Acoustical performance of open-cell foam in longitudinal grooves on concrete roadways

Longitudinal diamond grooving of Portland cement concrete pavements can be used for the improvement of surface characteristics of concrete pavements, however, grooving has only minimal effects on tirepavement noise. Foam backer rod is widely used in the concrete paving industry for filling expansion joints between concrete slabs to seal the joints. An experiment was conducted to determine the effect on tire-pavement noise of placing open-cell foam into longitudinal grooves in concrete pavement. A grooved sample was constructed and tested with and without open-cell foam using on-board sound intensity measurements and multiple tires on Purdue University's Tire-Pavement Test Apparatus. The use of opencell foam reduces the overall intensity level emitted from tire-pavement interaction. The foam has its greatest effect at frequencies above 2000 Hz. The effects of varying the amount of backer rod used are also explored.