So far, a lot has been reported on the recent suite of testing in Europe conducted by the National Concrete Pavement Technology Center. It was also reported that this work was done in concert with an ambitious testing program done in the US where, to date, over 1200 test sections have been evaluated for noise, texture, friction, and smoothness.
The question must be asked: how do US practices of texturing concrete pavements compare to those used in Europe in terms of tire-pavement noise?
First, it must be said that a lot more must be considered when comparing pavement textures. A fair comparison must include factors such as friction, durability, and cost, among others. It has been shown, however, that virtually all nominal concrete pavement textures – both in Europe and in the US – can be built low-noise and yet still excel in these other areas.
OK, so just how quiet are US concrete pavement textures?
There is a lot of variability in measuring noise. Some due to the measurement, but still a lot due to the variability in and among the pavements. With over a thousand test sections, characteristics of “populations” of similar pavement textures begin to emerge. The following figure includes a normalized depiction of the populations of the four most commonly used textures in the US: diamond grinding, drag textures, longitudinal tining, and transverse tining:
Note the levels – note the variability in the levels. The quieter of all concrete pavement textures are those that are diamond ground and with drag surfaces. Longitudinally tined also have many quieter sections, but also have more variability and can therefore also be noisy. The noisier ones are likely those that are worn and/or constructed with a more aggressive texture. Transverse tining has the most variability with some quieter sections (almost all of which have small – typ. 1/2″ – spacings), but also very loud sections with most being randomly spaced tines with large gaps (typ. 1 to 3″) between the grooves. Again, wear and quality of the concrete and construction are big factors in where a particular pavement might stand within this population.
With this information, we leave it to you to compare to the European practice as documented below. But as you compare the US to Europe – and as you compare among the various US texture types – keep in mind what other factors are also important.