Reduction of Tire-Pavement Noise by Porous Concrete Pavement

Abstract

This study investigates the effect of Portland cement porous concrete on tire-pavement noise reduction. The acoustical absorption coefficients were measured in the laboratory for porous concrete materials representing combinations of various maximum aggregate sizes, gradation, layer thickness, and composition layers. The laboratory results indicated that porous concrete with a maximum aggregate size of 9.5 mm had the highest acoustical absorption coefficient. They also showed that the peak absorption coefficient depends on the mixture characteristics and the thickness of the specimen. A thickness of 80 mm had optimum absorption. The results from the laboratory study were used to design and build a test road in the field with two test cells. The wet-on-wet construction method was successfully used to build the porous cement friction course over conventional concrete pavement. Tire-pavement noise was measured on the test cells using the close-proximity method under various vehicle speeds and different tire treads. Tire-pavement noise also was measured for other pavement textures to quantify the noise-reduction effect of the porous cement concrete pavement. The field-measured tire-pavement noise clearly showed that the porous cement concrete significantly reduced the tire-pavement generated noise by 4 to 8 dB.