Investigation of self-healing properties of dense-graded asphalt mixture containing microcapsule

To study the self-healing performance of the asphalt mixture with microcapsules and its influencing factors, this paper uses high-pressure water penetration test to evaluate the selfhealing performance of the microcapsule asphalt mixture, and studies the influence of microcapsule content, mixture properties (mixture type, maximum nominal particle size, porosity, asphalt type and amount) and use environment (self-healing temperature and time, moisture) on the self-healing performance. The results showed that as the amount of microcapsules increased, the self-healing effect increased first and then decreased. The optimal amount of microcapsules was determined to be 6%. In terms of the properties of the mixture, the self-healing effect of the suspension dense gradation is better than that of the skeleton dense type, and the matrix asphalt is better than the modified asphalt. The smaller the nominal maximum particle size and porosity are, the better the self-healing effect is. In external conditions, the temperature is conducive to the self-healing of the mixture within a certain range. The selfhealing performance increases nonlinearly with the healing time, and the moisture is not conducive to the self-healing of the asphalt mixture cracks.