Dyeable pavement material

The invention relates to an elastic street pavement mass comprising aggregate bound by a binder and, when needed, coloring agents and other additives, and which is particularly suitable for preparing pavements having the shade of the aggregate or being toned. The efforts made so far to replace bitumen, which is hard to dye, by a colorless binder, have resulted in the use of expensive and brittle binders. However, an economical, strong and dyeable pavement mass has now been discovered, the binder of which consists of tall oil resin, wood resin, turpentine resin, their derivatives or a mixture formed by these agents, and of a process oil softening the above resins, comprising additionally rubber and plastic as auxiliary agents. The products have a better stability and at least as high an abrasion resistance to studded tires as a conventional bitumenous pavement mass.

The invention relates to an elastic pavement mass, which comprises an 
aggregate bound by a binding agent and, when needed, colouring agents and 
other additives. The pavement mass according to the invention is 
particularly appropriate for the preparation of non-black pavements. 
Pavement masses usually consist of aggregate bound by bitumen, and they are 
cast in layers of 1 to 5 cm on top of the supporting layer of the road. 
When choosing the particle size of the aggregate, a so-called 
proportioning is applied, in which the diameter of the coarsest stones is 
c. 8 to 25 mm. The drawback of these pavements is their black colour, 
which is due to the bitumen used as a binding agent. However, the bitumen 
may be replaced by a colourless binding agent, which can be further 
pigmented to the desired tone. Colourless resin has been used as a binder 
component of pavement masses in the United States and also in Finland in 
the 70's. Petrochemical hydrocarbonaceous resins were then used, which 
were obtained from the by-product of the ethylene unit of petroleum 
refining by polymerizing unsaturated C.sub.5 -C.sub.10 hydrocarbons. The 
trade marks of such resins are Escorez 1100 or Piccopale. Petrochemical 
hydrocarbonaceous resins have, however, the drawback of being expensive 
and of failing to provide sufficiently stabile pavements. 
Tall oil rosin and its derivatives have so far been used only as pigmented 
pavement paints, which have been laid onto the pavement as a curable 
coating having a thickness of 1 to 5 mm. Such a pavement paint is brittle 
as such and does not pass the Marshall strength test intended for testing 
bituminous concrete. 
However, it has now been observed that plasticized tall oil rosin, wood or 
turpentine resin or their derivative is most appropriate as a binder of 
pavement masses. Even excellent Marshall strength values are achieved by a 
binder based on plasticized resin or its derivative. 
The purpose of the above invention is consequently to provide a dyeable, 
elastic and stable pavement mass by replacing conventional binders of the 
pavement mass by a new binder, which makes the mass both dyeable and 
tougher. Thus, the invention is essentially characterized by the facts 
mentioned in the characterizing part of the claims. Simultaneously, a new 
use has been discovered for a number of important byproducts of wood 
processing industry. 
The new pavement mass consists of the following three main components: 
aggregate, colouring and filling agents 
tall, wood and turpentine resin and their derivatives 
a plasticizing lubricating oil and its auxiliary agents 
auxiliary agents and additives. 
When choosing the aggregate, all the aggregate proportionings of asphalt 
industry are applicable. Good results have been achieved even by using 
natural moraine. In the proportioning, the coarsest stones may have a 
diameter of e.g. 25 mm, 20 mm, 16 mm, 12 mm or 8 mm. In general, a coarser 
aggregate provides a more abrasion-resistant pavement mass. An ordinary 
filler, like a lime filler or kaolin, is appropriate as a filler, either 
intermixed with the aggregate or as such. 
Any pigment of the desired shade that is stable in the preparation and 
operation conditions may be used as a pigment. Appropriate pigments are 
inorganic toners, e.g. white titanium dioxide, green chromium dioxide or 
red iron oxide. 
As a binder main component, tall oil rosin, wood resin, turpentine resin or 
any of their derivatives, which are produced by cellulose industry, are 
practicable. The derivative can for instance be a dimer, oligomer or 
polymer, or an ester with some univalent or polyvalent alcohol, such as 
trimethylpropanol, glycerol or pentaerythritol. The derivative can also be 
e.g. a metal salt of resins, whereby the metal is preferably zinc, calcium 
or magnesium. Before the di-, oligo- or polymerizing, esterifizing or 
neutralizing into salt of the resin, it can be treated with some 
unsaturated dicarboxylic acid or its anhydrid, such as fumaric acid, 
maleic acid or maleic acid anhydride. The binding agent may also be any 
appropriate mixture of the above resins and derivatives or a mixture with 
some known resin. 
The derivatives are of course more expensive than the resins, and are thus 
better suitable for special purposes. Consequently, tall resin ester, 
which is more expensive than tall oil rosin, is most appropriate for 
preparing very stabile pavement masses. 
Crystalline tall oil rosin produced by cellulose industry has proved an 
economical and practicable universal resin, the softening temperature of 
which is c. 65.degree. C. or 73.degree. C. 
