The objective of the EU financed project ROSANNE is to advance harmonization of measuring rolling resistance, skid resistance and noise emission of road pavements and prepare for standardisation. As a part of ROSANNE the relationship between acoustic properties of road surfaces, as measured using the CPX and SPB methods, has been studied. The data are from five parties from five different countries, measured with different equipment and on different types of pavement. The data have been analysed in two groups; CPX and SPB performed at the same reference speed, and CPX measured at 80 km/h while SPB was measured at 110-120 km/h, respectively. The relationship found for passenger cars between the CPX and SPB noise levels measured at 1.2 m height at the same reference speed is L_(SPBP)=0.95·L_(CPXP) -15.6 dB, and for multi-axle trucks L_(SPBH80)=0.65·L_(CPXH80) + 24.0 dB. The relationship for when measurements are made at different reference speeds is less clear. SPB measurements are performed at other heights than 1.2 m, and the influence of increasing the measurement height was studied. For dense surfaces the average noise level seems to decrease by 0.5 dB per meter the microphone height is increased, whereas the SPB noise levels are almost independent of height at porous asphalt.
展开▼
