Svein Å. Storeheier
SINTEF IKT, Akustikk
7465 Trondheim
Tlf. 73592638 / 92252953
svein.storeheier@sintef.no
Measurements of road surface texture
(2D) were carried out on a great number of pavements in Norway during the
period of 2006 – 2008. This work was part of the R&D project
“Environmentally friendly pavements” run by the Norwegian Public Roads Administration.
This report makes reference to
measurement methods and validations that were established in an early phase of
the project. Shortly, it summarises the main features of road surface texture,
and the technical units involved.
On a selection of 37 asphalt pavements
(dense type, age 1 year or more) and 8 new-laid pavements, several
investigations were carried out. The main purpose was to increase knowledge
concerning:
•
Texture in dense road surfaces and its influence in general,
•
Investigate - if possible – the relation between texture and noise (by
the CPX-method), possibly also some connection between texture and pavement
parameters,
•
The development of texture in time, especially during the first year of
operation,
•
Give examples of texture data for common Norwegian dense pavements.
The investigation had some considerable
restrictions. It was limited to noise from only one car tyre (the reference
tyre A), rolling at only one speed (50 km/h). Further, no porous pavements were
included.
The parameters of the pavements
(concerning for instance the binder, chipping size, resistance to wear,
additions, etc.) were collected.
The texture data included the texture
spectrum, and a number of texture related parameters (for instance Mpd,
G-factor).
The results showed great variation in
texture data from each type of pavement, and also between the pavement types.
The noise levels, texture data and
pavement parameters formed a basis for statistical treatment.
A simple regression analysis showed that
CPX-noise can be modelled with reasonable accuracy based on measured texture
data. The analysis in some cases indicates a connection between texture data
and pavement parameters.
The development in texture from new-laid pavements showed a relatively unambiguous pattern. The texture spectrum changes markedly during the first year. This change tends to increase the noise.