Natural asphalt has been produced from Pitch Lake since 1850. Nowadays, Lake Asphalt of Trinidad and Tobago, Ltd. openly produces this material which is transported to Germany to be processed by Carl Ungewitter Trinidad Lake Asphalt GmbH & Co. Due to vast variety of forms of the additions they may be used in ll of the technological modes of production at asphalt-concrete plants, for example, JSC “Tatavtodor” used NAF-501 and Epure Z 0/8 additions. For more information about the additions please visit http://www.ungewitter.de/

The key property of natural asphalt as an addition to “synthesized” is that it slows down the oxidation in the adhesive, which was proved many times by tests in rolling thin film oven (RTFOT). The average loss of fusing temperature of the natural asphalt after processing at 163 °C with hot air is 3 °C only, whereas same compounded asphalt without the addition loses about 6-7 °C. In 2016 specialists from JSC “Tatavtodor” constructed two sites with open-porous asphalt-concrete surface, using the addition at one of them. In two year’s time we can state that addition of natural asphalt improves cohesive characteristics of the adhesive thus improving performance characteristics of the surface.

Application of NAF-501 modification of natural asphalt allows construction of asphalt-concrete surfaces with stabilizing agents. Sites made of macadam-and-mastics asphalt (grade 10), open-porous asphalt ПА-15, and porous mastic asphalt-concrete ПМА-10 (a new asphalt type) were constructed with addition of this modification. Epure Z 0/8 addition was used in 2018 in construction of test sites at the entrance to production base of Suburban branch (Laishevsky district, Usady settlement)/ the sites were constructed with asphalt-concrete types prepared according to SP-19 mix design (100 gyrations). These mixes feature high residual porosity up to 7% in the road surface, and less asphalt ratio in the mix.

The results of studies of the adhesives, conducted by JSC “Tatavtodor”, makes it clear that application of natural asphalts and other organic and synthetic additions enhances performance characteristics of asphalt-concrete surfaces, including their durability.

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