SU1763412A1 - Method of asphalt-concrete mixture preparation - Google Patents

Abstract

Use: road construction. SUMMARY OF THE INVENTION: rubber crumb is mixed with a 50% solution of tar and held for 24 hours, then dissolved in oil tar at 180 - 210 ° C for 3 to 5 hours. Then mixed with mineral materials . The components of the mixture are taken in the following ratio,%: oil tar 5.3, rubber crumb 0.675 - 0.685, glycerin tar 0.015 - 0.025, mineral materials the rest. Strength at 20 ° C 1.43 - 2.3 MPa, water resistance coefficients with long-term water saturation 0.66 - 1.01. 1 tab.

Description

The invention relates to road construction, in particular to the preparation of asphalt mixes.

The asphalt concrete mix, including rubber crumb, mineral material, is known, and as a bituminous bitumen oil tar with the addition of sulfur or lime, fluff.

However, the dissolution of sulfur in the host leads to an increase in the cost of preparing the host, and also significantly increases the toxicity of the host.

There is also known a method for preparing asphalt concrete mixture, which includes dissolving rubber crumb in oil tar at a temperature of 180-250CC, followed by introducing fine sulfur in the resulting mixture with mineral material in an amount of 20-70% by weight of crumb rubber and keeping the mixture at a temperature of 160-200 ° From until the final vulcanization. The method is taken as a prototype.

The disadvantage of this method is that the introduction of various additives in tar, such as sulfur in combination with crumb rubber, leads to an increase in the cost of dissolving the rubber-containing additive in oil tar, its vulcanization in the mixture and to a sharp increase in toxicity of the asphalt concrete mix. in the process of its preparation.

The aim of the invention is to reduce the cost of sulfur emissions during the production of the mixture.

The goal is achieved by pre-mixing rubber crumb with a 50% glycerin tar solution and incubating for 24 hours, and then being introduced into oil tar, and the resulting blended material is mixed with mineral materials in an asphalt concrete mix. next

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the ratio in wt.%: petroleum tar is 5.3, rubber crumb is 0.675 - 0.685, glycerin tar is 0.015 - 0.025, mineral materials - the rest.

The method is carried out as follows.

First, a rubber-containing additive is obtained by mixing rubber crumb with glycerin tar, glycerin tar injected as a 50% aqueous solution, and the resulting rubber additive is kept for 24 hours under normal conditions, then it is injected into oil tar in the amount of 11.8–12.3% by weight of its dry matter and dissolve the mixture at a temperature of 180–210 ° C for 3–5 h.

For experimental verification of the claimed method, 6 compositions were prepared, which are listed in the table. Their properties are also indicated there.

Rubber-containing additives in formulations 1–5 were prepared in a mixing plant according to the sequence of technological operations described and mixed with mineral material. The resulting asphalt mixture is placed in the road covering by the technology of cold asphalt mixtures.

As can be seen from the table, the application of the proposed method allows a significant increase in the physicomechanical properties of asphalt concrete mixtures using tar and rubber crumb. There is no need to use sulfur, which reduces the toxicity of the material preparation and significantly reduces the emission of harmful sulfur oxides (SOa) into the atmosphere.

Glycerin tar is a waste of the food industry and has a composition in wt.%: Polyglycerol - 49.4, calcium soap - 32.8, organic residue - 14.8, water - 3.

Sulfur is absent in glycerin tar.

The amount of glycerin tar is applied to a minimum, within hundredths of a percent, which is significantly less than the sulfur addition according to the prototype.

When rubber crumb is treated with an aqueous solution of glycerin tar (PG), the latter foams, which allows it to be evenly distributed over the entire surface of the crumb rubber. During the residence time of the rubber-containing additive for 24 hours, the glycerin tar interacts with the crumb rubber and softens its surface. Glycerin tar serves as a defoamer in the process of introducing a rubber-containing additive into oil tar, which allows you to quickly raise the temperature of the mixture without fear of foaming oil tar.

The dissolution process is reduced to 3 to 5 hours, and the rubber additive used as a binder becomes more homogeneous.

The use of the proposed method allows, in comparison with the existing one, to reduce the consumption per 10–15%, shorten the dissolution time in the oil tar in oil tar to 3–5 hours, which significantly reduces energy costs and significantly reduces harmful sulfur emissions during cooking.

Claims (1)

Invention Formula The method of preparation of asphalt concrete mixture, including the dissolution of crumb rubber in oil tar at a temperature of 180 - 210 ° C for 3 to 5 hours and mixing obtained biting with mineral materials, so that, in order to reduce costs v sulfur emissions in during the production of the mixture, the rubber crumb is mixed with 50% glycerin tar solutions and held for 24 hours, and then introduced into the oil tar, while the components in the mixture are taken in the following ratio, wt.%: petroleum tar5,3; rubber crumb0,675-0,685; glycerin tar. 0,015-0,025; mineral material rest