In order to make a road pavement mass tough and elastic, a softening 
lubricating oil is required in addition to the rosin component. The 
lubricating oil may be any oil, like mineral oil, vegetable oil, tall oil 
or the derivatives of these. The viscosity of the lubricating oil depends 
on the preparation and operating conditions and may vary in the range of 
ISO 15 to ISO 680, preferably in the range of ISO 32 to ISO 220. A mineral 
oil having a viscosity of ISO 220 is for instance suitable for ordinary 
use. By using e.g. vegetable oils having a low pour point, more 
frost-resistant qualities are achieved and lower temperatures are 
applicable on the operating sites. 
It is advantageous to add rubber to the binding agent in order to improve 
the cold resistance of the composition. Any elastomer may be used for this 
purpose, however, the elastomers used in so-called rubber asphalts have 
proved the most advantageous, e.g. the Cariflex TR products of Shell, 
which are styrenebutadiene elastomers. 
By adding compatible thermoplastic to the binder, the thermosensitivity of 
the pavement mass may be reduced so as to avoid brittleness by cold 
temperatures and softening by heat. Appropriate thermoplastics are 
polyolefines that melt at the preparation temperature, such as 
polyethylene and polypropene, polyamides and polyesters. 
An optimal pavement mass is obtained by adding both rubber and 
thermoplastic to the binding agent, whereby the product has a good cold 
resistance combined with a high softening temperature. 
When preparing the tough and elastic pavement mass according to the 
invention, ordinary asphalt and asphaltizing equipment can be used. The 
used binder amount can vary in the range of 3 to 15% by weight of the 
total pavement mass, depending on the purpose of use. Preferably 5 to 7% 
by weight of binding agent is used at least when this agent is tall resin. 
The binding agent can contain about 10 to 40% by weight of a softening 
process oil calculated on the total mass of the binding agent, however, 
about 15-20% by weight is preferably used. 
About 1 to 20% by weight of rubber calculated on the mass of the binding 
agent can be used, whereby tall rosin together with a process oil and 
possible additives are considered binding agents. Preferably about 2 to 
10% by weight of rubber calculated on the weight of the binder is used. 
About 1 to 20% by weight of plastic is used, preferably 3 to 15% by weight 
of the mass of the binder.

The invention is explained by means of the following examples, in which the 
indicated amounts of material and conditions may vary. Examples 1 to 3 
deal with binders consisting of ordinary rosin and ordinary oils and 
example 4 illustrates a binder generating a particularly strong mass of 
resin ester and diesel oil. The pavement masses have been tested by means 
of ASTM standard D 1559 i.e. the so-called Marshall test, in which the 
power is measured, by which a cylindrical body of a length of 50 to 70 mm 
and a diameter of 100 mm is crushed. This test is the most important 
strength test of bituminous asphalt concrete. 
EXAMPLE 1 
The starting materials are: 
______________________________________ 
A. Aggregate, colouring agents and fillers: 
Material Coarseness Amount 
______________________________________ 
Crushed limestone 
0-7 mm 1 800 g 
Quartz sand 3-5 mm 1 000 g 
Sand 0-2 mm 660 g 
Lime filler (mixture) 250 g 
Kaolin 350 g 
Titanium dioxide 
(RN-56) 350 g 
______________________________________ 
and 
______________________________________ 
B. Binder 
Material Amount 
______________________________________ 
Tall oil rosin 300 g 
lubricating oil (ISO 220) 
70 g 
Polyethylene plastic (flocculated) 
18 g 
______________________________________ 
The components A are pretreated by heating in a heating chamber until 
160.degree.-180.degree. C. 
The components B are pretreated so that the tall resin is finely crushed 
and the lubricating oil and the plastic are intermixed into it, and the 
mixture is heated in a heating chamber until 160.degree. C. so as to form 
a homogeneous liquid, or the tall resin is melted at 160.degree. and the 
oil and plastic are blended by maintaining the temperature at 180.degree. 
C. 
The blending of components A and B is carried out in a "pear shaped" 
concrete mixer heated from the outside by a liquid gas flame in which the 
temperature is c. 150.degree. C. The mixing time is c. 1 to 2 minutes, at 
the end of which the composition has turned into a thick pasty or 
semi-liquid state. The pavement mass can now be poured onto the support 
for subsequent compacting or hot-rolling. 
During this example the aggregate, colouring agent and filler amounts (A) 
were kept constant, however, in the material combination B, the variations 
of table 1 were implemented and the Marshall strength values also 
appearing from table 1 were obtained. 
TABLE 1 
______________________________________ 
Test nr 
1 2 
______________________________________ 
A. components (g) 
4410 4410 
Tall oil rosin (g) 
300 300 
Lubricating oil (ISO 
70 150 
220) (g) 
Polyethylene (g) 
18 60 
Binder/mass .times. 100 
8.1% by weight 10.4% by weight 
Oil component/ 
22.7% by weight 41.1% by weight 
binder .times. 100 
Marshall value KN 
7.0 4.6 
______________________________________ 
EXAMPLE 2 
The following blending was accomplished and the working method was the same 
as in example 1. 
