RESEARCH ACTIVITIES

APTech is respected for its history of leadership in prominent pavement research programs, having played an instrumental role in large-scale, national pavement research projects as well as small studies for states and municipalities. The following highlights some of our project examples.

Technical Support for FHWA's Concrete Pavement Technology Program (CPTP)

The Concrete Pavement Technology Program (CPTP) is a national program of research, development, and technology transfer that operates within the Federal Highway Administration (FHWA). Launched in 1998 under TEA-21 legislation, the goal of the program is on implementing improved methods of designing, constructing, evaluating, and rehabilitating portland cement concrete (PCC) pavements in order to promote cost-effective designs and long-term performance for federal-aid highways. Six focus areas have been established under the CPTP relating to various aspects of concrete pavements: advanced pavement design, improved concrete materials, improved construction processes, rapid repair and rehabilitation, enhanced user satisfaction, and trained workforce.

Under the FHWA's Technical Support contract, APTech is serving as a subcontractor to Construction Technology Laboratories, Inc. (CTL). The objective of this project is to provide both the engineering and marketing support services needed for the timely and cost-effective technology transfer, deployment, and delivery of products resulting from research and development projects in the CPTP. Work to be performed under this contract will be based upon products resulting from the CPTP and the related marketing strategies that are proposed by FHWA. The principal recipients of the products resulting from the CPTP are FHWA's customers and partners, including State highway agencies (SHAs), industry groups, research and standard-setting organizations, and academia.

New Pavement Design Guide Implementation Plan for South Dakota (SD2005-01)

The State of South Dakota is working to become familiar with the implementation requirements associated with the new Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under National Cooperative Highway Research Program (NCHRP) project 1-40. Because the new M-E design process depends on a large number of inputs related to structural design, materials selection, and construction-related parameters, a well-organized implementation plan is necessary to customize the design process. To that end, South Dakota has contracted with APTech to address these issues and to achieve the overall objective to develop an implementation plan for adopting the new MEPDG. This customized plan will enable South Dakota to produce more effective and reliable pavement designs, to extend pavement service life, and to make more cost effective investment decisions. Specifically, APTech is summarizing the inputs and associated resources required to implement the M-E design guide, conducting a cost/benefit and sensitivity analysis on the design inputs and comparing those results with current design standard inputs, and developing recommendations for input defaults and data needs to calibrate coefficients to reflect local conditions

Guide for Optimal Timing of Pavement Preventive Maintenance Treatment Applications

APTech conducted a two-phase study on the optimal timing of preventive maintenance for the National Cooperative Highway Research Program (NCHRP 14-14). The original objective of this research was to develop a Guide for determining the optimal timing for the application of preventive maintenance treatments on HMA- and PCC-surfaced pavements. However, because of the limited amount of data available to support an analysis of preventive maintenance performance at various application timings, the focus of the second phase of the project was modified. Instead of developing guidelines for treatment timing, APTech developed a methodology that could be used by state highway agencies to determine the optimal time to apply preventive maintenance and developed a spreadsheet-based analytical tool to apply the methodology to actual or estimated performance data. The methodology was validated using data provided by the Kansas, California, Michigan and Nevada DOTs.

Innovative Pavement Research Foundation Task 6-Incremental Costs and Performance Benefits of Various Features of Concrete Pavements

The construction of a concrete pavement involves decisions between design features and their associated costs. To assist transportation agencies with the evaluation of these trade-offs, APTech was selected to conduct this research for the Innovative Pavement Research Foundation (IPRF). The objective of this research was to document the performance benefits associated with various concrete pavement design features, while also establishing the construction costs associated with each design feature. A major part of this project involved the development of a user-friendly computer software package that allows pavement designers to compare the impact of design features on cost and performance of concrete pavements. This tool allows agencies to better optimize their concrete pavement designs so they can provide more value to the traveling public and possibly construct, or reconstruct, more miles each year with the same level of funding.

Status of High Performance Concrete Pavements

APTech was selected by FHWA to evaluate the status of the test and evaluation projects funded under its Test and Evaluation Project 30 (TE-30) titled "High Performance Concrete Pavement (HPCP)". The status of each of the 17 projects from 11 states was documented to provide insight into the effects of a broad range of innovative concrete design features and construction concepts. The results were summarized in a report that also outlined the outcomes that can be anticipated from the construction of experimental pavements and how those results may be used by the highway community.

Concrete Overlays: State of the Technology Report

APTech prepared a state-of-the-technology report on concrete overlays under this FHWA project. This report compiled the most recent information and guidance on the design, construction, and performance of four concrete overlay types: bonded, unbonded, ultra-thin whitetopping, and conventional whitetopping. After successful balloting among ACI members, the report was incorporated into its Manual of Practice. In addition, six technology briefs were prepared as a means of disseminating key technical information on a specific overlay topic. Finally, a workshop was developed and conducted in selected sites around the country to help promulgate information on the design, construction, and applicability of concrete overlays.