrete overlays on 24 bridges on I 64 between Milepoint 150 and the West Virginia state line. The inspections were conducted in response to a request from the Kentucky Department of Highways to determine if cracking problems in the overlays were related to workmanship or materials.

The field inspections revealed that most of the overlay crack problems were related to 1) reflection cracking caused by pre-existing fractures in underlying concrete bridge decks and 2) “pull-in” cracks in the overlay, caused by belated tyning of the bridge deck.

Field diaries, inspection reports, …

1985 Safety Belt And Child Safety Seat Usage Rates In Kentucky And Evaluation Of A Public Information Campaign, Kenneth R. Agent

Kentucky Transportation Center Research Report

Two objectives of the survey are summarized in this report. One was to establish 1985 safety belt and child safety seat usage rates in Kentucky and compare those to 1982, 1983, and 1984 rates. The other was to evaluate the effectiveness of public information campaigns as a means of increasing safety belt and safety seat usage rates.

Statewide usage rates in the 19 cities previously surveyed in 1982, 1983, and 1984 indicated that driver safety belt usage had increased to 9.2 percent in 1985 while the child safety seat and belt usage rate of 29.1 percent remained at the 1984 …

Traffic Trends And Their Relationship To Highway-Use Revenues, Jerry G. Pigman, Manouchehr Vaziri

Kentucky Transportation Center Research Report

With increasing concerns about the present level of highway funding, this study was initiated to investigate historical trends and to develop predictive methodologies for considering alternatives available for increasing highway revenues. Emphasis was placed on historical trends, and a data base of highway-related and socio-economic variables were prepared to document the relationship between these variables and highway-user revenues. A historical file of 37 variables was prepared for the period 1964 through 1984.

As a means of investigating future alternatives that will affect highway-user revenues, a series of nine equations or models were developed that represented historical data. Input data necessary …

Guidelines For The Use Of Protected/Permissive Left-Turn Phasing, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to develop guidelines that may be used to aid the traffic engineer in deciding whether protected/permissive (permissive) phasing is appropriate to use at a given location. An inventory identified 58 intersections in Kentucky where permissive phasing was used. Characteristics of these intersections were related to accident data to determine the effect permissive phasing has had on p.eft-turn and total accidents.

Left-turn accidents increased dramatically when permissive phasing replaced protected-only (exclusive) phasing and when it was used at approaches where the speed limit was over 45 mph. There were no substantial changes in left-turn and …