Dragging a broom or an inverted piece of AstroTurf in the longitudinal direction currently textures concrete pavements built in Minnesota. The macro-texture is specified to have a mean texture depth of 1 millimeter measured by the Sand Volumetric Technique (ASTM E 965). Newly textured pavements are usually evaluated for adequacy in providing a safe riding surface through texture measurements for acceptance and friction measurements as required. The current Federal Highway Administration (FHWA)'s Technical Advisory on texture requires that performance of non-convention textures be monitored and reported. This report presents the Minnesota Department of Transportation's study of AstroTurf texturing practices and pavement friction. The friction numbers are collected using the ASTM E 274 standard and the values from the Minnesota Road Research Project (MnROAD) were used to create a time and loading dependent model. Friction numbers from various test sections around the state of Minnesota and the model created from the MnROAD facility were then compared using visual analysis, descriptive statistics, Chi-Squared Analysis and the Mann-Whitney Z Test. After the completion of those tests, it was concluded that the three models created from the MnROAD facility were validated from the test sections created around the road network in Minnesota.
A study examined thirty one pavement test sections in the Minneapolis St Paul area to determine if tire pavement noise (OBSI) from the pavement surface affects perception of pavement smoothness (MPR). Forty six volunteers rode as passengers in 2010 Chevrolet Malibu sedans over the contiguous ½ mile long rigid or flexible pavement test sections scoring MPR. Results of MPR were compared to the International Roughness Index (IRI) measured with the digital inspection vehicle at the same time. The AASHTO TP 76-09 procedure for OBSI procedure for near field measurement was used to measure tire pavement noise. Using statistical analysis and tests, the MPR and OBSI were examined for correlation of the latter to anomalies in the former. OBSI did not seem to explain anomalies in MPR referenced from measured IRI. However, the sequencing of the test sections for the ride survey appeared to have influenced some of the ratings of some test sections. Moreover there was some evidence of correlation of IRI and MPR to OBSI.
This paper was submitted to the Transportation Research Board Annual Meeting in 2012.
