Effect of layered double hydroxides addition on the ageing and self-healing properties of asphalt binder

In this paper, the effects of Layered Double Hydroxides (LDHs) incorporation on the ageing resistance and self-healing properties of asphalt binder were studied. Matrix asphalt (MA) and LDHs modified asphalt (LMA) binders were aged by short-term thermal oxidation and ultraviolet ageing and their ageing performance was characterized through the analysis of the SARA fractions and temperature sweep test. Frequency sweep test and capillary flow test were conducted to characterize the fluidity of the asphalts, and fatigue life recovery test was used to characterize the asphalt self-healing properties. The main results indicate that under the same ageing conditions, the light component contents of LDHs modified asphalt are higher than that of matrix asphalt and the complex modulus increment of LMAis lower than that of matrix asphalt. It means that LDHs modified asphalt has better anti-ageing performance. Besides, LDHs modified asphalt has higher fluidity and lower self-healing threshold temperature than matrix asphalt binder under the same ageing conditions, indicating that the incorporation of LDHs can effectively retard the reduction of asphalt flow capacity due to ageing. It was also found that asphalt binder containing LDHs had better self-healing potential due to the improvement of the ageing resistance. It was concluded that the addition of LDHs can effectively improve the ageing resistance and self-healing properties of asphalt binder.