Engineering Commons^™

A Possible Explanation Of Concrete Pop-Outs, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

This report summarizes several years of research relating to damage to concrete and aggregates undergoing freezing and thawing. Basic principles involving freezing and attendant pressures are considered. Application of these principles to the evaluation of concrete was accomplished in experiments on concrete having low and high air contents.

Freeze-thaw characteristics of saturated aggregates relative to physical properties such as porosity, absorption, and bulk specific gravity were studied by submerging individual particles in pre-chilled mercury. Pressures associated with pop-outs in concrete were monitored and are presented along with accompanying theoretical considerations.

Raised-Aggregate, Lane-Delineation Stripe, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

Experimental raised-aggregate (1/2 inch (13 mm) to 1 inch (25 mm)) traffic stripes were installed on approximately 0.4 mile (644 m) of US 60 just north of the intersection with US 421 in Franklin County. Installation was during June 1974. Aggregate stripes were painted yellow and used as skip lines inside the continuous channelization stripes to indicate no crossing into the two-way, left-turn lane except for turning movements.

Observations indicated that the raised-aggregate stripes had good durability after being exposed to 2 years of wear. During dry, nighttime conditions, the paint stripes were slightly more effective than the aggregate stripes; …

Statewide Survey Of Skid Resistances Of Pavements [Dec. 1976], Rolands L. Rizenbergs, James L. Burchett, Larry A. Warren, William M. Sampson

Kentucky Transportation Center Research Report

Since 1969, when a research-type, skid-test trailer was acquired, U.S. routes were surveyed in 1970 and 1971, and the interstate and toll road systems were surveyed in 1971. The data were used for research purposes and have been reported. The interstate and toll road systems were surveyed again for research purposes in 1974. Since October 1974, surveys have been performed under a highway safety project grant. All primary and principal secondary roads, involving 4,612 miles (7425 km), were surveyed in 1975. The 1974 and 1975 surveys, data reported herein, represented 25 percent of the mileage of rural, state-maintained roads in …

Modification Of Kentucky’S Adequacy-Rating Techniques, Charles V. Zegeer, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The purpose of this study was to evaluate Kentucky's adequacy-rating methods and procedures and to recommend improvements. The rating procedures used by planning engineers in the highway districts were found to be reliable and consistent. Kentucky's methods were found to be superior to methods used in most states, but several changes are recommended. Additions include credits for accident analysis for urban and rural sections, traffic control devices for urban areas, and traffic safety features for bridges. Skid resistance evaluation was changed from a subjective rating to a measured value. Points assigned to the various rating elements have been revised, and …

Accidents On Rural, Two-Lane Roads And Their Relation To Pavement Friction [Nov. 1976], Rolands L. Rizenbergs, James L. Burchett, Larry A. Warren

Kentucky Transportation Center Research Report

Friction measurements were made with a skid trailer at 40 mph (18 m/s) on 1460 miles (2350 km) of rural, two-lane roads (US routes) in Kentucky. Maintenance sections or subsections were treated as test sections. Accident experience, friction measurements, traffic volumes, and other available data were obtained for each. Various expressions of wet-pavement accidents and pavement friction were related and analyzed. Averaging methods were used in developing trends and minimizing scatter. A moving average for progressively-ordered sets of ten test sections and test sections grouped by Skid Numbers and Peak Slip Numbers yielded more definite results. The expression of accident …

Acoustic Emission, Fatigue, And Crack Propagation, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Acoustic emission was used in conjunction with tensile tests to evaluate the condition of structural steel specimens subject to various tensile fatigue lives. The results indicate that the acoustic emissions detected were the result of plastic deformation. There was no apparent relationship between fatigue history of the steel specimens and the amount of plastic deformation they can accommodate.

Further tests revealed that acoustic emission has the physical capability of detecting cracks on large structural steel members. This may prove beneficial for the comprehensive testing of steel bridges.

