U.S. Department of Transportation
Federal Highway Administration
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Washington, DC 20590
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
|This report is an archived publication and may contain dated technical, contact, and link information|
Publication Number: FHWA-RD-02-088
Date: May 2003
The load transfer efficiency (LTE) of cracks and joints profoundly affects the performance of concrete pavements. Poor LTE may lead to longitudinal cracking and excessive faulting of jointed concrete pavements (JCP) and could accelerate punchout development in continuously reinforced concrete pavements (CRCP). These distresses could lead to roughness and poor ride quality. Conversely, joints and tightly closed transverse cracks with high LTE do not typically cause any pavement serviceability problems.
As part of the ongoing Long-Term Pavement Performance (LTPP) program, deflection measurements are being taken with the falling weight deflectometer (FWD) on all general pavement studies (GPS) and specific pavement studies (SPS) test sections. This deflection testing program is being conducted periodically to obtain the load-response characteristics of the pavement structures at critical points in time, depending on the experiment. These data are intended to provide pavement structural characteristic data that are needed to achieve the goals of LTPP program. Many State highway agencies also are collecting deflection data on their pavement systems for management, project rehabilitation, and forensic studies, and they consider deflection data to be as important as pavement condition and distress data.
Deflections, temperature, and joint opening size are all measured at joints/cracks. The data collected include the following:
The primary objectives of this study are to compute:
The computed parameters will then become a part of the LTPP database for use in future studies.
Secondary objectives of this proposed study are as follows:
The scope of this LTE analysis study for LTPP rigid pavement sections includes the following:
This report documents the research effort and findings of the LTPP rigid pavement joint parameters such as LTE, stiffness, and variation in opening. This chapter presents background information. Chapter 2 provides details on the selection of the methodology for calculation of LTE and stiffness of joints and cracks. Chapter 3 presents the results of the assessment of FWD deflection data used in joint LTE calculation and describes the procedure used to determine representative LTE parameters. Chapter 4 presents results of the analysis for GPS and SPS test sections. Chapter 5 presents results of the LTE analysis for SMP test sections. Chapter 6 presents the methodology and results of the analysis of joint stiffnesses. Chapter 7 presents the methodology and results of the analysis of changes in joint opening. A summary and list of recommendations are presented in chapter 8.