Abstract
Coarse aggregate is the major part of asphalt mixture, and plays an essential role in mechanical performance of pavement structure. However, the use of poor-quality coarse recycled aggregate (CRA) reduces the strength and stability of the aggregate skeleton. It is a challenge to predict accurately the influence of CRA on the performance of asphalt mixture. In this study, both a uniaxial compression test and a direct tensile test were carried out to evaluate the failure strength of asphalt concrete with four CRA content. The discrete element method (DEM) was applied to simulate the specimen of asphalt concrete considering the distribution and properties of CRA. The results showed that temperature and loading rate have a significant influence on failure strength, especially when the CRA content was more than 20%. With the increase of CRA content, both cohesion force and internal friction angle were gradually weakened. The proposed model can be used to predict the failure strength of asphalt mixture, since both experimental and simulated results had a high consistency and repeatability. With the decrease of CRA strength, the nominal cohesion force of the specimen decreased, while the internal friction angle increased.
Highlights
The recycling of construction and demolition (C&D) materials have attracted much attention in pavement engineering because of its huge environmental and economic benefits [1]
The experimental results with different coarse recycled aggregate (CRA) content indirectly reflect the changes of the above microscopic properties, while the discrete element method (DEM) provides an effective tool to further predict the effect of CRA properties on the failure strength of asphalt mixture
The experimental results showed that the effect of loading rate on the failure strength of the CRA asphalt mixture was substantial, especially when the CRA content was more than 20% and at high temperature
Summary
The recycling of construction and demolition (C&D) materials have attracted much attention in pavement engineering because of its huge environmental and economic benefits [1]. Since pavement construction consumes a large amount of sand and gravel, the potential utilization rate of C&D waste is very high for pavement materials. This is a sustainable way to solve the over exploitation of mine resources, by crushing C&D waste into recycled aggregate (RA) instead of natural aggregate. The recycling of C&D waste in pavement engineering has broad application prospects and economic value
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