Cleaning Low-Noise Surfaces as a Basic Condition for Improving Pavement’s Acoustic Absorption Capability

Abstract

Ongoing noise is a disturbing factor for humans and animals living close to roads, as traffic noise threatens residents’ health and well-being. Surfaces with noise absorption as high as 3–6 dB (so-called low-noise surfaces, LNSs) are being developed in many countries. A disadvantage is that their noise absorption decreases through their service lives. Pores become clogged with dirt within 2–3 years, stripping the LNS of its functionality. In the experiment, the noise on two surface types were measured. The first was newly developed Viaphone\({^{\circledR}}\) LNS containing organic fibres (from paper production waste). The tested surface was on a single carriageway in a residential area and on a multiple-lane carriageway in Prague. The sound pressure level (Lcpx) was measured at five testing sections in Prague before and after cleaning with pressurized water. The second road surface was porous asphalt (PA 8) containing crumb rubber (waste from worn tyre treads) and was tested in the town of Skutec. One lane of the tested section was heavily soiled by agriculture machinery exiting a field during beet harvest. There, the sound pressure levels of the clean and soiled lanes were compared. Changes in surface noise were measured using the close proximity method (according to ISO 11819-2). Cleaning the Viaphone\({^{\circledR}}\) surface increased its acoustic absorption capability by 0.8–1.0 dB(A) and for very soiled surfaces by up to 1.3 dB(A). Soiling of the PA 8 surface may have decreased noise absorption by as much as 0.9 dB(A). To maintain their noise absorption functions, LNS surfaces must be cleaned periodically.