RU2354622C2 - Gel-forming bonding agent for obtaining cold asphalt concrete repair mixes - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: gel-forming bonding agent for obtainment of cold repair mixes includes bitumen, diesel fuel, adhesion additive, gel-forming additive. Distilled tallol and caustic soda are used as gel-forming additive at ratio, wt %: tallol 85-90, caustic soda 10-15. Component ratio in gel-forming bonding agent, wt %: bitumen 82-85, diesel fuel 15-18, gel-forming additive 1-2.

EFFECT: possible obtainment of cold repair mix with high content of bonding agent, stable internal structure of bitumen in wide temperature range, wearing resistance.

1 cl, 2 tbl

Description

The invention relates to road-building materials used for the preparation of cold asphalt repair mixtures for the repair of road surfaces.

The problems of repairing the road surface (pits, potholes, the formation of cells) are directly related to the used repair mixtures. Cold mixtures used during repairs do not create a sufficiently homogeneous structure with the existing coating, have a low bitumen content (a thin film on the surface of crushed stone), which leads to poor adhesion of the stone material during compaction, gradual chipping.

Known binders for repairing road surfaces, usually containing surface-active substances (surfactants), for example binders for repairing road surfaces (1) (RF Patent No. 2280014) based on bitumen and surfactants - “carboxypavous”. The use of surfactants can prevent caking, increase adhesion to mineral materials. The disadvantage of this composition is the following: it contains three chemical additives, which, on the one hand, complicates its preparation, and on the other, significantly increases the cost of the composition. In addition, as a rule, the main technical result when using surfactants is the expansion of the list of surfactants used in the preparation of cold asphalt mixtures used for road repair. Bitumen-mineral mixtures for repairing asphalt-concrete coatings are known (2) (Bitumen-mineral mixtures for repairing asphalt-concrete coatings on public roads and city streets of TU 5711-003-03445377-2003). The bitumen-mineral mixture is a rationally selected mixture of mineral materials (crushed stone, sand and their mixtures) obtained by mixing in mixing plants with organic binders (liquid or liquefied bitumen) and active additives PVA (polyvinyl acetate) and DOROS-AP adhesive additive.

The disadvantage of this mixture is the fragility of the storage of the mixture and the need for constant mixing during storage. As a rule, the cold mixtures used during repairs do not create a sufficiently homogeneous structure with the existing coating, have a low bitumen content (a thin film on the surface of crushed stone), which leads to poor adhesion of the stone material during compaction, and gradual chipping.

The closest to the claimed object in terms of features is a gel-like bitumen developed in the USA (3), which is modified with a special additive in the form of MAK powder, which incorporates a polymer that changes the internal structure of bitumen, forming something in the form of a spatial grid or “sponge” that holds the bitumen within itself. Diesel fuel or kerosene is used as a diluent (“Construction equipment and technologies” No. 6, 2005).

In the laboratory of the FSII Research Institute of SM of Tomsk, MAK powder was tested to modify bitumen and transfer it to a gel state. Studies have shown the benefits of gelled bitumen. When mixed with stone material, the binder forms thicker films on its surface. In this case, gel-like bitumen does not flow from the surface of the stone, as a result of this, more strong bonds are formed. Thus, it is possible to create highly gravel mixtures with a rigid stone frame in a compacted state. As a result, areas of asphalt concrete pavements during repair with cold mixtures using gel-like bitumen have higher durability, strength and shear resistance. The use of packaged cold repair mixtures expands the possibilities of repairing coatings in spring and autumn at lower temperatures.

However, significant shortcomings were revealed in the technology for the preparation of a gelling binder based on MAK powder (USA):

- high temperature of bitumen with the introduction of MAK powder 190 ° C;

- high melting point of MAK powder;

- unsatisfactory solubility of MAC powder when the temperature of bitumen is lower than 180 ° C;

- high temperature storage gel-like binder - 180 ° C with constant stirring;

- high cost of 180-200 rubles / kg.

The objective of the invention is the creation of a gelling binder for the preparation of cold repair mixtures, simplifying the technology of preparation of a binder, reducing toxicity, replacing expensive imported additives. The essence of the invention lies in the fact that in a gel-forming binder for the preparation of cold repair mixtures, including bitumen, diesel fuel, tall oil and caustic soda are used as a gelling additive in the ratio, wt.%:

tall oil - 85-90

caustic soda - 10-15

in the following ratio of components in the binder, wt.%:

bitumen - 82-85

diesel fuel - 15-18

gelling additive - 1-2.

