Engineering Commons^™

Cracking In Continuously Reinforced Concrete Pavements, James H. Havens, Robert C. Deen, Assaf S. Rahal, Wm. Vernon Azevedo

Kentucky Transportation Center Research Report

The objective of this study was to monitor placement and evaluate performance of continuously reinforced concrete pavement with an emphasis on determining the time of cracking and crack interval. This paper reports on the design and construction practice for CRCP in Kentucky. Data on crack frequency and time of cracking is also included in an attempt to further explain the cracking pattern associated with CRCP.

Constant-Rate-Of-Strain And Controlled-Gradient Consolidation Testing, C. Thomas Gorman, Tommy C. Hopkins, Robert C. Deen, Vincent P. Drnevich

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 of tbree soils common to Kentucky were used in the testing program. Results of 15 CG, 14 CRS, and 32 STD consolidation tests are evaluated. Feasibility of the new test methods for routine testing is briefly discussed and recommendations are made for refinements in testing procedures.

An Investigation Of Low Cylinder-Strengths (District 6), Assaf S. Rahal

Kentucky Transportation Center Research Report

District 6 has had a lingering problem of low cylinder-strengths. This report describes, in detail, an ensuing investigation which incorporated the use of identical materials of concretes used in District 6 and analyses of cylinder data, in situ concrete cores, and laboratory mixtures. The investigation revealed that a high percent of the in situ concrete is sound and reliable, and that aggregate type and (or) air content were not the cause for the low cylinder-strengths. The quality of making, storing, and curing the cylinders were the reasons for low-strength.

Evaluation Of Urban Intersections Using Traffic Conflict Measures, Mike E. Clayton

Kentucky Transportation Center Research Report

The purpose of this report was to analyze two urban intersections using conflict data, erratic maneuver data, and near-miss accident data and to recommend site improvements, if necessary. The two intersections selected were Euclid Avenue at Woodland Avenue and New Circle Road at Woodhill Drive in Lexington. Data were taken using 11-hour observation periods.

Proposed improvements for the site on Euclid Avenue included adding dual left-tum lanes and three-phase signals or an extended multi-turn lane. At the New Circle site, a longer, more gradual right-turn lane and repositioning some of the signing are recommended. The conflict data recorded were found …

Resurfacing, Restoration, And Rehabilitation Of Interstate Highways: Criteria And Logic Used To Determine January 3, 1977, Needs And Estimates Of Costs, Herbert F. Southgate, Donald C. Newberry Jr., Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

This report documents the method, criteria, and/or rules of thumb used for the January 3, 1977, submission to FHWA for "Resurfacing, Restoration, and Rehabilitation" of Kentucky interstate pavements. The period of time covered was 1977 through 1995 and the unit costs used were those for the year 1975.

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

Kentucky Transportation Center Research Report

Statewide survey of skid resistance continued in 1976 with testing of rural, major, collector roads (1985 Functional Classification). This included 5,074 miles (8,166 km) of state secondary roads and 788 miles (1,268 km) of rural secondary roads. About 17 percent of the secondary mileage and about 15 percent of the rural secondary mileage surveyed in 1976 may be considered slippery. A small percentage of both secondary (5.3 percent) and rural secondary (5.8 percent) roads had an average skid number below 26. These sections, in particular, should be flagged for deslicking.

Through 1976, 50 percent of the mileage of rural, state-maintained …

Aasho Road Test Tandem Axleload Data Adapted To Fundamental Concepts, Herbert F. Southgate, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

The reptitions of tandem axleloads applied to the AASHO Road Test were analyzed by the same method previously reported in analyzing the corresponding single axleload data. The essential findings were: 1. One repetition of a 34-kip (151-kN) tandem axleload appears to cause the same damage as one repetition of an 18-kip (80-kN) single axleload. 2. The relationship of log repetitions versus axleload used by Kentucky appear to be equally valid for single and tandem axleloads. 3. The use of superposition principles, and equivalency of repetitions, in combination with terminal serviceability indiced permitted analyses of the tandem axleload data and comparison …

Solar Fluid Heater With Electromagnetic Radiation Trap, Blaine Frank Parker

Biosystems and Agricultural Engineering Faculty Patents

A solar fluid heater including a radiation trap for concentrating solar radiation which has been focused on or near a line at the center of a transparent pipe assembly containing the fluid to be heated is described. The pipe assembly may include one or more transparent pipes containing one or more sets of reflective fins which are disposed in direct heat exchanging contact with the fluid to be heated. The focused radiation entering the pipe assembly experiences multiple reflections off one set of reflective fins therein, thus concentrating the solar radiation. The reflective fins are made absorptive near the apex …

Effectiveness Of Green-Extension Systems At High-Speed Intersections, Charles V. Zegeer

Kentucky Transportation Center Research Report

The purpose of this study was to determine the effectiveness of green-extension systems (GES) for reducing the dilemma-zone problem associated with the amber phase of traffic signals at high-speed intersections. Reactions of 2,100 drivers were noted during the amber phase at nine intersections, and the dilemma-zone distances with respect to the stop bar were determined.

Before-and-after studies made at three green-extension sites showed a 54-percent reduction in total accidents and a 75-percent reduction in rear-end accidents after GES installation. Accident severity was unaffected.