______________________________________ 
A. Aggregate, colouring agents and fillers 
Material Coarseness (AB 12 III) 
Amount 
______________________________________ 
Lime filler 125 g 
" 0-0.074 mm 125 g 
" 0.074-0.125 mm 175 g 
" 0.125-0.250 mm 250 g 
" 0.250-0.5 mm 250 g 
" 0.5-2 mm 500 g 
" 2-6 mm 475 g 
" 6-12 mm 600 g 
Titanium dioxide 235 g 
A Total 2 735 g 
______________________________________ 
______________________________________ 
B Binder 
Material Amount 
______________________________________ 
Tall oil rosin 160 g 
Vegetable oil (ISO 32) 
30 g 
B Total 190 g 
Binders/mass .times. 100 
6.5% by weight 
Oil component/binders .times. 100 
15.8% by weight 
Marshall value (average) KN 
6.0 
______________________________________ 
EXAMPLE 3 
In this example the component A is otherwise the same as in example 3, 
however the titanium dioxide is replaced by the following pigments: 
______________________________________ 
Material Amount 
______________________________________ 
Titanium dioxide 100 g 
Chrome dioxide 135 g (green) 
A Total 2 735 g 
______________________________________ 
______________________________________ 
B Binder 
Material Amount 
______________________________________ 
Tall oil rosin 162 g 
Process oil (mineral) ISO 220 
38 g 
B Total 200 g 
Binders/mass .times. 100 
6.8% by weight 
Oil component/binders .times. 100 
19% by weight 
Marshall value (average) KN 
8.4 
______________________________________ 
EXAMPLE 4 
The blending was carried out as follows and the working method was the same 
as in example 1. 
______________________________________ 
A. Aggregate, colouring and filling agents 
Material Amount 
______________________________________ 
Moraine 920 g 
Titanium dioxide 80 g 
Kaolin 80 g 
A Total 1080 g 
______________________________________ 
______________________________________ 
B. Binder 
Material Amount 
______________________________________ 
Tall resin ester* 90 g 
Diesel oil 18 g 
Polypropene 5 g 
B Total 113 g 
Binders/raw material .times. 100 
9.47% 
Marshall value KN 34 
______________________________________ 
* = Tall resin ester is tall oil rosin modified by fumaric acid, in which 
the esterifizing alcohol is pentaerythritol and glycerol. 
EXAMPLE 5 
The cold resistance was measured by determining the breaking point Fraass 
of a test specimen (IP 80/53) at a reduced temperature, and the heat 
resistance was measured by determining the softening point by means of the 
ring and ball method (ASTM D 2398-76). The test results of various 
compositions of the binding agent are compiled in the following table. 
__________________________________________________________________________ 
Binder composition 
Oil Breaking point 
Rosin 
Oil amount 
Rubber 
Plastic 
C..degree. 
Softening point 
Test 
g quality 
g g g (Fraass) 
C..degree. 
__________________________________________________________________________ 
1 100 ko 19 -3 i 
2 100 k220 
25 -2 i 
3 100 k32 25 -5 i 
4 100 ko 25 6 -34 i 
5 100 k32 25 7 -17 i 
6 100 k32 47 11 -36 i 
7 100 k32 25 7 10 -14 92 
8 100 ko 25 6 10 -21 44 
__________________________________________________________________________ 
Explanations: the rosin used was a soft, unconvertible tall oil rosin, the 
rubber was a SBR rubber (Cariflex Tr-1101) and the plastic was 
polyethylene. 
ko=vegetable oil 
k220=lubricating oil, having a viscosity of 220 cSt/40.degree. 
k32=lubricating oil having a viscosity of 32 cSt/40.degree. 
i=too soft to be measured by the ring and roll method. 
These compositions aim at values that are in the range of -12.degree. to 
-16.degree. C. at the breaking point, and at &gt;40.degree. C. at the 
softening point. 
The results show that rubber improves the cold resistance, however both 
rubber and plastic are needed for the product to possess both a good cold 
resistance and a good heat resistance (high softening point). One notes 
that test 8 is close to the ideal in our climate, whereas test 7 
represents the ideal composition in a temperate climate. 
By using correctly softened tall resin or its derivatives a significantly 
better adhesiveness to the aggregate is achieved than by petrochemical 
products, moreover they are noticeably less expensive and are available on 
the domestic market. It should also be noted that far more stabile 
pavements are achieved by using tall oil rosin than by bitumen. For 
instance, the Marshall value for a tall resinous pavement is 6-9 KN, 
whereas the analogue value for a bituminous pavement is 4-6 KN. The 
abrasion resistance to studded tyres is at least as high as on an asphalt 
concrete pavement. The use of vegetable oils improves the temperature 
sensitivity and frost resistance of the binder, as does a correct choice 
of viscosity in general. 
The toned and pale pavement compositions according to the present invention 
can be used on special roads, in crossings to mark a dangerous zone, in 
the shoulder part of roadways, in court-yards and porches, on pedestrian 
levels and bridges.