CS259296B1 - Antifreeze synthetic aggregate for the wearing layer of bituminous road and pavement covers - Google Patents

Abstract

The solution prevents the formation of ice and the associated slipperiness on bitumen roads and sidewalks in the winter months. The formation of ice is prevented by the addition of synthetic aggregate containing sodium chloride, added to the wear layer of bitumen road and sidewalk surfaces. Synthetic aggregate is essentially a hardened, crushed mixture containing in mass percentages 40 to 70 wt. % technical sodium chloride, 10 to 20 wt. % granite crushed fraction 0 to 4 mm and 20 to 40 wt. % cement SPC 325-600. Synthetic aggregate is added to natural aggregate intended for the production of bitumen mixture according to the desired effect in an amount of 10 or more wt. %. The active deicing component — sodium chloride — is released from synthetic aggregate over a long period of time as a result of abrasion of the surface by the wheels of vehicles.

Description

BACKGROUND OF THE INVENTION The present invention relates to anti-freeze synthetic aggregates for the wear layer of bituminous pavements and pavements.

Under certain weather conditions, in winter months on wheelchairs and sidewalks, it creates frost, pofadovica and layered snow, which increase slippage and thus reduce road safety. flow reducing the freezing point of aqueous solutions. In the Federal Republic of Germany, Switzerland, Austria, France, Denmark and the United States, the defrosting agent is expanded to "Ver, li-mit" bitumen blends. In Czechoslovakia, a similar calcium chloride coating is patented in the form of granules coated with a melt of molten polymers. A similar principle is based on a product where instead of calcium chloride, a crystalline soda ash chloride is used, and a cementitious powder. A common feature of said products is the packaging of granulated or crystalline de-icers in containers of polymeric or inert materials. Adhering to the protective sleeve, the deicing agent is very quickly dissolved by precipitation water, leaving a void in the bitumen layer that permits water to penetrate and other layers to be broken. This process significantly reduces the functionality and durability of the anti-icing treatment of the bitumen layer.

The present invention overcomes these drawbacks. The requirement for gradual dissolution of the additive is interrupted by the frosty synthetic aggregate, which is added to the bituminous vanes and pavements. Its essence is that it contains sodium chloride bonded with cured cement with granite. Synthetic aggregates embedded in the bituminous bituminous cover are gradually ground by traffic. The sodium chloride formed forms a 0 ° reduced freezing point with air humidity or water precipitation. The resulting solution prevents the formation of frost and ice, as well as the snowing of the road surface, enabling its better removal by mechanical means. The maximum thawing efficiency is achieved by synthetic stone in abrasive bitumen shroud covers in the temperature range from 0 ° C to -5 ° C. As a result of the improved isolation of the sodium chloride in the synthetic aggregate, there is a gradual dissolution of the additive only in the bituminous bitumen layer, thus retaining its flood properties until complete abrasion. Reducing the formation of frost to facilitate the removal of snow from the surface coating will be beneficial in minimizing the consumption of chemical spreading agents used in winter maintenance of communications.

The process for preparing synthetic aggregates of 40-70% of the acid chloride is explained in the following examples. Example 1

The composition of the mixture in the production of 1 tonne of synthetic aggregate at 40% NaCl content: troscortland cement 325 - ČSN 72 2122 400 kg sodium chloride 400 kg granite crumb 0—4 mm 200 kg pan water 200 kg Example 2

The composition of the mixture in the production of 1 tonne of synthetic aggregate at 50% sodium chloride content: troscortland cement 400 400 kg sodium chloride 500 kg granite crumb 0—4 mm 100 kg overflow water 200 kg Example 3

The composition of the mixture in the production of 1 tonne of synthetic aggregate at 70% sodium chloride content: troscortland cement 600 200 kg sodium chloride 700 kg granite crumb 0—4 mm 100 kg shed water 200 kg

Synthetic aggregates containing NaCl are produced by the same process as concrete mixtures using conventional technological equipment.

The invention can be used in the construction of popular layers of bituminous carcass and pavement coverings, especially in those cases where the safety of transport operations needs to be increased in winter conditions. The construction of bituminous roofing roads, especially highways and roads of the first and second class, as well as trails overflows comes to the fore. The structural composition and percentages of the synthetic aggregate in the bitumen mixture can be varied according to the climatic conditions and requirements of the users of the traffic communication. Example 4

Antifreeze synthetic aggregates form part of the natural aggregate in all the applied fractions in bituminous mixtures. From a number of possible recipes for the preparation of bituminous mixtures according to the requirements for the functionality and quality of roadway covers, we present the optimum composition of the bituminous mixture which was

Claims (1)

259 5 laboratory tested according to ČSN 73 6149 “Asphalt concrete for roadway covers”: limestone crumb 8–16 mm 22,30% granite crumb 4–8 mm 18,50% granite crumb 0–4 mm 34,20% limestone crush 3 70% sand 6,50% 96 6 antifreeze synthetic aggregate 8,60% honest asphalt petroleum A — 80 6,20% Laboratory tests of the bituminous mixture according to the mentioned recipe, carried out by an authorized organization, meet the criteria of ČSN 73 6149. ARTICLE Anti-freeze synthetic aggregates for the resilient layer of bituminous pavement coverings are characterized in that they contain sodium chloride 40 to 70 per cent per cent and granite crushed fraction 0 to 4 mm, 10 to 20 per cent solidly bonded with hardened troscortland cement 325 to 600 20 to 40 weight percent.