ROADWAY EVALUATION AND DESIGN PROJECTS

Pavement Testing in Sangamon County, IL

APTech was contracted by American Engineering Testing, Inc. (St. Paul, Minnesota) to conduct FWD testing and a cursory condition survey on 4.6 centerline miles of recycled asphalt roadway in Sangamon County. While at the location, APTech conducted FWD testing and coring on an additional 6 centerline miles of asphalt roadway directly for the Sangamon County Highway Department. All collected FWD data was delivered to American Engineering Testing, Inc. for analysis, while the cores were delivered directly to the County.

Pavement Evaluation and Structural Needs Assessment of Rohnert Park Expressway

APTech conducted a pavement evaluation and structural needs assessment on the Rohnert Park Expressway (RPE) and five high-volume streets within the City of Rohnert Park, California. The pavement evaluation for this project consisted of pavement condition surveys, nondestructive testing (NDT) using a falling weight deflectometer (FWD), and limited field sampling and laboratory testing. The structural evaluation consisted of a structural capacity analysis of the existing pavement based on the pavement evaluation data. Both the evaluation and rehabilitation design were carried out using the design procedures presented in Caltrans' Flexible Pavement Rehabilitation Manual (June 2001) and the test procedures detailed in California Test 356, Methods of Test to Obtain Flexible Pavement Deflection Measurements for Determining Pavement Rehabilitation Requirements (June 2004).

Detailed condition surveys, FWD testing, materials sampling, and limited laboratory testing were performed on representative pavement sections within the RPE and the individual city streets. Based on these evaluations and initial construction cost analyses, APTech developed rehabilitation/reconstruction design alternatives and final design recommendations. One of the unique recommendations was the use of a gap-graded rubberized asphalt concrete (RAC-G) mixture for structural rehabilitation. The use of RAC-G mixtures has become very common within Caltrans, but not yet within local agencies, including Rohnert Park. The significant cost savings associated with the reduced remove and replace requirements of RAC-G over conventional dense-graded hot-mix asphalt made the use of RAC-G the first choice by City staff.

Evaluation and Rehabilitation Recommendations for Wright and Fifth Streets in Champaign, IL

The City of Champaign contracted with APTech to conduct an evaluation of portions of two city streets: Wright Street and Fifth Street. These pavements were exhibiting significant deterioration and were programmed for rehabilitation. However, certain characteristics associated with each street raised some concerns regarding the development of appropriate rehabilitation treatments. In addition, both facilities have an existing curb and gutter, so the curb reveal and storm drainage capacities had to be maintained.

APTech conducted detailed evaluations of these pavements, with follow-up testing and evaluations shortly thereafter. The objective of the field testing was to fully characterize the existing pavement condition so that appropriate rehabilitation recommendations could be developed. The field testing consisted of a pavement distress survey, pavement coring, dynamic cone penetrometer (DCP) testing, and falling weight deflectometer (FWD) testing. Upon completion of the field testing, APTech analyzed the results and developed recommended rehabilitation designs.

Deflection Testing and Structural Pavement Design Services for the City of Sacramento

APTech carried out this project under its on-call pavement testing/design agreement with the City of Sacramento Department of Public Works. The City requested overlay thickness design recommendations for three separate streets: Del Paso Blvd (north of Arco Arena), 5th Street (near downtown), and Meadowview Road (south of downtown). APTech carried out the field evaluation and design work according to the protocol and design criteria presented in the Caltrans Flexible Pavement Rehabilitation Manual.

The field evaluation consisted of condition surveys, nondestructive testing (using the APTech falling weight deflectometer), and limited field sampling and lab testing. The rehabilitation design for all three streets called for patching, some partial depth removal of the existing HMA surface (via a cold milling operation) and the placement of an HMA overlay. Because of its cost effectiveness and local availability, a rubberized asphalt concrete (RAC) mixture was recommended for most if not all of the overlay.