RU2158245C1 - Method for manufacturing asphalt and polymer-filled concrete - Google Patents

Abstract

FIELD: manufacture of road-building materials. SUBSTANCE: to mixture of mineral components preheated to 160-180 C are simultaneously added cold oil sludge (waste water treatment product obtained in bearing-working shops) and insulation tape manufacture waste supplemented by butyl rubber, each in amounts 0.35 to 0.55% of the weight of mineral components. Resulting mixture is agitated until complete encapsulation of mineral grains is achieved and thin film composed of added materials is formed. To thus activated mineral mixture, 6.0-6.5% of bitumen heated to 130-150 C is added and mixture is further agitated until homogeneous material is formed. EFFECT: reduced expenses on starting materials without loss in quality. 2 tbl

Description

 The invention relates to the field of road-building materials and can be used for the preparation of asphalt-polymer mixes used in the construction of pavements and airfield construction.

Known methods for the preparation of asphalt mixtures by modifying with polymer additives heated to 150 ... 170 ^o C bitumen. Butyl rubber, divinyl styrene thermoplastic elastomer, ethylene propylene rubber, a copolymer of ethylene with propylene, and polyethylene are recommended as such additives. (Stabnikov N.V. Asphalt-polymer materials for waterproofing industrial and hydraulic structures. - L.: Stroyizdat, 1975, 145 p.).

 Known methods for the preparation of asphalt mixtures by activation of polymer additives directly heated mineral material before combining it with bitumen. As such additives, SCSM-30 divinyl styrene rubber, DST-30 divinyl styrene thermoplastic elastomer, and fibrous waste from the manufacture of artificial fur are proposed. (Dunaenko A.V. et al. Fracture Resistance of Bitumen-Polymer Coatings of Various Structures / Bulletin of Universities. - Building, 1993, N 1, p. 57 ... 61).

The above-mentioned asphalt-polymer concrete mixtures are characterized by increased water and frost resistance (K _water = 0.94 ... 0.96, K _mrz = 0.87 ... 0.90), heat and crack resistance (K heat _. And K _Tr = 1 , 45 ... 1.52). But known methods are distinguished by the use of expensive, and sometimes scarce, polymer additives.

The closest analogue to the proposed invention is a method for preparing asphalt-polymer concrete, comprising heating mineral materials and mineral additives, introducing a cold polymer component into the mixture and then mixing it with bitumen heated to 135-150 ^o C (see ed. Certificate. USSR N 157053, IPC C 08 L 95/00, publ. 06/15/1990).

 The objective of the invention is to obtain high quality asphalt-polymer mixes of low cost through the use of polymer activating additives from industrial wastes and saving bitumen.

The problem is solved in that in the method of preparing asphalt-polymer concrete, comprising mixing heated mineral components with production waste, followed by introducing heated bitumen into the resulting mixture, the mineral components are heated to 160-180 ^o C and mixed with cold production waste introduced simultaneously - oil sludge - product wastewater treatment, which is formed at enterprises during the processing of bearings and the composition KO-2 - waste production of insulation tape with the addition of butyl rubber, in 0.35-0.55% by weight of the mineral components each is mixed until the grains of the mineral components are completely enveloped and a thin film is formed on them, after which bitumen is heated to 130-150 ^o C in an amount of 6.0-6 , 5% and mix until a homogeneous mass.

 In the method of preparation of the asphalt-polymer-concrete mixture, oil sludge is used - a product of wastewater treatment formed at engineering enterprises in the process of mechanical and thermochemical processing of bearing parts.

Oil-slag in the dry state is a highly dispersed (S _beats = 710 ... 770 m / kg) mineral powder, hydrophobized with used industrial oils (diesel, turbine, cylinder). The mineral part of the scale contains particles of metal, abrasive, calcium and magnesium carbonates. The ratio of mineral and organic components is 1.5: 1 ... 1: l, respectively. In the method of preparation of the asphalt-polymer concrete mixture, the waste of production of insulating tape - KO-2, formed at enterprises producing insulating materials, was also used.

Composition KO-2 is made from waste that is formed when cutting the edges of a plastic film on the cutting machine - the basis for the insulation tape. These edges are processed with the addition of butyl rubber (BK 1675). Ready-made KO-2 consists of granules powdered with talc in order to prevent and stick together. The composition of KO-2 includes the following ingredients:
high pressure polyethylene (LDPE) - 1.0
low pressure polyethylene (HDPE) - 0.36
soot - 0,024
stabiloil - 0,055
BK 1675 - 2.9
petroleum resin - 0.11
talc - 0.23
ZnO - 0.011
antioxidant - 0,0014
The total uterine mixture - 4.73
In the table. 1 and 2 show examples of a specific implementation of the method of preparing the asphalt-polymer mixture and the properties of the asphalt-polymer concrete.

