- Properties of the materials used. Minimum specifications: system insulation capacity (DLr > 20 dB) and absorption capacity (DLalpha > 4 dBA).
- Reduction of the reverberant environment formed by the barrier, the train and the support structure.
- Diffraction achieved by the superior geometry of the minibar.
The effectiveness that a traditional acoustic barrier (fig x.3) provides with respect to a situation without a screen (fig x.1) is given by the shadow effect (attenuation) and the increase in the distance to be traveled by the diffracted wave. That is, the more difference there is between the direct path (blue line) and the diffracted path (orange line), the better the screen behaves.
The mini-barrier generates a larger shadow area (attenuation) and also modifies the point at which the wave diffracts, increasing the distance to travel (fig x.2). The combination of both behaviors makes the attenuation equal or higher.
The position of the highest point on the screen relative to the emission point.
The optimum operating point for our barriers is 1 meter from the railhead and 1.2 meters from the inner face of the railhead.
The shape of the barrier towards the vehicle and the flying element at the top.
The mini-barriers adopt different shapes to generate a reverberant space, which in turn allows the body of the barrier to be away from the gauge.
The noise absorption capacity.
Due to its modular plate system with large perforations and the air chamber located in the main concrete module where a highly absorbent material is placed, the mini-barrier has a great capacity to absorb acoustic emissions.
The combined effect of the absorption in the chamber with the acoustic performance of the very thick holes and the resonances in the openings allow the system to be provided with an acoustic absorption greater than 4 dB according to UNE EN 1793.1. with a smooth and resistant material that meets the requirement of non-detachment of materials and non-oxidation requested by infrastructure managers.
Diffraction.
Diffraction is the effect that occurs when an acoustic wave meets an edge. At this point the wave breaks, generating another wave train of less intensity that acts with the previous one.
The noise suppression effect occurs throughout the acoustic shadow area, i.e. at ground level and at height,
reaching to cover the totality of the surrounding facades.
Composition of the mini-barrier system:
Less visual impact due to its low height
(less than 1.2 m).
Designed to attenuate noise in urban environments: It achieves acoustic attenuation equal to or greater than that obtained with a conventional acoustic screen of 8 meters.
Suitable for traffic speeds up to 150 km/h.
Lower costs than a conventional barrier of similar effectiveness (4 to 8 meters high).
It does not present problems to the impact of wind loads, due to its weight and low height.
Does not need maintenance.
Does not require foundations.
It is adaptable to multiple additional applications.