NL9002315A - Sound absorbing wall - has helm-hole air body resonators and open cell concrete to absorb high and low frequencies - Google Patents

Abstract

Sound absorbing wall (1) comprises layer of open-cell material facing traffic, having a relief, enlarging the surface for radiating sound. Resonance chambers (15) of helmholz air body resonators are located behind this surface which contain sound absorbing material (16). The open-cell material absorbs high frequency sound, and the helmholz air body resonators absorb low frequency sound. The panels are pref. formed from open cell concrete. The wall (1) can run alongside a road formed from open cell bitumen. @(11pp Dwg.No.9/12)@.

Description

SOUND ABSORBING WALL

The invention relates to a sound-absorbing wall for absorbing traffic noise.

The known sound absorbing walls are generally good at absorbing the high tones, such as 1000-2000 Hz, from the sound spectrum, but insufficiently attenuate the low tones, such as 60-125 Hz, which arise from tire noise and engine noise from freight traffic.

In this regard, the invention provides an improved sound-absorbing wall, which is indicated in claim 1.

Further features of preferred embodiments of this sound-absorbing wall are apparent from the following description, with reference to drawings. The drawings schematically represent:

Figure 1 shows a perspective view of a sound-absorbing wall according to the invention at the location of a viaduct;

Figure 2 is an enlarged vertical section along line II-II of figure 1;

Figure 3 on a larger scale a horizontal section along line III-III of figure 2?

Figure 4 shows a section corresponding with figure 3 through two other embodiments of the sound-absorbing wall according to the invention.

The sound-absorbing wall 1 of figures 1-3 is arranged along a traffic road 9 and has a supporting structure 3 extending into the ground 2, consisting of a plateau 4 and vertical supports 5. On this is supported a supporting structure 6 of reinforced structural concrete or steel and against which the sound-absorbing wall construction 7, which is built up of three plates 18, which mutually enclose an obtuse angle, so that the side 10 facing the traffic route 9 is hollow. The plates 18 interlock with a complementary joint 11 and in a foot beam 12. The plates 18 have panels 8 on their front side which are made of open-structure concrete. The panels consist of a closed rear wall 13 and a T-shaped building element connected to it as a whole, the flange 14 of which faces panel 9 as panel 8. The flanges 14 are at a mutual gap distance a of 25, 15, 35 or 50 mm. Behind the flanges 14 are T-shaped cavities 15, in which, according to Figure 3, fibrous material, for example glass wool, mineral wool or the like, sound-absorbing soft material 16 is incorporated.

The sound-absorbing wall according to the invention has an aesthetically pleasing appearance.

The wall elements 19 are pushed together while inserting insulating material. Any sand is poured in from above through a corresponding opening.

In the embodiment variant of figure 4, panels 8 of open concrete structure are first manufactured, wherein fixing reinforcement 20 of reinforcement 21 protrudes outside panels 8. Subsequently, a building element 23 is manufactured by placing a series of panels 8 on a plane at a mutual distance a and by placing bodies of sound-absorbing material 16, for example, open-cell, elastic polyurethane foam thereon. Then reinforcement 24 of the rear wall 13 is set and attached to the fixing reinforcement 20 and then the construction concrete 25 of the rear wall 13 is poured. The factory-built construction elements 23 in series are transported to the construction site and arranged there, for example according to figure 2, either in curved plane or in straight plane.

The dimensions and dimensions in mm that are given as an example can be derived from the drawing. These sizes can vary considerably within their order of magnitude.

Claims (7)

A sound-absorbing wall for absorbing traffic noise, comprising a number of spaced-apart traffic-facing panels, with cavities behind the panels containing sound-absorbing material, which cavities are in communication with those present between the panels crevices. Sound-absorbing wall according to claim 1, characterized in that the panels are made of open-structure concrete. Sound-absorbing wall according to claim 1 or 2, characterized in that the panels form part of a T-shaped building element. Sound-absorbing wall according to claim 1, 2 or 3, characterized in that the cavities behind the panels have a T-shaped profile. Sound-absorbing wall according to one of the preceding claims, characterized in that the cavities present behind the panels are filled with sound-absorbing material, for example fibrous material. Sound-absorbing wall according to one of the preceding claims, characterized by three panels in vertical cross-section which form an obtuse angle, so that the side facing the traffic is hollow. Sound-absorbing wall according to any one of the preceding claims, characterized in that it comprises building elements, each comprising panels of open structural concrete arranged at mutual distance a and a rear wall of structural concrete arranged therebetween, in which bodies of sound-absorbing material are embedded.