Conflict, volume, delay, and speed data were taken before and after GES installation at two sites. A …

Traffic Accidents: Day Vs. Night, Donald R. Herd, Kenneth R. Agent, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

A comparison of accidents during daylight and darkness was made for both rural and urban roads. Accident rates on all types of rural roads were higher during darkness than during daylight. Critical accident rates during darkness for various types of roads were calculated. In urban areas, a larger percentage of accidents occurred on wet pavements during darkness than during daylight, but there were no significant differences for rural roads. No significant difference was found between average speeds during conditions of daylight and darkness. On rural roads, imposition of the 55-mph (24.6-m/s) speed limit resulted in a reduction in accident rates …

Some Uncertainties Of Slope Stability Analyses, Robert C. Deen, Tommy C. Hopkins, David L. Allen

Kentucky Transportation Center Research Report

Some practical limitations of total stress and effective stress analyses are discussed. For clays having a liquidity index of 0.36 or greater, φ-equal-zero analyses based on laboratory undrained shear strengths give factors of safety close to the actual factor of safety. However, based on field vane strengths, φ-equal-zero analyses may yield factors of safety which may be too high. The difference between field vane and calculated shear strengths increased as the plasticity index increased. For clays having a liquidity index less than 0.36, φ-equal-zero analyses using laboratory undrained shear strengths give factors of safety that are much too high; but …

Acoustic Emission Testing Of High-Strength Steel Weldments, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Manual arc welds were made on high-strength ASTM A 514 and A 588 steels. Different weldment configurations were employed in order to vary the restraint on the welds during cooling. The weldments were monitored 'in-cooling' with acoustic emission equipment. Weldments having greater restraint produced more acoustic emission, usually for longer periods of time. Weldments which fractured during cooling produced more acoustic emission than those which were unflawed.

Computerized Analysis Of Stress-Strain Consolidation Data, E. Gregory Mcnulty

Kentucky Transportation Center Research Report

A computerized, mathematical algorithm is described and presented for analyzing the semilogarithmic stress-strain (time-independent) properties of standard, controlled-gradient, and controlled-rate-of-strain consolidation tests. This algorithm is an automation of manual graphical procedures currently used in engineering practice to obtain stress-strain information necessary for use in time-independent settlement analysis. The Casagrande and Schmertmann constructions are analytically represented to determine the preconsolidation stress and the in situ, compressibility coefficients of compression and expansion. Values for each of these parameters range between a probable and minimum value. The point of maximum curvature is determined for the Casagrande construction by use of the mathematical definition …

Voidless And Internally Sealed Concretes (Construction Report; Silas Creek Bridge, Us 27, Mp-009-0027-B0002), Assaf S. Rahal

Kentucky Transportation Center Research Report

Laboratory investigations on concretes containing super water reducers, PVP and Melment, indicated their suitability for field utilization. Wax beads have been used by other states in concretes for bridge slabs. This report describes the reconstruction of a four-span bridge having three experimental slabs and one conventional slab. Post-construction analyses of cores are included.

Identification Of Hazardous Locations On City Streets, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

The purpose of this study was to develop an effective method for identifying hazardous locations in Kentucky cities (over 2,500 population). Methods used in 45 other states were reviewed. Accident information for 69 of the 97 cities over 2,500 population was used to develop criteria for an identification method.

A Number Method was selected for initial identification of midblocks and intersections on arterial-collector streets and on urban freeways. A Rate-Quality Control Method was included in the form of a critical rate factor computed for each location. A set of critical rate curves was constructed for easy determination of hazardous locations. …

Vertical Drainage In Field Cores, Larry G. Wells, R. W. Skaggs

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.

Transportation Research Reports Issued By The Division Of Research, Robert C. Deen

Kentucky Transportation Center Research Report

A bibliographic listing of research reports issued by the Division of Research, Kentucky Bureau of Highways.

Stiffness Of Solid-Liquid Mixtures: Theoretical Considerations, David L. Allen

Kentucky Transportation Center Research Report

A rational approach to the solution of the stiffness of solid-liquid mixtures is presented. The stiffness of such mixtures is dependent on the stiffness of the viscous medium and the volume concentration and elastic modulus of the solid portion. Finally, the general solution is applied, in particular, to bitumen-aggregate mixtures; and the results are compared to experimental data.

Surface Dynamics Profilometer And Quarter-Car Simulator: Description, Evaluation, And Adaptation, James L. Burchett, Rolands L. Rizenbergs, Thomas A. Moore

Kentucky Transportation Center Research Report

A Surface Dynamics Profilometer was acquired in December 1968. The SD Profilometer was designed to rapidly and accurately measure the profile of the surface over which it is driven. A Quarter-Car Simulator was obtained in 1970. The simulator, a special purpose analog computer, was designed to process road profiles measured with the SD Profilometer. This processing involves analog simulation of a simplified vehicle. Factors and variables associated with the devices and calibration and test procedures were investigated and standardized. The Automatic Roughness-Measuring System using an automobile (Kentucky interim standard method of test for roughness) was correlated with the SD Profllometer …

Modeling Soil Water Movement Into Plant Roots, D. C. Slack, C. T. Haan, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

Mathematical model was developed which describes uptake of water by plant roots as a function of leaf and soil water potentials. The model was used to estimate transpiration from corn grown in a controlled environment under soil drying conditions. The model predicted daily transpiration quite well for the period modeled.

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 …

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 …

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 …

Renovating Grass Fields With A Renovation Seeder, Edward M. Smith, Robert L. Fehr, Garry D. Lacefield, J. Kenneth Evans

Agriculture and Natural Resources Publications

Putting legumes into grass dominant pasture and hay fields through renovation is certainly not a new idea in Kentucky. Renovation has been an important forage improvement practice for the past twenty years. What is relatively new is the power tillage technique of introducing legumes into grass dominant sods.

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.

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 …

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 …

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.