Kentucky Research: A Flexible Pavement Design And Management System, Herbert F. Southgate, Robert C. Deen, James H. Havens, William B. Drake

Kentucky Transportation Center Research Report

Various strategies for designing pavement structures are discussed. Initial full-life design, stage designs and planned extensions of service life, final design, surface renewals for deslicking, no-defect designs for high-type high-volume facilities, and allowable-defect designs are considered. Economics enter in terms of salvage value of existing pavements and alternate designs using different proportions of materials within the structure.

The elastic model represented in Chevron's n-layered computer program is the basis for theoretical relationships. Ranges of values are given for input variables such as Young's moduli, Poisson's ratio, thicknesses for layers, tire pressure, and load. The Kentucky CBR is related to modulus …

Cross Florida Barge Canal Restudy Report Summary, Department Of The Army Jacksonville District Corp Of Engineers

Waterways and wildlife

The objective of this study was to prepare a Restudy Report including an environmental assessment and analysis, engineering and cost studies, and updated economic studies on various alter natives for the Cross Florida Barge Canal Project. Detailed engineering, economics and environmental results are presented in separate documents and summarized herein. An environmental impact statement was prepared to accompany the Restudy Report. The basic framework for the studies was regional in scope and included baseline conditions as well as future conditions expected with and without the alternatives studied. Study area delineation was based upon the economic , social, and environmental systems …

Development Of Warrants For Left-Turn Phasing, Kenneth R. Agent

Kentucky Transportation Center Research Report

Warrants for the installation of left-turn phasing were developed. A review of literature was conducted along with a survey of the policies of other states. Field data of delays and conflicts were taken before and after installation of exclusive left-turn signalization. Left-turn delay studies were conducted at intersections with varying volume conditions. Analysis of the effect on accidents of adding a left-turn phase was made. The relationship between left-turn accidents and conflicts was investigated. Other types of analysis concerning gap acceptance, computer simulation, capacity, and benefit-cost ratios were also performed.

It was found that exclusive left-turn phasing significantly reduced left-turn …

Effect Of Pavement Texture On Traffic Noise, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

Noise from highway vehicles emanates primarily from engine exhausts, tire-pavement interaction) gears, and rattles. Studies have shown that at high speeds tires become the dominant generators of noise. Measurements on different road surfaces have produced different noise-versus-speed relationships (1). This led to the road surface adjustment used in the noise prediction procedure developed in NCHRP Report 117 (2). This adjustment called for a 5 dBA reduction for smooth surfaces (very smooth, seal-coated asphalt pavement) and a 5 dBA increase for rough surfaces (rough asphalt pavement with voids 1/2 inch (12 mm) or larger in diameter and grooved concrete). …

Freeze-And-Thaw Of Concretes And Aggregates, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

This report summarizes several years of research relating to damage to concrete and aggregates undergoing freezing and thawing. Basic principles involving freezing and attendant pressures are considered. Application of these principles to the evaluation of concrete was accomplished in experiments on concrete having low and high air contents. The effects of air entrainment upon freeze-thaw resistance were demonstrated.

Freeze-thaw characteristics of saturated aggregates relative to physical properties such as porosity, absorption, and bulk specific gravity were studied by submerging individual particles in pre-chilled mercury. Pressures associated with popouts in concrete were monitored and are presented along with accompanying theoretical considerations.

Pedestrian Accidents In Kentucky, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

When a pedestrian is hit by a motor vehicle, he is usually injured or killed; there is no protective cushion to absorb the impact. The high concentration of pedestrians in urban areas, coupled with heavy vehicle traffic, often results in large numbers of pedestrian accidents. In rural areas, there are considerably fewer pedestrians but traffic speeds are higher and, therefore, accidents are more often fatal.

Pedestrian fatalities have increased in the United States from about 7,800 in 1960 to approximately 10,500 in 1973 (1). There are 120,000 pedestrian accidents each year. Total traffic accidents in the US number about …

Highway Accidents At Bridges, Kenneth R. Agent, Robert C. Deen

Kentucky Transportation Center Research Report

Grade-separation structures (bridges) at interchanges, crossroads, over streams, railroads, etc., which are intended to provide greater convenience and safety, otherwise involve features which either obstruct the range of free travel or serve as containment barriers. The objective of this study was to identify those principal features of bridges and appurtenances which may be related to accident frequency and severity and to provide some further insights toward highway safety.

