The CP Tech Center team has recently completed testing in the Netherlands, where three unique sites were visited. The first includes a series of 41 unique test surfaces, constructed as part of the Innovatieprogramma Geluid (IPG) – a Dutch program with the objective of reducing road and rail noise. The other two sites included a single concrete pavement surface each.
The first, NL01, is an exposed aggregate concrete pavement that was constructed on N285 near Zevenbergen, HERE. Built in 2006, the concrete mix includes a “4/8 mm” aggregate, which was selected based on the results of a low-noise concrete pavement experiment conducted in 2000 by the Noord-Brabant Province, Dutch Association of the Netherlands Cement Industry (VNC), and the Dutch Information and Technology Centre for Transport and Infrastructure (CROW). Photographs of this surface are below, which can be clicked on to enlarge.
The next section was a very interesting one, as it is innovative in a number of ways. The section is a test section of a precast concrete pavement technique called Modieslab. Originally developed under the Roads to the Future program in the Netherlands, this section was built more recently – in 2006 – as a means to demonstrate this technique under heavy, high-speed traffic. Sponsored as well by the IPG as a “third generation road surface”, the section is located at the junction of the A12 and A2 motorways near Utrecht, HERE. The section consists of 3.6- x 7.2-m precast concrete panels that include a porous concrete surface. Photos of the section and the surface are found below (click to enlarge).
The on-board sound intensity levels were evaluated using the new SRTT tire at 60 mph. The resulting levels and spectra for these two sections can be found below.
As can be seen, the OBSI level for the porous concrete surface on the Modieslab is very low – just over 96 dBA. This makes it the lowest level of all of the concrete pavement surfaces measured so far by the CP Tech Center team.
As mentioned elsewhere in this blog, this measurement program can be viewed as “NITE 2”, or complementary to the Caltrans/FHWA-sponsored NITE study previously conducted by Dr. Paul Donavan of Illingworth & Rodkin. While measuring noise on numerous surfaces in Europe in 2004, a diamond ground porous concrete surface was found to be about the same level as this Modieslab section. Unfortunately, the section measured under NITE experienced durability problems, and has since been removed. However, it can be concluded from both studies that very quiet concrete pavement surfaces are possible.
The exposed aggregate section on N285 is also worth mentioning as both the level and spectra are “in between” the experiences seen in Austria and Belgium. The aggregate size is – possibly not coincidentally – somewhere in between as well.
The team would like to thank a number of folks that helped us tremendously in the Netherlands. The IPG staff was very cooperative, including Messrs. Ruud Nijland, Guido Debeus, Thijs Bennis, and Peter The. Mr. Marc Stet of VIA Aperta and Dr. Gijsjan van Blokland of M+P were also instrumental in establishing the necessary contacts. In addition, Steef van Hartskamp of the Provincie Noord-Brabant should be thanked. Finally, Mr. Rob Snijders of Arcadis and Noud van Deurzen of BETONSON have been very helpful in providing support information for the Modieslab site.