Abstract: n order to improve the accuracy of fatigue performance evaluation and optimal design of emulsified asphalt cold recycled mixture, the effect of cement content, emulsified asphalt content and RAP content on fatigue performance of cold recycled mixture under various stress ratio were studied by orthogonal test design. Based on BP neural network model and genetic algorithm, materials parameter were optimized and the correlation between materials content and stress level was illustrated. Then the anti-cracking mechanism of cold recycled mixture was revealed according to SEM test and elemental analysis. The results showed that the significance of materials content influencing fatigue performance under various stress ratio was ranked differently, and the fatigue performance all existed a peak as materials content increased under high stress level. The proportion of 1.53% cement, 3.56% emulsified asphalt and 78.31% RAP was recommend by genetic optimization results. Abundant hydration products like C3S and C2S were found positioning in the interfacial crack between asphalt and aggregate, where the content of Ca/Si was as high as 78.84% that enhanced the interfacial strength.
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