Speed Reduction In School Zones, Charles V. Zegeer, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

The use of flashing beacons together with signing has become somewhat standard throughout the country to alert drivers to the presence of school children and to regulate vehicle speed in school zones. Yellow beacons, usually two flashing alternately, may be used with both warning signs and regulatory signs. The only regulatory signs related to school zones are speed-limit signs. Both hazard identification beacons and speed-limit sign beacons are intended to operate only during hours when the warning and speed regulations are in effect. The effectiveness of signs and flashing lights in reducing speeds in school zones has been questioned.

The …

Evaluation Of The Institute Of Transportation Engineers Program For School Pedestrian Crossing, Nabil Shafiq Hamadeh

Dissertations and Theses

The Technical Council of the Institute of Transportation Engineers (ITE) developed a program for school crossing protection. The intent of this thesis is to evaluate the ITE program within. the context of those programs developed by other agencies throughout the nation. Research materials were obtained from the appropriate Federal, state, local and other agencies through papers, articles, reports and correspondence. Upon the analysis of these sources, the ITE program was found to be deficient in several ways. Recommendations for modifying the program which are set forth herein include a revision of the ITE program including the school route map, clarification …

A Survey Of Use Of Left-Turn-On-Red, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objectives of this survey were to determine the extent that a left turn on a red traffic signal (LTOR) has been used across the country and to learn how effective it has been. Responses were received from 43 of the 55 cities surveyed. Of the cities responding, 22 have either had past experience with LTOR or have recently enacted an ordinance which will allow LTOR in the future. Most LTOR laws limit its use to intersections of two one-way streets. A much higher percentage of cities in the western United States have laws permitting LTOR than cities in the …

Constant-Rate-Of-Strain And Controlled-Gradient Consolidation Testing, C. Thomas Gorman

Kentucky Transportation Center Research Report

Controlled-gradient (CG), constant-rate-of-strain (CRS), and conventional incremental-loading (STD) consolidation testing are compared and evaluated. Undisturbed samples representing three soils common to Kentucky were used in the testing program. Settlements estimated by each testing technique were compared with settlement records from one of the sites. Results of 15 CG, 14 CRS, and 32 STD consolidation tests are shown. No significant differences were noted in values obtained from the three types of consolidation tests. Feasibility of the new test methods for routine testing is briefly discussed and recommendations were made for refinements in testing procedures.

Evaluation Of Thermoplastic Pavement-Striping Materials (Louisville And Jefferson County), Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

Approximately 1,406,100 linear feet (428,579 m) of hot-sprayed thermoplastic stripe was applied to roadways in Louisville and Jefferson County in the summer of 1973. Visual observations of appearance, durability, and night visibility were conducted according to ASTM D 713-69, the standard method for conducting road service tests on traffic paint. Attempts to conduct photometer measurements of the thermoplastic striping were unsuccessful. Visual observations made during rainy, nighttime conditions were also unsuccessful because very little difference was noticeable among the various sections.

The evaluation showed that the thermoplastic stripes performed considerably better on bituminous concrete pavements than on portland cement concrete …

The Socioeconomic Impact Of The Mountain Parkway And Ky 15, Joseph T. Farmer

Kentucky Transportation Center Research Report

A study of socioeconomic variables in a nine-county region in Eastern Kentucky was undertaken to determine whether significant growth had occurred since the opening of the Mountain Parkway and reconstruction of KY 15. It was hypothesized that these roads have acted as catalysts with available resources to promote a better quality of life.

