This technical memorandum describes work undertaken to establish an appropriate temperature correction equation for the British Pendulum Tester (BPT). The recommended correction equation was based on data collected in typical summer conditions in California and on previously constructed bituminous surfacings. The effects of different operators, instruments, levels of slider pad wear, and temperature were also studied in another experiment. No appreciable differences were found to be caused by the variables as long as the correct procedures were followed, the devices calibrated, and the surface temperature of the test pavement accounted for.

This memorandum reviews the different devices used to measure pavement surface friction, and the correlation between friction results measured using California Skid Tester (CST), the British Pendulum Tester (BPT), and other devices. It also reviews the methods used to calibrate friction results measured at different pavement temperatures, and the performance of fog seals, including the friction on fog seals.

This technical memorandum describes an investigation (1) to measure the change in pavement surface friction at three hours and at three days after application of six rejuvenators as fog seals and (2) to compare friction values obtained using the California Skid Tester (CST), the British Pendulum Tester (BPT), and the Dynamic Friction Tester (DFT). Statistical correlations among the CST, BPN, and DFT are presented.

This report summarizes a detailed report presenting the first and second year of field and laboratory measurements and statistical analyses and performance estimates for tire/pavement noise, permeability, ride quality, distress development, and friction properties of four types of asphalt pavement surface types used by the California Department of Transportation: open-graded asphalt concrete (OGAC), rubberized open-graded asphalt concrete (RAC-O), rubberized gap-graded asphalt concrete (RAC-G) and dense-graded asphalt concrete (DGAC). Tire/pavement noise was measured using the on-board sound intensity method (OBSI). A factorial experiment was developed and executed that considered these surface types, rainfall, traffic and age, with sections selected in the following age groups: less than one year old, one to four years old, and four to eight years old. A partial factorial was included for another type of open-graded mix, called F-mix. In addition, special sections placed by various Caltrans pilot and research projects were also included in the plan for field monitoring and laboratory testing. The report summarizes the measured performance and presents summary statistics for the results. Statistical analyses were performed, including single-variate regression to identify significant variables, multivariate regression, survival analysis, and principal components regression, depending on the type of data, in order to estimate performance. The performance models were used to estimate the life of the various surface types for the conditions in the experiment. The median noise reduction across the population included in the experiment is approximately 2 dB(A) for OGAC and approximately 3 dB(A) for RAC-O mixes compared to the DGAC mixes for the Standard Reference Test Tire (SRTT), with values converted from the Aquatred tire measurements used in the project. The Aquatred results are slightly different prior to conversion to the SRTT values, indicating slightly less noise benefit from open-graded mixes and less difference between OGAC and RAC-O.

This technical memorandum presents the results of pavement evaluation and rehabilitation design for 01-LAK-53, PM 3.1/7.0. The pavement evaluation consisted of deflection testing, coring, and material sampling; backcalculation of stiffnesses using the CalBack program; and condition assessment. Designs were prepared using current Caltrans methods, and alternative rehabilitation designs were prepared using mechanistic-empirical software and models included in the CalME program.

This technical memorandum presents the results of pavement evaluation and rehabilitation design of 02-PLU-36, PM 6.3/13.9. The pavement evaluation consists of deflection testing, coring, material sampling, backcalculation of stiffnesses, and condition assessment. Rehabilitation designs were developed using standard Caltrans methods. Alternative rehabilitation designs were developed using mechanistic-empirical software and models (CalME). Performance of all designs was assessed using mechanistic-empirical models. Suitable designs are recommended.

The central purpose of the research is to support the California Department of Transportation (Caltrans) Quieter Pavement Research Program, which has as its goals and objectives the identification of quieter, safer asphalt pavement surfaces. The research conforms with Federal Highway Administration (FHWA) guidance provided to state departments of transportation (DOTs) that conduct tire/pavement noise research. Results from this research are intended to identify best practices for selecting asphaltic surfaces based on performance trends identified from field measurements for noise, permeability, friction, and durability. This report evaluates the first two years of measurements of noise (on-board sound intensity), permeability, skid resistance (friction), roughness, and surface distresses of the most common asphalt pavement surface types in California: open-graded asphalt concrete, which includes conventional mixes (OGAC), rubberized mixes (RAC-O), and F-mixes; rubberized gap-graded asphalt concrete (RAC-G); and dense-graded asphalt concrete (DGAC). The sample of pavement surfaces in this study includes three age categories, two traffic types, and two rainfall regions. This report presents results for the sections in the factorial experiment in the detailed Work Plan for this project. This report also presents similar results for the Division of Environmental Analysis sections and other special test sections, which are referred to as ES sections. This report presents all results for the factorial sections and ES sections, some of which were presented in previous interim reports. Conclusions are made regarding the performance of open-graded mixes and RAC-G compared with DGAC; the variables affecting tire/pavement noise; the correlation of laboratory absorption values with field-measured noise levels; and the performance of mix types included in the study in addition to DGAC, OGAC, RAC-O, and RAC-G. Preliminary recommendations are made for practice based on the results, and recommendations are made for future work.