Field performance monitoring and modeling of instrumented pavement on I-35 in McClain county - phase I

Flexible pavements comprise about 93 percent of paved roads in the United States. Although flexible pavements are widely used for reasons such as cost, constructability and consistent performance, they are often subject to severe cracking and rutting. This combined laboratory and field study is conducted to better understand the mechanisms that cause pavement failure under actual traffic loading and environmental conditions. A 1,000-ft. long experimental pavement section was constructed on I-35 in McClain County and instrumented in collaboration with the National Center for Asphalt Technology (NCAT) and the Oklahoma Department of Transportation (ODOT) for field data collection. The test section was designed to fail in a relatively short amount of time under heavy interstate traffic. The field data collection focused on pavement response data (longitudinal and transverse strains at the bottom of the asphalt layer, Falling Weight Deflectometer testing), environmental data (temperature within the pavement), performance data (rut and cracks on the surface of the pavement) and actual traffic data (number of trucks, axles, and axle load). From the field data, fatigue and rut prediction models were developed. A separate statistical rut prediction model was also developed from the laboratory rut tests using the Asphalt Pavement Analyzer (APA). Additionally, from the laboratory four-point fatigue tests data, fatigue cracking susceptibility towards temperature was analyzed.Final Report October 2006 - December 2012N

EVALUATION OF THE ENHANCED INTEGRATED CLIMATIC MODEL FOR SPECIFICATION OF SUBGRADE SOILS IN OKLAHOMA

The main objective of this study was to collect and evaluate climatic and soil data pertaining to Oklahoma for the climatic model (EICM) in the mechanistic-empirical design guide for pavements. The EICM climatic input files were updated and extended over a large area covering Oklahoma climatic conditions. Large cluster of raw climate and soil moisture data were obtained from the Oklahoma Mesonet for evaluation and use in creating the necessary input parameters for the climatic model. Historical climatic data were also employed for classifying climatic regions in Oklahoma using cluster analysis. Thornthwaite Moisture Index (TMI) contour maps were created using the climatic data and ArcGIS software. A comprehensive validation study was also undertaken in comparing the moisture migration processes in the EICM and commercially available software using the climatic and soil data in Oklahoma.Final report, October 2011-December 2013N

Overturning Forces at Bridge Abutments and the Interaction of Horizontal Forces from Adjacent Roadways (FHWA-OK-17-03)

ODOT is experiencing a number of problems related to the interactions between bridge abutments and adjacent roadways. These problems include expansion joints closing, roller support bearings tilting, and beams pushing against abutment backwalls. Design, construction, repair, and maintenance guidelines to alleviate adverse effects of interactions between ODOT bridge abutments (non-integral), bridge decks, and adjacent roadways are developed based on field observations, instrumentation of selected bridges, and computer simulations. Three bridges were selected for detailed instrumentation including measurements of strains at various locations of approach slabs, approach pavements, and bridge decks; relative displacements between approach slabs and approach pavements; relative tilt of the abutment backwalls and pier caps; and temperatures at various locations over a period of seven years. At two of these bridges, measurements were also made before and after repairs. In addition, strains near newly installed expansion joints on five other bridges were monitored. The observed distresses were classified into two main categories. One related to rigid approach pavements exerting pressures on the bridges and the other related to lateral displacements from tall approach embankments early in the life of the bridges. A 4-inch pressure relief joint installed on an approach pavement was found to relieve bridge stresses caused by a rigid approach pavement. Providing expansion joints on rigid approach pavements at regular intervals, maintaining expansion joints on bridges and pavements, and geotechnical analyses to calculate lateral displacements from tall approach embankments during the design phase are some of the recommendations made to prevent or remediate the observed distresses.October 2010-September 2017N