Bituminous emulsion and tack coat are used in the asphalt pavement to glue two layers and thus provide a nonpositive layer compound, e.g. between the existing subbase and a new surfacing or between a new surfacing and a milled-off surface.

To produce a permanent and conclusive layer compound between the single layers, the existing layer is provided with a thin coating of bituminous emulsion before installation of a new layer. Quality deficiencies as peeling or corrugations are avoided with a perfectly carried out and exactly dosed application of the adhesive layer.

Furthermore, a perfect pasting of the two layers is significant for the carrying capacity of the pavement. The bonding emulsion layer ensures the necessary nonpositive compound between the single layers. Only if this compound is guaranteed, the layer package can take over the necessary load compensation. Thus, an economic dimensioning of the road becomes possible.

The binder is spread onto the asphalt surface with a thickness of 150 – 500 g/m² directly before the asphalt application and has to be completely broken before installation of the asphalt pavement.
If the layer compound is not produced carefully, quality deficiencies occur already after a short period of time:

Break-outs of big surface parts in case of a too low dosage due to an insufficient layer compound.
Unfavourable deformation behaviour, as for example corrugation in case of a too high dosage.

Too much binder acts here as a sliding layer between the layers.

Dosage and uniformity during spreading.
The result is based on the quality of the binder used and the application process and thus especially on the machine equipment used. The equipment strongly influences the exactitude for the dosage and the uniformity during spreading.
WEIRO spreaders especially stand out due to the exact dosage of the binder to be applied so that exactly the stipulated quantity of bonding emulsion is applied.

Besides the positive effect regarding the quality, the exact observation of the necessary application quantity is also important for pure economic reasons.
The economic effects of a faulty dosage shall be proven by the following example:

ASSUMPTION: INSTALLATION OF A SURFACING

Ø length: 5.0 km
Ø width: 7.5 m
Ø total surface: 37,500 m²
Ø required application quantity: 200 g/m²
Ø material costs: 500.00 €/to.
If 300 g/m² are applied instead of the required 200 g/m² due to an inexact dosage, 37,500 m² 100 g/m² = 3,7500 kg material is used too much. In case of an assumed material price of 500.00 €/to this represents an unpaid additional expenditure of 1,875.00 €!

Example:

In case of a preselected nozzle size of 5 l/min and a set application quantity of 200 g/m² and a preselected spreading pressure of 3.0 bar the resulting running speed amounts to 105 m/min. Thus, the machinist only has to observe the running speed displayed by the electronic slow speed indicator to achieve an exactly dosed spreading result with a uniform distribution above the entire width of the spraybar

The possibility to clean lines, ramp and nozzles at the end of the work or in case of longer interruption is also of great importance for the reliability of a spreader. WEIRO spreaders are reliably cleaned with a low material requirement by evacuating lines and spraybar and blowing through the nozzles by means of compressed air.

Sprayer for the assembly on trucks or trailers for all spraying of bitumen emulsion
and tack coat in road construction and road maintenance.

The modules binder tank, binder pump and spraybar are individually adapted to the specific trucks or trailers. The following types are available:

HK 1000 PH: mounted sprayer with drive by the hydraulic plant of the carrier vehicle.

HK 1000 PM: mounted sprayer with drive by the installed diesel motor
HK 1000 A: trailer version of sprayer with drive by the installed diesel moto