DE1813626B2 - SPRAYING OF SURFACES OF BITUMINOES, SPLIT TRAFFIC AREAS - Google Patents

Description

For the maintenance of subordinate traffic areas, such as parking lots, secondary roads and agricultural roads, has in addition to the usual hot paving methods with bituminous mix as well the so-called surface treatment still has a lack of importance. This is known By spraying the traffic areas with a bituminous hot binder such as hot tar or Vcindiiilübiiurncr !, or with a cold binder. “Ie cold bitumen or kahasphalt, followed by chipping with broken rock material. executed. The result is a very grippy road surface, but this in addition to this advantage also has a number of disadvantages.

Even after careful rolling and sweeping before the traffic handover, part of the Stone chippings are too weakly bound and, in the form of the well-known loose chippings, lead to considerable traffic hazards due to broken windshields and risk of slipping. If the gating is too weak With binding agent, the grit material is also removed again, especially in the lanes And then results in an uneven and unsightly appearance of the road surface. The same thing happens. v if the bituminous binder used becomes too soft during the summer months and consequently becomes too soft pushes up under the traffic. For the reasons mentioned, the described Paving method on heavier traffic. Roads are hardly used anymore.

Attempts have already been made to overcome these difficulties by using the methods described in US Pat Art treated surfaces then with a bituminous slurry, i.e. with a mixture Coated from bituminous emulsions and sand. This makes the grit material uniform firmly bound, but on the other hand the very desirable good grip of the surface treatment is achieved ! hereby canceled again. Therefore, one has already tried to better bind the grit through Overmolding of the rolled and swept pavement with one of the usual bituminous cold binders, such as cold bitumen or kahasphalt.

The structure of the surface is retained if only a small amount of these binders is used, because the greater part of the binding agent disappears in the pores between the individual rock grains. Ek cannot be avoided, however, that a sticky and especially at higher temperatures greasy surface arises.

It has now been found that the difficulties mentioned can be avoided if the after spraying with a bituminous binder, chipped and rolled off and then through Sweeping away of loose grit material freed of chipped traffic areas instead of one of the usual ones Bitumen emulsions, which are produced by emulsifying heated soft bitumen by means of capillary-active substances have been produced, over-sprayed with such bituminous dispersions, which with the help of swellable minerals such as clay or bentonite are produced. Such bituminous emulsions with clay as emulsifying agents are known. The addition of plastics, in particular elastomers, to these is also possible Clay emulsions known from the Dutch laid-open specification 6 617 297, in which the use these emulsions for road building purposes is described. However, this is Mixtures with sand in the form of so-called slurries. Such sludges have dried up a fine roughness that is sufficient for many cases. But this roughness is not enough for Roads that are fast or winding, or those with extreme gradients. This is especially true for runways at airfields, where high braking forces are also absorbed by friction

This known dispersions with sound ah emulsifying agents have the property that they have a much higher softening point after drying as the starting binder. In general it is. that the dried dispersions no longer melt at all when heated, but only sinter together at temperatures above 150 C. For example, a bitumen of type B 200 with a softening point of 40 ° C is emulsified in a ratio of 1: 1 in a 5 percent clay slurry and this slurry is allowed to dry to a 5 mm thick layer in a dish. in this way, this shell can be heated up to 150 ° C. in a vertical position without the bituminous layer flowing together. If, on the other hand, molten bitumen of type B 200 is mixed with the corresponding amount of clay powder, the softening point only increases from 40 to about 45 ° C.

As has been found, these dispersions are now particularly suitable for spraying bituminous, split traffic areas. The invention thus relates to the use of bituminous Aqueous dispersions containing substances which contain swellable minerals as dispersants, for overmolding surfaces of bituminous, by spraying with any bituminous Binder and chippings produced traffic areas, creating a surprising improvement the road surface with regard to the fixation of the coarse gravel. the coefficient of friction and the temperature resistance is achieved.

The swellability of the dispersants used in the case of overmolding in There is no question of coming thin layers with generally only 0.2 to 0.5 mm dry film thickness Disadvantage. On the contrary, the impermeability to water is thereby improved. Just the possibility swelling of the clays has hitherto prevented those skilled in the art from using such dispersions in road construction.

That there was a prejudice against cohesive (swellable) minerals can be seen in the paperback "Bitumen and Asphalt", 1957, p. 373, paragraph 461.0. The skilled person can learn from this infer that clays, by swelling with water, reduce the strength of the respective coating.