 As can be seen from the data in Table 2, asphalt-polymer concrete (compositions 2,4,5,6) prepared by the proposed method is distinguished by improved heat and crack resistance, water resistance compared to the original (composition N 1).

 This is due to the fact that, during the modification of mineral components, an oriented (structured) film is formed from a mixture of polymers (LDPE, HDPE, BK) and oil sludge, which contributes to a significant strengthening of the bitumen – mineral grain interfacial contact.

 In turn, this affects the increase in waterproofing and stabilization of strength (deformed) characteristics of asphalt-polymer concrete in a wide range of operating temperatures.

 The orientation mechanism of the 2-phase system "polyethylene butyl rubber", to which KO-2 belongs, is as follows. Particles of the dispersed polymer phase - polyethylene are converted from a relatively spherical shape into long threads. A more complete relaxation of internal stresses in the butyl rubber polymer matrix occurs as a result of a decrease in its viscosity and the formation of a highly developed surface. The viscosity of butyl rubber and the rigidity of polyethylene are “softened” with a plasticizer - a mixture of oil sludge oils, the latter, acting as a low molecular weight solvent, reduces the internal friction of polymers in the melt state and, facilitating the thermal movement of macromolecules - the mobility of their meshing sites, promotes the formation of an oriented (structured) film on the surface mineral grains (Kuleznev V.N. Polymer blends (structure and properties). - M .: Chemistry, 1980; Vlasov S.V., Kuleznev V.N. Oriented state of polymers / Chemistry, 1987, N 5). But the composition of N 2 does not provide a significant increase in the above indicators. Apparently, this is due to the insufficient amount of introduced modifying additives and the formation, in this regard, of intermittent oriented films on the surface of mineral components. Such films, as you know, contribute to the formation of a contact structure in asphalt concrete, which is reflected in its operational characteristics (Lysikhina A.I.

 Composition N 6 significantly reduces the strength characteristics of asphalt-polymer concrete. Obviously, this can be explained by the fact that excess plasticizer facilitates disorientation processes so much that the proportion of plastic deformation increases and, accordingly, the orientation of the macromolecules of the polymer mixture and the film strength on the surface of the mineral components decrease. In addition, excess waste KO-2 contribute to the formation of thicker films, which are known to have significantly lower strength than in the oriented (structured) state. (Kolbanovskaya A.S., Mikhailov V.V. Road bitumen. - M.: Transport, 1978, 264 p.).

 The optimal results that meet the goal are shown in the compositions N 3, 4, 5 (tables. 1 and 2).

From the analysis of the results it follows:
water resistance of asphalt-polymer concrete increased by 1.06 - 1.1 times;
heat and crack resistance increased by 1.4 - 1.6 times;
bitumen consumption decreased by 8 - 16%.

 The analysis by the applicant on scientific, technical and patent sources of information made it possible to identify distinctive features in the declarative technical solution, therefore, the claimed method of preparing a bitumen-polymer mixture meets the criteria of the invention of "Novelty". The information found does not contain information about the indicated technical result and the influence of individual features on the achievement of the technical result is not revealed from it. Therefore, this technical solution meets the criterion of "Inventive step".

 The criteria of the invention "Industrial applicability" is confirmed by the fact that the proposed method for the preparation of asphalt-polymer concrete based on an activated mineral component with oil sludge and KO-2 does not require additional energy costs for its implementation. It allows widespread use of industrial waste and, thereby, expanding the raw material base of relatively expensive polymer additives, but also reduce environmental stress in regions where significant land is allocated for the disposal of such waste.

Claims (1)

A method of preparing asphalt-polymer concrete, comprising mixing heated mineral components with production wastes, followed by introducing heated bitumen into the resulting mixture, characterized in that the mineral components are heated to 160-180 ^o C and mixed with cold wastes introduced simultaneously - oil sludge - a waste water treatment product formed at enterprises during the processing of bearings and the composition KO-2 - waste production of insulation tape, with the addition of butyl rubber in the amount of 0.35-0.55% of ma The mineral deposits of each of the components are mixed until the grains of the mineral components are completely enveloped and a thin film is formed on them, after which bitumen heated to 130-150 ^° C is introduced into the mixture in the amount of 6.0-6.5% and mixed until a homogeneous mass is obtained.

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