PAVEMENT TESTING SERVICES

From advising airports on the ability of their pavement facilities to handle additional aircraft traffic to assessing roadway pavement failures, APTech has successfully provided evaluation and testing services to highway and airport agencies throughout the United States and beyond. The following highlights some of our project examples.

Macon County, Illinois, Roadway Testing, Evaluation and Design

APTech conducted an evaluation of a number of roadways in Macon County near Decatur, Illinois. The evaluation included a visual examination of pavement condition, dynamic cone penetrometer (DCP) testing to evaluate support conditions, and falling weight deflectometer (FWD) testing to evaluate the pavement's load carrying capability. Overall, the purpose of this investigation was to develop pavement overlay designs for these roadways in order to provide a pavement that was structurally adequate to handle the projected traffic loadings over the next 20 years.

Prior to the development of new overlay designs, the DCP testing results, which where correlated to CBR values, and the FWD results were used to conduct a remaining life analysis. The FWD results are also used as inputs in the AASHTO and Asphalt Institute design procedures to evaluate the structural capacity of the pavements. Overlay designs were also generated from this analysis. Recommendations for additional repairs prior to overlay placement were also developed based upon the visual condition assessment. A final site investigation was conducted to acquire work quantities in order to estimate the cost of these improvements.

APTech's engineers were responsive to the client's need for immediate results, and completed the project in just a few days.

Pavement Testing and Needs Assessment for Tulare County Road 80

APTech conducted a pavement evaluation and structural needs assessment for 14 miles of County Road 80 in Tulare County, California, between the cities of Visalia and Dinuba. County Road 80 represents a major thoroughfare in the Central Valley and was targeted for both structural improvements and widening to accommodate the projected future traffic.

The pavement evaluation for this project consisted of nondestructive testing using a falling weight deflectometer, a condition survey, and a program of field sampling and laboratory testing. The structural needs assessment consisted of a structural capacity analysis of the existing pavement and the determination of HMA overlay thickness designs for the existing pavement as well as HMA pavement structural designs for the areas to be widened from two lanes to four. The evaluation and needs assessment were carried out using the design procedures presented in the current AASHTO Guide for Design of Pavement Structures. A comprehensive report documenting the project findings (i.e., structural capacity and distress survey results) and structural design recommendations was prepared and submitted to the client.

Pavement Testing and Needs Assessment for Craig Road, City of Las Vegas

APTech conducted a thorough pavement evaluation and structural needs assessment on roughly 1.8 miles of Craig Road in the City of North Las Vegas, between Commerce Road and Berg Street. Craig Road is a major arterial and in the northern part of the city and, because of high traffic and poor current condition, required major structural improvements and pavement widening.

A thorough pavement evaluation consisting of nondestructive testing using a falling weight deflectometer (FWD), an intense pavement condition (distress) survey, and limited field sampling and laboratory testing was conducted. The structural needs assessment consisted of a pavement capacity analysis of the existing HMA pavement and the development of both HMA and PCC pavement reconstruction designs.

The structural evaluation and surface thickness designs were carried out using the design procedures presented in the current (1993) AASHTO Guide for Design of Pavement Structures (AASHTO Guide.) Based on an analysis of the results, it was recommended that the existing pavement be reconstructed and widened using a 230-mm (9-in) HMA surface. This constituted a 15-year pavement design the would require two HMA overlays at years 15 and 25 to achieve the targeted 35-year design life.

Westchester County Airport Taxiway Testing, Evaluation and Design

APTech teamed with Clough, Harbour & Associates (CHA) to conduct a pavement evaluation and provide rehabilitation recommendations for Taxiway A, the parallel taxiway to the primary runway, and its associated connecting taxiways. The evaluation included a thorough records review, a condition survey of the entire pavement area, nondestructive testing using APTech's heavy-weight model falling weight deflectometer, and extensive pavement coring and boring. The available information was analyzed and recommendations were developed for each pavement section. The extensive deterioration and high deflections, coupled with the poor subgrade support conditions and grade constraints, made an HMA overlay an unsuitable solution. Reconstruction was deemed to be the most cost-effective alternative, and both HMA and PCC pavement designs were developed.

John Degerman Field (Wisconsin) Evaluation of Pavement Capacity

APTech was employed by HNTB Corporation to evaluate the pavement facilities at John Degerman Field near Solon Springs, Wisconsin. Specifically, the airport wanted to investigate the ability of the runway and apron pavements to handle additional aircraft that the airport was hoping to add to its current traffic mix.

Nondestructive testing using APTech's falling weight deflectometer (FWD), pavement coring, and soil boring and testing were conducted to determine the cross section and properties of the pavement structures. An evaluation of the structural capacity was performed using the FAA design methodology as well as a mechanistic-empirical analysis. The results suggested that the pavements were currently not structurally adequate to handle the proposed aircraft, although further analysis indicated that only a minimal overlay was needed.