Zen. Even sludge, which is usually only found in all pores that have not yet been filled

Layer thicknesses of 3 to a maximum of 5 mm can penetrate road and split grains. From this it follows

cover applies, normalAveise does not mean that the amount to be used is different from that for the

Clay emulsions, but with stable or semi-siabi surface treatment used

len ionic emulsions produced which depends on the 5. When using grit 2 ~ to 5 mm

When it dries up, it is by no means capable of swelling, but when it is too the maximum overmolding is expedient

high stability are re-emulsifiable. 1 ks. m ² SO percent bitumen dispersion, with grit

The usual embodiment of the surface bemaFerial 5 / S with a maximum of 1.5 kg and for chippings is based on spraying the asphalt rial 8 12 with a maximum of 2 kg, road with such an amount of binding agent (in ge or emulsion form) that about 60 percent of the bituminous dispersions used on the area Rock chippings to be sprinkled after the rolling pre-base of swellable minerals also offer the gang are embedded in the binder. This single advantage that a much wider range of Embedding is sufficient for heavy loads from pusher-type bituminous products used for emulsification do not have the strength to hold the grit, ins- 15 can be.

special then, if aas used connective- While by means of capillary-active substances only

medium becomes too soft at higher temperatures or relatively soft distilled bitumen grades are emulsified

if (at airfields) the jet can be used, it is possible with the help of the aqueous suspension

starting machines or swellable minerals due to the frictional heat, also hot

the attached chassis an additional tar, tar-bitumen combinations, blown and

warming occurs. The chippings are partly semi-blown bitumen and combinations of

torn out and the coating in the Fahr- bituminous products with elasticizing product

tracks quickly destroyed. Is made by using such as natural rubber and synthetic rubber, too

to disperse the grit with an increased amount of binder. This also applies to the binding agent

better embedded, there is a risk that, in particular, increased stability and a certain elasticity

Particularly in the case of a subsequent grain modification, the process-based surface treatment was done

a smooth and thus achieved by traffic densification.

A surface that is liable to slip is created. It is also possible to use the swellable minerals

It does not matter whether the additional BincU-rr.ittel amount of containing, aqueous dispersions is bituminous

from the start or by subsequently injecting 30 products not only for the over-

(so-called head injection) is applied (see here injection, but also for the injection

to »Bitumen and Asphalt ?. Paperback 1957. The old ceiling has to be splintered before splitting off.

P. 335). turn around.

When using the stabilizers according to the invention, the following examples serve to illustrate

The described Glattwer- 35 of the invention occurs in larger clay emulsions,

that of the surface. The BeisDiel 1 additional amount of binder used envelops the

protruding chippings with an even layer - a surface that can be removed by spraying 1.3 kg. ηι-strength. without a uniform and thus smooth cationic cold asphalt and chipping with 12 kg Surface to flow together. The original grippy moraine chippings with a grain size of 5 to 8 mm are treated by workcit is thus fully preserved, and the grain is as it is after rolling and sweeping with it embedded that regardless of the temperature of a bituminous dispersion consisting of significantly higher thrust forces are absorbed

can. The exclusive use of clay - 50 percent by weight of blown bitumen from

emulsion for head spraying offers the advantage of 45 softening point 65 ° C (ring and ball

that the usual quick method for the first injection),

breaking ionic emulsions are used 5 weight percent clay and

can, which cheaper and weather-independent 45 weight percent water, are.

As a result of the properties of the bituminous 5? overmolded in an amount of 1.2 kg / m ² . After this

Nous dispersions on the basis of swellable leads - drying results in a coating that is also very good

the stickiness described at the beginning can lead to a significant amount of grit

does not lose grain when overmoulding the surface treatment and even at irradiation temperatures

Enter, rather the result is a cementing of the ren of 50 ° C does not sweat.

Grit material, which even at high summer 55 _R. . . _7th

Irradiation temperatures is maintained. The egg also spat "

so dreaded sweating of the road surface in the The asphalt runway of an airfield is used in order to

Summer can now be avoided, because roughening and achieving a certain resistance

by overmolding the finished surface against fuels with 1.5 kg / m ^{2 of} a bituminous di-

action, it is possible to inject the 60 spersion, which is made by dispersing

old ceiling used amount of binder less than 50 parts by weight of a mixture of 90 weight

set without the risk of an insufficient percentage of hot tar and 10 percent by weight of nitrile

the binding of the rock chippings. rubber or 10 weight percent chloroprene in

The one for overmolding the finished surface - 50 parts by weight of a 5 percent by weight clay treatment The dispersion used should expediently be prepared. This is followed by asphalt In terms of their quantity and concentration, the grain size is split between 1 and 3 mm and then split off on the one hand provides the grip of the upper rolling and sweeping with 0.4 kg / m of the sliding surface remains fully intact and, on the other hand, the effect of spraying over dispersion.

Claims (1)

Claim: Use of aqueous dispersions containing bituminous substances, which are used as dispersants Contain swellable minerals, for spraying surfaces of bituminous, through Spraying with any bituminous binding agent and rinsing produced traffic areas.