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SWUTC Ph.D. Candidate Assistantship Project Description

Development of a Performance-Related Specifications Methodology for Pavement Preservation Treatments

University: Texas A&M University

Principal Investigator:
Litao Liu
Zachry Department of Civil Engineering
(979) 845-9914

Faculty Supervisor:
Nasir Gharaibeh
Zachry Department of Civil Engineering
(979) 845-3362

Funding Source: USDOT Funds

Total Project Cost: $32,079

Project Number: 600451-00020

Date Started: 9/1/12

Estimated Completion Date: 8/31/13

Project Summary

Project Abstract:
Current materials and construction specifications used by highway agencies provide little or no linkage between initial quality of preservation treatments and their future performance (short and long-term). As a result, highway agencies have very limited or no capacity to capture the performance lost or gained due to differences between the as-designed product and as-constructed product; on the other hand, contractors’ ability to innovate on quality characteristics that affect the treatment’s in-service performance is also limited by this. Performance-related specifications (PRS) that specify quality in terms of parameters that correlate with future performance provide an alternative approach to address these limitations. Over the past decades, significant progress has been made in developing and implementing PRS for new pavements. However, the transportation community is lacking PRS methodology and guidelines for pavement preservation treatments.

Project Objectives:
The objective of this research is to develop a PRS methodology for two commonly used HMA pavement preservation treatments: thin overlay (0.5 in. to 2 in. in thickness) and chip seal. To accomplish this objective, the following issues will be addressed:

  • Identify acceptance quality characteristics (AQCs) that correlate with performance or longevity of the pavement. These AQCs should be measurable and can be controlled by the material supplier and/or contractor.
  • Develop models for predicting the treatment performance and longevity as a function of initial quality (as measured by the AQCs), condition of the existing pavement, and site conditions (climate, traffic loading, etc.).
  • Develop a method for determining pay adjustment factors based on performance lost or gained due to differences between the as-designed (i.e., target) and as-constructed level of quality.
  • Integrate the AQCs, performance/longevity prediction models, and pay adjustment method into a coherent methodology for developing PRS for pavement preservation treatments (specifically, thin overlays and chip seals).

Task Descriptions:

Task 1. Review literature and current practices of pavement preservation.

Task 2. Identify preservation treatments for consideration in the PRS methodology.

Task 3. Extract necessary data from the LTPP database.

Task 4. Develop performance prediction models for pavement preservation treatments.

Task 5.  Integrate the development performance prediction models into a PRS methodology for pavement preservation treatments.

Task 6.  Test and evaluate the developed PRS methodology.