Increasing the Weathering Resistance of Asphalt by Nanomodification

Abstract

The comparative analysis of quality indicators of asphalt concrete and methods of their control is discussed in the present article. Classifications of modifiers for improving the quality of asphalt concrete are given. Novel nanoscale modifier for the improvement the resistance to climatic influences on asphalt is developed. The nanomodifier is based on sols of iron hydroxide and silicic acid. Nanomodification consists in processing of the mineral component by nanomodifier; such processing leads to the formation of nanoscale layer on the surface of the mineral carrier. As a mineral carrier we propose a highly porous mineral diatomite powder. The influence of the nanomodifier on the weathering resistance of asphalt concrete is investigated. Resistance to climatic influences was estimated by loss of strength after one nominal year of exposure. To simulate environmental impacts, an environmental chamber was used. The specimens were held in conditions that correspond to combination of summer and winter climate. One nominal year of exposure included 10 cycles of variable water saturation-drying at a temperature of 20 °C and 10 cycles of freezing-thawing (freezing was performed at –20 °C, thawing – at 20 °C). Saturation-drying and freezing-thawing duration was four hours. It was shown that by means of nanomodification the weathering resistance can be increased by 36 %.