Next Generation Concrete Surface (NGCS) -Finally a quiet and sustainable road pavement?

摘要

For concrete pavements, several surface finishing techniques are possible, such as brushing and exposed aggregate concrete. The Next Generation Concrete Surface (NGCS) is a new technique from the United States, and developed to reduce rolling noise. Thanks to diamond blades, a negative texture is ground each time with 1 deeper groove and 4 shallow grooves in the longitudinal direction. This technique can be applied to new concrete surfaces as well as to existing pavements. The first Belgian trial section, composed of 2 different profiles, was carried out on an existing jointed concrete road with exposed aggregate surface in October 2015 on the N44 in Maldegem. The thickness and diameter of the diamond blades are the same for both profiles. The difference lies in the spacers, which are considerably narrower for the first profile. The Close Proximity (CPX) rolling noise measurements, performed immediately after treatment, show that for the first profile the noise level of cars decreased by 6 dB (A) compared to the existing surface. Compared with the reference pavement SMA-C (stone mastic asphalt with maximum aggregate size of 10 mm) the level obtained is 3 to 4 dB (A) quieter, corresponding to the type of AGT-mix type Ⅰ (= silent asphalt layer). For the second profile, which is rougher, the rolling noise is reduced by 2 dB (A). A year later, the difference for the first profile is 4 dB (A), while the second profile remains stable. We can therefore conclude that the NGCS is a silent pavement for cars. To ensure that the technique is sustainable, this trial section will be followed acoustically in the following years.