Measure macrotexture parameters MPD, MSD, and RMS with confidence.
ICC’s texture measuring option is a vehicle-mounted device that uses a high sample rate laser to measure and calculate the pavement macro-texture and mean profile depth of the roadway surface. The mean profile depth is used to calculate the Mean Texture Depth as determined in ASTM 1845-01. The texture values correlate with a sand patch test specified by ASTM 965 and can be used to determine segregation in AC pavements. The texture-measuring package allows the user to collect and report macro-texture data at highway speeds up to 65 MPH. The device consists of a laser with a high sample rate, signal conditioning/storage electronics and a computer if purchased as a stand-alone package.
Measuring for pavement macro texture is reported as the Mean Profile Depth (MPD). The measured profile is divided for analysis into segments, with each having a 100 mm base length. If there is a slope, it is suppressed by subtracting a linear regression of the segment. The segment is further divided in half and this helps determine the highest peak in each half segment. The difference between that height and the average level of the segment is calculated. The average value of these differences for all segments makes up the MPD.
The package supports collection with 16, 32 and 64 KHz lasers. The 16 KHz lasers have a spot size of approximately 1.5mm and a resolution of 0.05mm, the 32 KHz lasers have a spot size of approximately 3mm and a resolution of 0.05mm. The 64 KHz lasers have an approximate spot size of 0.5mm and a resolution of 0.032 mm. The device is designed to interface to an existing MDR computer system or it can be supplied as a stand-alone package. The device collects macro-texture data and sends it to the MDR system in real time for display, storage and post prcessing/reporting. The system creates a summary macro-texture file and optionally stores the raw bursts of laser height data for future analysis.
System Features & Applications
ICC also offers a 3D surface measurement system. This system would find localized problems such as flushing, bleeding spots, raveling, and much more at speeds up to 65mph (100km/h). Pavemetrics LCMS will cover up to 4 meters of pavement view. It can report MPD on the entire pavement surface and simulates approximately a 4000 point rut.
When the macro-texture data is used in conjunction with a friction tester the combined system produces an IFI (International Friction Index). The data from a combined system can also be correlated to other friction measuring devices and an equivalent friction number can be reported. The macro texture MTD, when combined with the measured friction number at a measured speed, can be used to determine the friction number at other speeds.