Study revealed that, while income levels and business sales have enjoyed substantial increases, overall quality of life is still poor. Educational facilities are inadequate; economic diversification in business types is limited; coal is still the main stimulant for income and employment. However, outmigration of persons from the …

Accidents On Rural, Two-Lane Roads And Their Relation To Pavement Friction [Apr. 1976], Rolands L. Rizenbergs, James L. Burchett, Larry A. Warren

Kentucky Transportation Center Research Report

Friction measurements were made with a skid trailer at 40 mph (18 m/s) on 1460 miles (2350 km) of rural, two-lane roads (US routes) in Kentucky. Maintenance sections or subsections were treated as test sections. Accident experience, friction measurements, traffic volumes, and other available data were obtained for each. Various expressions of wet-pavement accidents and pavement friction were related and analyzed. Averaging methods were used in developing trends and minimizing scatter. A moving average for progressively-ordered sets of ten test sections and test sections grouped by Skid Numbers and Peak Slip Numbers yielded more definite results. The expression of accident …

Characteristics Of Traffic Streams On Rural, Multilane Highways, Jerry G. Pigman, Jesse G. Mayes

Kentucky Transportation Center Research Report

The purpose of this study was to develop a data base and interrelationships for traffic characteristics on rural, multilane highways. Primary emphasis was placed on factors influencing lane distribution. Other characteristics investigated were vehicle speeds, vehicle classifications, volumes, time distributions of flow, and noise emitted by vehicle type and weight. Most analyses were based on traffic characteristics data collected in the summer of 1973. Analyses of 1968 and 1975 traffic characteristics data were compared with 1973 data for the purpose of investigating unusual trends over the various time periods. The 1968 and 1973 surveys produced similar results; however, some changes …

The D-Cracking Phenomenon: A Case Study For Pavement Rehabilitation, James H. Havens

Kentucky Transportation Center Research Report

No abstract provided.

Guardrail Performance: An Analysis Of Accident Records, Kenneth R. Agent

Kentucky Transportation Center Research Report

Accident records involving guardrails were analyzed and summarized.

Guardrail-related accidents comprised a significant percentage of interstate and parkway accidents, particularly those resulting in fatalities. Guardrail involvement in accidents was much less on primary and secondary highways than on interstates and parkways.

The severity of guardrail-related accidents was higher than the average severity of all accidents. The severity of guardrail-related accidents was higher on the primary and secondary system than on the interstate and parkway system.

Guardrails have not been very successful in redirecting vehicles parallel to traffic. The largest number of severe injuries involved vehicles vaulting over the guardrail Increased …

A Soils Data System For Kentucky, Dwight Spradling

Kentucky Transportation Center Research Report

This report discusses the development of a computerized soils data system which facilitates collection, centralized storage, and retrieval of soils data developed by engineers and scientists for projects in Kentucky. Without such a system, much soils data are essentially lost after each project is completed. This system will provide data that can conveniently be used for developing preliminary sources of information for site investigation, for preparing regional soil maps, for land use planning, and for studying new and existing empirical relationships involving soil properties and characteristics.

Various types of data systems, the design of the system to include software and …

A High-Accident Spot-Improvement Program, Kenneth R. Agent, John A. Deacon, Robert C. Deen

Kentucky Transportation Center Research Report

As a result of an extensive before-and-after accident study, the high-accident location, spot-improvement program in Kentucky, although not a costly program, was found to have significantly decreased the number of motor vehicle accidents. Favorable benefit-cost ratios indicated that the cost of the program has represented a good investment in comparison with the resultant savings in accident costs. The spot-improvement program had little effect on average accident severity as measured by a severity index. Detailed analysis of available accident data showed that, for studies of the type reported, the 12-month period immediately prior to the date of identification of a high-accident …

A Computer Graphics Analysis Of A Freeway Merge Control System, Thomas Alan Risher

Retrospective Theses and Dissertations

In 1975, C.S. Bauer completed a doctoral dissertation at the University of Florida which treated the Green Band Merging Control System on I-75 in Tampa, Florida. In this work, Bauer suggested the possibility for the use of computer graphics as a toll for analysis of the bands generated by the Green Band Control System Simulation developed in his dissertation. The use of computer generated movies of the bands displayed to ramp drivers by the system allows the comparison of various band control strategies without the need for field implementation and testing. With the goal of producing such films in mind, …