Research on the modification of Polish-produced bitumens with waxes and additive complexes
Students Name: Sysoieva Yuliia Volodymyrivna
Qualification Level: magister
Speciality: Highways and Airfields
Institute: Institute of Civil Engineering and Building Systems
Mode of Study: part
Academic Year: 2022-2023 н.р.
Language of Defence: ukrainian
Abstract: Due to its natural properties, bitumen cannot fully meet the requirements of the work of coatings under the influence of modern traffic loads combined with adverse weather conditions. Bitumen is a thermoplastic material. Therefore, as the temperature rises, it softens and the tracks are formed on the surfaces in the summer under the influence of transport. At low temperatures, bitumen becomes hard and brittle. This leads to the formation of low-temperature cracks on the surfaces in winter. Due to low cohesive strength and lack of elastic properties of bitumen on coatings from prolonged transport loads at moderate and low temperatures, so-called "fatigue" cracks appear over time. Bitumen has a selective adhesion and does not adhere well to acidic rocks, which make up more than 90% of the stone materials used in road construction. Water peels off the bituminous film from the mineral surface. Unbound rubble is carried behind the wheels and potholes and pits appear on the pavements. Usually the occurrence and development of coating damage is a multifactorial process. In this case, various factors can enhance the effect of each other, accelerating the process of destruction. Thus, with weak adhesion of bitumen to the mineral material, the formation of cracks, as well as freezing of water in them provokes the formation of potholes, and increasing the number of cycles of "freezing-thawing" significantly accelerates this process. In order to increase the durability of coatings, it is necessary to change the behavior of bitumen. This can be achieved by modifying the bitumen with polymers and waxes. Modification of bitumen by polymers is more common. Today, 15 million tons of bitumen are used in road construction in the world, of which about 15% are modified with polymers. Among polymer modifiers, 70% are thermoelastoplasts based on copolymers of styrene and butadiene (SBS, SB, SBR, BR). The other 30% are terpolymers, SBR-type latexes, EVA-type thermoplastics and polyolefins. The high popularity of thermoplastic elastomers is due to the fact that they act in a complex way, giving bitumen at the same time increased strength and heat resistance, high elasticity (elasticity), improved low temperature characteristics. In turn, waxes act as energy-saving additives that allow to reduce the technological temperatures of bitumen use in asphalt concrete and clearly raise the temperature of softening of bitumen. Key words: bitumen, synthetic wax, polymer, complex additive, penetration, ductility. References 1. DSTU 4044:2019 Viscous petroleum road bitumens. Specifications 2. SOU 42.1-37641918-068:2017 Viscous road bitumens modified with wax-based additives. Specifications; 3. DSTU 9133:2021 Bitumen and bituminous binders. Road bitumens modified with additive complexes. Specifications 4. DSTU B V.2.7-135:2014 Road bitumens modified with polymers. Specifications. Change #1 5. SOU 45.2-00018112-036:2010 Building materials. Bitumens and bitumen polymers are liquid. Specifications