Comparative Analysis of Macrotexture Measurement Tests for Pavement Preservation Treatments

Field pavement preservation research concerning two accepted methods for measuring pavement macrotexture was done on a state highway in Oklahoma. The 2.5-year project used the outflow meter ASTM STP 583 and the Transit New Zealand TNZ T/3 sand circle to measure macrotexture on 23 asphalt and concrete pavement preservation treatments. Through a protocol of monthly macrotexture measurements in the field, the researchers observed functional limitations, caused by the physical mechanics of the methods, on the accuracy of macrotexture measurements on both standard tests. It was found that the sand circle should be used on pavements with macrotexture greater than 0.79 mm (0.03 in.); the outflow meter should be used on pavements with textures of less than 1.26 mm (0.05 in.). Both tests were accurate in the range of 0.79 to 1.26 mm. These results applied to both asphalt and concrete pavements.