Master of Science / Department of Civil Engineering / Mustaque A. Hossain / Road surfaces may prematurely lose pavement friction due to polished aggregates on sharp horizontal curves, steep grades, or near intersections resulting in vehicle skidding. The problem gets exacerbated during wet weather. The Federal Highway Administration (FHWA) estimates that about 70% of wet pavement crashes can be prevented or minimized by improving pavement friction. High Friction Surface Treatment (HFST), a specially-designed thin surface application of hard aggregates and thermosetting resins like epoxy, has been proven to be an effective method to increase road surface friction. Calcined bauxite has been predominantly used in the United States as the hard aggregate in combination with an epoxy binder for HFST. However, this treatment is expensive since the calcined bauxite is imported. The objective of this study is to evaluate the performance of a local aggregate in HFST. Slab specimens of hot-mix asphalt (HMA) were compacted in the laboratory and treated with HFST systems incorporating both calcined bauxite and a local, hard aggregate, Picher Oklahoma flint aggregate. The treated HMA specimens were then tested with a Dynamic Friction Tester (DFT) and a Circular Track Meter (CTM) to determine the frictional coefficient and texture depth, respectively. Also, Hamburg Wheel Tracking Device Testing were conducted on these HFST systems to evaluate wearing resistance under repetitive wheel load. Field measurements of texture depths on HFST were also done. Statistical analysis was performed to compare the performance of high friction surfaces prepared with different aggregate epoxy combinations. The results show that flint aggregate can be a suitable substitute for the calcined bauxite in HFST. Field measurements also showed marked improvements in texture depth with HFST.

State highway agencies have an obligation to provide users with optimal surface conditions under various weather conditions throughout the year. A satisfactory pavement surface should exhibit good friction and texture depth to reduce roadway highway accidents. This is why friction is starting to receive increased attention in the pavement management process. There have been numerous research efforts by different countries and agencies to better understand the behavior of different friction testing devices and the influence of texture, speed, and other external conditions on their measurements. The first part of this thesis presents a research effort to compare and harmonize texture and skid resistance measurements taken with various devices on 24 pavement sections with a wide range of textures. Measurements were compared and the International Friction Index (IFI) calculated following PIARC and ASTM steps. The results revealed discrepancies in the IFI values calculated for the different devices, suggesting that the coefficients A, B, and C proposed by PIARC may need to be adjusted for each device considered before the IFI can be implemented by the surface properties consortium participating agencies. In this research the A, B, and C coefficients were then recalculated, and the predicted values of friction using these revised coefficients are presented. The coefficients developed were also used to obtain IFI values for high-friction surfaces (HFS). It has been found that under different conditions, different parameters and coefficients will result. It is strongly recommended equipment comparison experiments (like the NASA and Smart Road programs) continue to better determine the coefficients necessary for harmonization. HFS have emerged as viable high-friction pavement alternatives that mitigate the consequences of driver error, poor geometric alignment of the roadway, and insufficient friction at the tire-pavement interaction, especially during wet weather. This thesis presents a study of the HFS available in the U.S. market and their performance (friction and texture) in different applications, under different weather conditions, and in various locations. This thesis also presents the results of the benefit-cost analysis for the studied HFS. / Master of Science