Research On Application Of Emulsified Asphalt Cold Recycling Technique In Freeway Overhual Project

In the process of freeway reconstruction, a large number of waste asphalt concrete will produced. During asphalt pavement reconstruction, using cold recycling technique can reduce exploition and using of new aggregate, avoid waste landfill covers and pollution, and reduce carbon emissions. So it has significant economic and environmental benefits.This paper is based on the overhaul engineering of Jingtai freeway Hexu south section. According to the characteristics of the freeway asphalt pavement reconstruction maintenance engineering, the application of emulsified asphalt cold recycling technique in freeway overhaul project is studied further. The research content of this paper mainly includes the following four aspects:Raw materials selection and performance test; Emulsified asphalt cold recycling mixture proportion design; Emulsified asphalt cold recycling mixture pavement performance study(the compressive modulus of resilience, low-temperature crack resistance, high-temperature stability, etc.); Cold recycling base course construction technology and quality control(graduation, splitting strength, compaction, etc).Based on a large number of laboratory test and actual construction data acquisition, the results are set out below in this paper. (1) According to the comparison between the density of specimen, Marshall stability and splitting strength, the twice compaction method is recommended.;(2) The critical strain energy density is used to evaluate the low-temperature crack resistance of emulsified asphalt cold recycling mixture. (3)The 20? compressive modulus of resilience of emulsified asphalt cold recycling mixture is 893.12MPa?928.23MPa and 15? compressive modulus of resilience is 949.03MPa-1001.97MPa, the temperature sensitivity is weak. (4) Analysis of cold recycling base course construction data, the quality control key points and quality acceptance criteria of cold recycling base course construction ia put forward. Research results lay a foundation for improving the cold recycling technique application system in highway maintenance engineering.