Evaluation of Trapezoidal Shaped Grooves

Figure 46. Rubber Contamination at ORD Researchers concluded that the difference in the rubber buildup on the leading edge of the grooves was due to the angular differences in the groove design, which was the same conclusion drawn at MCAF Quantico. The difference in the sharpness of the groove edges very likely determines how much rubber is caught on those edges. Researchers observed evidence of this phenomenon at several locations on the runway at ORD. In June 2009, researchers returned to ORD to conduct further evaluation of the grooves resistance to wear and durability. Researchers were able to inspect the rubber buildup that had occurred since the grooves were first installed. The airport manager explained that they were eager to groove an entire runway with the trapezoidal-shaped grooves, as they were impressed with how the trapezoidal-shaped grooves resisted rubber contamination and did not fill up with rubber deposits, as did the standard grooves. As with the feedback from MCAF Quantico, this information was valuable to researchers, as it showed that the airport made its own assessment of the trapezoidal-shaped grooves improved wear and durability and was able to appreciate a noticeable difference in their performance. During their inspection, researchers also noticed that the trapezoidal-shaped grooves were less susceptible to damage from aircraft and maintenance operations. Closer inspection of the runway surfaces showed that the edges of the standard grooves began to fail and were essentially

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