DE1594766B2 - Process for the production of bituminous coatings on road surfaces using a slurry of water, sand and bituminous binder - Google Patents

Description

The main application relates to a method for producing bituminous coatings Road surfacing using a slurry of water, sand and bituminous binder that the Contains binder in the form of a cationic aqueous emulsion the production of the sludge the sand first as a blocking agent a substance from the group of tertiary polyamines and one as a setting accelerator immediately before being applied to the street Added substance that reduces the pH for a short time after mixing and applying the slurry to the road is increased to a value at which the Emulsion breaks

The precipitated binder then adheres to the surface of the sand grains. The tertiary polyamines form polyvalent positive ions, which with some of their positive charges settle on the rock surface anchor and block the rock surface through their free positive charges, thereby preventing becomes that the relatively unstable cationic emulsion prematurely on the rock grains drops off

The sludges according to the main application have proven themselves very well in practice if they were used at outside temperatures between +10 ⁰ C and +30 ⁰ C, at which such work is normally carried out. However, it was found that when the slurries had to be processed in the winter months at temperatures between 0 ⁰ C and 1O ⁰ C, the setting time between the application of the slurry on the road and the formation of a navigable covering is extended very strongly cheating the setting time half an hour at normal outside temperatures, it lengthened to much more at low temperatures

ίο than an hour. A similar observation was made when the outside temperature was higher than 30 ^° C. on hot days. Here, too, the formation of a drivable film only started after a longer period of time than when working at normal temperature.

Tests have shown that the setting time obviously depends on the viscosity of the bituminous binder There is an optimal viscosity range within which the film is formed via coagulation and kalescence runs in the shortest possible time If the viscosity of the bituminous binder is above this optimum viscosity range, which is the case at low temperatures, still takes place Coagulation relatively quick, the coalescence of the coagulated droplets and thus the actual However, film formation is slow. If, on the other hand, the viscosity of the bituminous binder lies below the optimal range, which is the case at high temperatures, coagulation occurs and Coalescence on contact with the rock surface so rapidly that the rock surface immediately with a Gapless binder film is coated and thereby the breaking process does not further affect the mass of the Emulsion can continue. Emulsions that contain low-viscosity bituminous binders must be included Consideration of the higher instability a higher content of emulsifiers, stabilizers or pre-wetting agents and with these emulsions, therefore, there is this hindrance to the breaking and film-forming process particularly pronounced

The viscosity of a bituminous binder changes very strongly with the temperature, and a change in temperature of 10 ^° C. can, under certain circumstances, cause a change in viscosity of orders of magnitude. The optimum viscosity range therefore corresponds to an optimum temperature range for a specific bituminous binder, within which the film formation of this binder takes place within the desired times and without spatial interruption.

According to the invention, the slurry becomes a solvent in emulsion form shortly before use added This additive makes it possible to adjust the viscosity of the bituminous binder to change depending on the season and in particular an exact adaptation to each The prevailing outside temperature and the mineral components used in each case with the least amount of effort of solvents, emulsifiers and pre-wetting agents.

At low outdoor temperature, that is, at an outdoor temperature below 10 ⁰ C, the solvent amount of emulsion is higher, lower chosen at an outdoor temperature above 30 ⁰ C as at temperatures of 10 to 30 ⁰ C. Suitable solvents are, for example. B. xylene or white spirit can be used. The choice of the amount of solvent emulsion to be added in each case can be made on the basis of the observation of the setting behavior of the freshly applied sludge, and experience has shown that this coordination of

trained foremen can be handled in such a way that also temperature differences or different Sand qualities are evened out in this way over the course of a working day.

The addition of the solvent emulsion can be done in ·> be done in different ways. With the addition of the solution emulsion, there is no further operation in the Preparation of the slurry becomes necessary, the solvent emulsion can be used along with the slurry can be added to the setting accelerator. But you can also use the sand before the bitumen emulsion mixed, optionally together with the blocking or prewetting agent, are added. The foreman has it in hand, on the one hand through the amount of pre-wetting agent used Miscibility time, on the other hand by the amount of setting accelerator and solvent emulsion To influence the setting time and to adapt it to the given conditions. After all, the Solvent emulsion is also added to the bitumen emulsion just before the sludge is made will.

