New Technique for Silencing Existing Concrete Roads

Some concrete roads have been constructed and finished or textured that lead to an unfavourable texture. This kind of textures can lead to unacceptable high noise levels. However, from the civilengineering point of view these roads can be very durable. In those cases, only the surface needs a treatment to lower the noise emission. A new combination of techniques has been derived by a Belgian concrete treatment specialised company. The combination consists of a number of diamond blades composing a grinding cylinder with increased spacing followed by a rib breaking device. The longitudinal grinding grooves reduce the noise and the length evenness improvement results in extra noise reduction and smoother rideadability. In order to reduce further the low frequent noise an extra treatment smoothes the remaining ridges that are in direct contact with the tyre. This technique, however, can also be applied on newly put low-noise concrete roads to further increase noise reduction. Noise measurements on a one year old road with middle sized exposed aggregate showed an improvement for passenger cars and lorries of 2 dB(A) and 3 dB(A), respectively. After one year, due to positive wear under traffic the effect for passenger cars slightly reduced to 3 dB(A).