Visual Observations of Parking and Driving Areas and Drainage Conditions on Colverfield Lane Fort Wright Trace, Fort Wright, KY.

On September 30, 1993, the Condominium Council of Co-Owners of Fort Wright Trace in Fort Wright, Kentucky requested of the Director of the Kentucky Transportation Center that a member of his staff meet with them to review and visually inspect the drainage and pavement conditions in their community. The Head of the Pavements Section met with representatives of the Council on October 13, 1993 as a part of the Transportation Center\u27s Technology Exchange Program. A visual inspection was conducted of Cloverfield Lane and its associated parking areas beginning at the intersection of Cloverfield Lane and Castle Hill Lane and continuing to the end of Cloverfield Lane. It should be noted that all statements, conclusions, and recommendations that follow in this report are based strictly upon the visual inspection. No field measurements were made, nor were any laboratory tests conducted

Rheological Response of Asphalts

The rheological response of asphalt cements to shearing stresses is presented. The behavioral characteristics were measured using a rotating coaxial cylinder viscometer. Little or no development of theory is presented. The viscoelastic portion of deformation is discussed in terms of the creep function. Plastic deformation is described using the definitions of apparent and plastic viscosities. Curves showing the effects of temperature, stress level and penetration on these two major components of strain are presented and discussed. Analysis indicated that plastic deformation is the predominant component of strain and, thus, should be considered and incorporated in the design of flexible pavements

The Creep Response of Cohesive Soils: A Method of Design Using Rheological Strength Parameters

The creep response of four remolded soils and undisturbed soils from two landslide sites is presented. A method for obtaining the yield stress of soil from creep test data is presented and discussed. Viscosity diagrams , showing the location of the yield stress is approximately 50 percent of peak stress, were obtained from conventional triaxial tests. There is more scatter in data from undisturbed soils than in data from remolded soils. Mohr\u27s failure envelopes, constructed from yield stress data, give internal friction angles having values from approximately five to ten degrees. Strength data, calculated indirectly from peak relaxation modulus, are also presented. Stability analyses are presented on two selected landslides. Analyses are made and compared using peak, Residual , and yield stresses. Results indicate yield stress should be considered when designing earth structures

Stiffness of Solid-Liquid Mixtures: Theoretical Considerations

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

Review and Analysis of Pavement Management Practices in Kentucky

Pavement Management is becoming increasingly more important in an era of limited budgets and aging pavement structures, State Highway Agencies (SHA) are attempting to manage the pavements under their jurisdiction more carefully and economically. All pavement management systems include all or some of the following items as inputs: (1) pavement distress, (2) serviceability or rideability, (3) inventory of the system, (4) structural adequacy, (5) traffic volumes and loadings, and (6) some form of performance history. This report documents Kentucky\u27s present pavement management system. In addition, the duties and goals of the Pavement Management Branch are catalogged and described. Methods for rating pavements are described. The allocation of funds and how this allocation is calculated are described. Methods of determining estimates for rehabilitation needs are also described. A description of the organization and flow of information in the PMS is given in detail. Comparisons are made between Kentucky\u27s PMS and the elements of a pavement management system to be required by the Federal Highway Administration in 1993. Kentucky\u27s PMS is well advanced and most of the elements in the Federal Guidelines are already in place or are in some stage of development. Life-cycle costs analysis procedures need to be developed and adopted. Greater use of the present data bases is encouraged

Comparison of Three Methods of Pavement Design for Lexington-Fayette County

It is imperative in an era of limited budgets for construction and maintenance of streets and highways that a rational approach be followed for managing these funds. One of the first steps of this management process is the adequate and proper design of new streets and roads. In the interest of having a more rational system of design, representatives of the Lexington-Fayette Urban County Government requested the Kentucky Transportation Center to assist in the development of a new pavement design system that more clearly reflects differences in soils, traffic streams, environmental conditions, and materials. In fulfillment of that request, this. brief report compares three available methods of pavement design for flexible pavement and one method of design for rigid pavement. Comments and recommendations based upon pavement design experience and field performance of pavements are also included

Analysis of Edge Drains on Western Kentucky Parkway Milepost 83 to Milepost 90

On August 14. 1989. the Kentucky Transportation Cabinet requested the Kentucky Transportation Center (KTC) to investigate an apparent drainage problem on the Western Kentucky Parkway. The area of concern was a rehabilitation project starting at Milepost 83 and ending at Milepost 90. The old PCC pavement was being broken and seated and was being overlayed with approximately five inches of asphaltic concrete. Longitudinal edge drains (Hydraway brand) were installed in 1988, but the PCC pavement was not broken until July, 1989. Two inches of asphaltic concrete base were placed over the old broken pavement, and were used as a driving surface for a short period. During that time, several heavy rains occurred. After the rains, it was evident that a large amount of silt had been pumped up through the two inches of new base and deposited on the shoulder. The source of water and the silt was not immediately evident. Field inspection and laboratory permeability tests indicated the drains were performing, but on several occasions, more water was seeping through the new asphalt overlay and the old broken slab than the drains had capacity to carry. This was causing water to backup in the drains and flow upwards through the new overlay and exit onto the shoulder. It is recommended that the outlet headwalls be spaced no farther than 450 apart on two percent grades or greater, and 200 to 250 feet apart on grades less than two percent. It is also recommended that riding surface be a Class I or a Class A surface mixture. This will reduce the amount of water that seeps into the pavement

Determination of Rutting in Asphaltic Concrete Pavements: Field Instrumentation and Laboratory Characterizations

This report describes a number of gages developed to measure the location and magnitude of ruts. These were installed in a newly constructed asphaltic concrete pavement. They measure lateral deflections and transient and permanent vertical deflections. Some preliminary vertical deflections are reported. An investigation of materials is also reported. The asphalt concrete base, dense-graded aggregate base, and subgrade material were characterized by (1) shear strength (triaxial tests), (2) rheologic behavior (creep tests), (3) permanent deformation characteristics (repeated-load and creep tests), (4) Young\u27s modulus (resonant column tests), and (5) resilient properties (repeated-load tests). Empirical functions were formulated to describe the permanent deformation characteristics of all three materials

A Computerized Analysis of Flexible Pavement Rutting Behavior (PAVRUT)

Flexible pavements are known to fail in several modes, one of which is rutting. In an effort to determine where in the pavement structure and to what extent rutting occurs and to determine the factors that control rutting, a comprehensive laboratory testing program was performed. Various traffic and environmental parameters were controlled in the study; and from the data, mathematical models that describe the rutting characteristics of an asphalt concrete, a dense graded aggregate, and a subgrade soil were formulated. Details of the materials, equipment, and laboratory procedures were reported by Allen in a previous report. Also, the mathematical models were described in that report and are listed again in this report for convenience. A traffic and a temperature model were also formulated to provide necessary input into the rutting models. These are described in this report. These models have been programmed and collected into a large computer program entitled PAVRUT. Using this program, an estimated rut depth can be calculated for any flexible pavement, assuming the volume and characteristics of the traffic stream are known