The practical tests have shown that in this way not only an adjustment of the film formation time depending on the prevailing outside temperatures is possible, but it is also less overall Solvent, less emulsifier and less pre-wetting agent required than when using a single agent Bitumen emulsion, the bitumen of which was fluxed from the outset by adding a solvent. This is jo probably due to the fact that the solvent in order to emulsify from the aqueous phase Binder particles to diffuse into it requires a certain amount of time compared to the preparation times is not to be neglected. As a result of the relatively high viscosity of the bituminous Binder is first softened the outer shell of the emulsified binder droplets, whereby the coalescence promoted and with a relatively small amount of solvent the desired effect is achieved. The subsequent addition of the solvent emulsion immediately before processing It also makes it possible to use smaller amounts of emulsifier and pre-wetting agent, since no more the stabilization during storage and transport must be taken into account, and the mixed stability not significant due to the relatively slow diffusion process during processing is adversely affected by the solvent emulsion. If, on the other hand, the binder emulsion and the Mix the solvent emulsions with one another a few days before they are used Miscibility period of the sludge overall more emulsifier and more pre-wetting agent and with the same Setting time when the outside temperature is low, more solvent can be added.

Through these advantages, namely once the possibility of a continuous adjustment of the sludge to the the prevailing outside temperature and the type of sand used and the use of the lowest possible Amounts of solvent and additional emulsifier and wetting agent result in an adaptability of the Method according to the main application, through which this method all known methods in simplicity the handling and the security with which the desired success is achieved as well as in economic Relationship is superior

In order to also enable adaptation to high outside temperatures, the bitumen emulsion according to the main application can expediently be added only a little solvent or no solvent at all, with a small amount of ^{then added when processing at normal temperatures between +10 and +30 0 C shortly before use} Solvent emulsion, when processing at low temperatures a correspondingly larger amount of solvent emulsion is added.

The following examples illustrate the practice and use of the method of the invention.

1) Sludge made from a cationic tar pitch emulsion as a binder emulsion and Anthracene oil emulsion as a viscosity regulator.

a) Tar pitch emulsion:

60 kg Teerweichpech with softening point of 35 ° to 4O ⁰ C according to Krämer-Sarnow were heated to 100 ⁰ C and under very vigorous stirring in a 80 ° C hot solution of
1.5 kg of fatty monoamine
0.5 kg of 30% hydrochloric acid and
381 water emulsified in. A finely dispersed Cu / W. emulsion was formed.

b) Pre-wetting agent:

1 kg poly (N.beta-propionic acid amide) -

propylenimine of the molecular weight
approx. 100,000 was in
96 1 water and
3 kg of 30% hydrochloric acid dissolved in the cold.

c) Anthracene oil emulsion:
In

50 kg of anthracene oil were used

2 kg fatty diamine dissolved

In this solution a solution of

1 kg of 60% acetic acid in
Let 47 liters of water flow in slowly while stirring vigorously.
When the phase was reversed, a yellow, fine Ö.iW emulsion was formed.

d) Slurry mixture, processable at outside temperatures of 20 ° C ± 10 ⁰ C.

