EVALUATION OF TEMPERATURE PARAMETERS OF LOWGRADE MODIFIED BITUMEN IN COMPARISON WITH HIGH GRADE BITUMEN

Abstract

To ensure the durability of asphalt concrete pavements, different grades of bitumen are used based on the climatic zone. However, bitumen is susceptible to aging due to the effects of temperature and solar radiation, which reduce its elasticity, adhesion, and deformation resistance. The purpose of this study is to analyze the effect of modifying the additive on the properties of low-grade bitumen and to compare the results with the characteristics of higher-grade bitumen. Tests were conducted on samples of bitumen grades M 50/70 and M 70/100. The results of softening point measurements indicate that samples of low-grade bitumen (Type 1) demonstrated stable values of 51.2 °C before modification and 68.6 °C after modification. The increase in the coefficients of dynamic viscosity for all samples remained within the maximum permissible value of 2.5. Flash point measurements exceeded the minimum permissible value for grades 50/70 and 70/100, with a recorded temperature of 230 °C. Although the brittleness temperature of the modified low-grade bitumen did not meet the requirements for higher grades, it was lower than the average brittleness values of some higher-grade bitumens. In conclusion, the addition of a modifier to low-grade bitumen does not negatively affect its temperature performance. Moreover, in certain cases, the modified bitumen outperforms higher-grade bitumen. The use of modifying additives with low grades of bitumen leads to the improvement of their exploitation properties under the influence of high temperatures. Hence, the potential application of additives helps to increase the service life of asphalt concrete in hot climatic conditions.