To improve the adhesion properties, the binder may contain an adhesive additive.

A gelling additive is a composition comprising distilled melt oil (DTM) 85-90% and caustic soda 10-15%.

Distilled tallow oil, an oily liquid, transparent at 80 ° C.

Caustic soda - caustic sodium, flaked TU 6-01-1306-85.

A gel-forming additive is obtained in a jacketed reactor into which a high-temperature coolant is supplied. With intensive stirring of taly oil, saponification with caustic soda is carried out at a temperature of 190-200 ° C for 60-80 minutes. After cooling, a pasty mass of dark brown is formed with a melting point of 80 ° C.

Studies conducted at the Federal State Research Institute for Scientific Research SM showed that the gel-forming additive not only is not inferior in its properties to the MAG powder, but has several advantages:

- the temperature of the bitumen with the introduction of additives has a range from 110 ° C to 180 ° C;

- the melting temperature of the gel-forming additives 70 ° C. When heated to a temperature of 90-100 ° C, it can be introduced in a liquid state;

- good solubility in bitumen;

- low price.

With the combined use of an adhesive additive BAP-DS-3 (TU 2482-005-33992933-2003) and a gelling additive, the adhesive properties of the binder are improved.

A gel-forming binder is prepared in a conventional asphalt mixer as follows: a gel-like additive preheated to a temperature of 90-95 ° C is introduced into bitumen heated to a temperature of 110-80 ° C with constant stirring for 20-30 minutes until a homogeneous mass is obtained.

A gel-forming binder was tested in accordance with GOST 12801.

Table 1 shows the compositions of the gel-forming binder.

Table 1 No. p / p Gelling Binder Components Content, wt.%, To bitumen in composition one 2 3 four 5 6 7 one MAK powder 1.45 - - - - - - 2 Gelling agent - 1.0 1.5 2.0 1.0 1.5 2.0 3 Adhesive additive BAP-DS-3B - - - - 0.7 0.7 0.7 four Diesel fuel fifteen fifteen fifteen fifteen fifteen fifteen fifteen 5 Bitumen rest

Cold asphalt mixture is prepared as follows.

Mineral materials containing 70% coarse aggregate up to 5 mm and 30% fine aggregate less than 5 mm without preliminary drying and heating are fed into a forced-action mixer and mixed, after which a gel-forming binder heated to 90-100 ° C is introduced in an amount of 7% and adhesive additive to 100% of the mineral component and continue to mix until a uniform coating of mineral particles with the binder is obtained. Water resistance and water resistance during prolonged water saturation are shown in table 2.

table 2 No. p / p Indicators Compositions Indicators according to GOST 9128 one 2 3 four 5 6 7 one Water resistance 0.63 0.72 0.81 0.79 0.82 0.85 0.79 0.8 2 Water resistance with prolonged water saturation 0.55 0.58 0.62 0.63 0.71 0.73 0.62 0.6

These indicators are very important and affect ductility and durability. Thus, cold asphalt concrete meets regulatory requirements.

The implementation of the claimed invention ensures the achievement of its main goals: the ability to create cold repair mixtures with a high binder content, providing a stable internal structure of bitumen in a wide temperature range and resistance to aging.

Used sources

1. RF patent №2280014, С04В 26/26. A binder for repairing wet roads / Kulik E.P., Kocherga V.G., Tarasovich A.P., Sheikhet I.M. No. 2004131355/034. Declared 10/26/20044. Published 2006.04.10., Bull. No. 20, Priority 10/26/2004.

2. Bitumen-mineral mixtures for the repair of asphalt concrete coatings on public roads and city streets TU 5711-003-03445377-2003. Registration number 001973. Tomsk Regional Directorate of Road Fund and Highways, Tomsk 2003.

3. Maryshev B.S., Pozdnyakov V.R. Multifunctional asphalt mixes on bitumen modified with MAK powder. - Construction machinery and technology. - 2005. - No. 6 (prototype)

Claims (2)

1. A gelling binder for the preparation of cold repair mixtures, including bitumen, diesel fuel, characterized in that distilled tall oil and caustic soda are used as gelling additives, in a ratio, wt.%:
tall oil 85-90 caustic soda 10-15
in the following ratio of components in a gel-forming binder, wt.%:
bitumen 82-85 diesel fuel 15-18 gelling agent 1-2 2. The gel-forming binder according to claim 1, characterized in that it further comprises an adhesive additive, wt.%: 0.7-0.9.