180 kg of quartz sand with a grain size of 0/2 mm were used
11 Front net solution b) and

451 water premixed then

were within 5 to 10 seconds
2 1 anthracene oil emulsion c) mixed in and immediately afterwards

40 kg tar pitch emulsion (a). After 10 seconds of mixing time were

20 kg of ground magnesium carbonate are added as a setting accelerator and the finished slurry mixture immediately spread out on the street, wherever it is after was waterproof for half an hour and drivable after an hour.

e) Slurry mixture, processable at an outside temperature of 5 ° C:

The same procedure was followed as under d), but the mixture of quartz sand, Vorwetting solution and water instead of 21 anthracene oil emulsion 41 anthracene oil emulsion added and then the slurry mixture

as described under d),
f) Slurry mixture: can be processed at an outside temperature of 35 ° C
The procedure was the same as under d), but instead of 21 anthracene oil emulsions, only 11 anthracene oil emulsions were added to the mixture of sand, pre-wetting solution and water

2) Sludge made from cation-active bitumen emulsion as a binder emulsion and Xylene emulsion as a viscosity regulator.

a) bitumen emulsion:

60 kg bitumen with a penetration of 65 to 25 ° C

were heated to 125 ° C and with
1 kg fatty diamine added to the melt with vigorous stirring in a 80 ⁰ C warm solution of
38.51 water and

0.5 kg of 80% formic acid emulsified. A brown, smooth Ö.i.W. emulsion resulted

b) Pre-wetting agent:

1 kg poly (N-ethyl) ethylene imine with mol-

weight approx. 3000 was in
961 water and
3 kg of 30% strength hydrochloric acid dissolved

c) xylene emulsion:

50 kg of xylene was with

2 kg of a fatty monoamine mixture was added

This solution was converted into a solution of at room temperature
47 1 water and

1 kg of 80% formic acid emulsified White, stable oil-free emulsion.

d) Slurry mixture, processable at an outside temperature of 20 ° C ± 10 ° C.

200 kg of quartz sand of grain size 0/1 mm were with

15th

20 11 Front net solution (b) and
501 moistened with water
became
40 kg bitumen emulsion a) mixed in and

after ten seconds of mixing
2 kg of half-burnt ground dolomite added as a setting accelerator The finished slurry mixture was immediately spread out on the street and was waterproof after a quarter of an hour and drivable after half an hour,
e) Slurry mixture, processable at an outside temperature of 0 to 5 ° C
The procedure is as described under d), but xylene emulsion according to c) was added to the quartz sand with the pre-wetting solution or immediately before or after the addition of the pre-wetting solution. The sludge was waterproof and drivable after one hour.

Prewetting agents and xylene emulsions can be used for longer construction stretches and even weather conditions be mixed with one another in the required mixing ratio before the sludge is produced. the Sludge could be spread smoothly on the street in all cases with the usual distribution equipment.

When using sands that contain a noticeable amount of rock flour, especially when This rock flour is acid-binding, the solvent emulsion can also after the binding emulsion and possibly even added to the sludge with or after the setting accelerator. When using a screw mixer, which is known per se, the solvent emulsion can also be used through one of the successive injection nozzles alone or together with other components of the Sludge can be added, whereby it must be ensured that the mixing distance and thus the mixing time after Addition of the last component is still long enough

Claims (5)

Patent claims: 1. Method of making bituminous coatings on road surfaces using a slurry of water, sand and bituminous binder, which the binder in the form of a contains cationic aqueous emulsion, in which in the preparation of the sludge the sand first as Blocking agent a substance from the group of tertiary polyamines and immediately before Applying to the street as a setting accelerator a substance is added through which the pH a short time after mixing and applying the slurry to the road on one Value is increased at which the emulsion breaks, according to patent application P 15 94 764.5-44, thereby characterized in that a solvent is added in emulsion form to the slurry shortly before use. 2. The method according to claim 1, characterized in that the amount of solvent emulsion is selected ^{higher at an outside temperature below 10 0} C, at an outside temperature above 30 ° C lower than at temperatures of 10 to 30 ⁰ C. 3. The method according to claim 1 or 2, characterized in that the solvent emulsion of Sludge is added together with the setting accelerator. 4. The method according to claim 1 or 2, characterized in that the solvent emulsion dem Sand is optionally added together with the blocking agent. 5. The method according to claim 1 or 2, characterized in that the solvent emulsion of the Bitumen emulsion is added immediately prior to making the sludge.