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• The aging behavior of HSMB and LSMB under heat and UV were investigated. • The microstructure and chemical structure of HSMB and LSMB were analyzed. • The aging reaction rate and activation energy of LSMB and HSMB were studied. In this paper, the aging behavior of high dosage styrene–butadienestyrene (SBS) modified bitumen (HSMB) for waterproof materials and low dosage SBS modified bitumen (LSMB) for pavement were investigated. The effects of heat as well as ultraviolet-heat synergism on properties and chemical structure of HSMB and LSMB were evaluated by physical properties, fluorescence microscope (FM) and Fourier transform infrared spectroscopy (FTIR). The results showed that the change of softening point and low temperature flexibility of HSMB was much less than that of LSMB after heat aging, which indicated that the aging resistance of HSMB was better than that of LSMB. The physical properties changes of HSMB and LSMB after UV-heat synergism aging were much serious than that of HSMB and LSMB after heat aging. FM indicated that HSMB showed the network structure, and its structure was only partially destroyed after heat aging and completely destroyed after UV-heat synergism aging, while LSMB presented the sea-island structure, and the sea-island structure almost disappeared after aging. FTIR also showed that the change of carbonyl index (I C = O ), sulfoxide index (I S = O ) and butadiene double bonds index (I C = C ) of HSMB was smaller than that of LSMB after aging. The aging kinetic models of HSMB and LSMB were established by viscosity, the aging kinetic models showed that HSMB had lower aging reaction rate and larger activation energy than LSMB under the same aging condition, which meant that HSMB had better aging resistance. [ABSTRACT FROM AUTHOR]

• Self-healing capabilities of mortars under different temperatures were investigated. • Self-healing capabilities of mortars with microcapsules increased from 10 °C to 50 °C. • Crack of mortar with nano-SiO 2 /paraffin/PE wax microcapsule self-healed in 3 h at 50 °C. The ambient temperatures have significant effect on self-healing capabilities of concretes with microcapsules. Self-healing capabilities of mortars with different shell composition (paraffin, paraffin/PE wax and nano-SiO 2 /paraffin/PE wax) microcapsules containing toluene-di-isocyanate under the temperature of 10 °C, 30 °C, 50 °C and 60 °C were investigated in this paper. The compressive strength, chloride diffusion coefficient and pore size distribution of mortars containing microcapsules before and after self-healing were characterized by mechanical property test, rapid chloride migration test and nuclear magnetic resonance, respectively. The crack healing ratio of mortars during self-healing period were measured. The self-healing capabilities of mortars containing different microcapsules raised with the increase from 10 °C to 50 °C. Nevertheless, when the temperature reached 60 °C, the self-healing capability of the mortar containing paraffin microcapsules (AM1) decreased obviously, while the self-healing capabilities of the mortars containing paraffin/PE wax microcapsules (AM2) and nano-SiO 2 /paraffin/PE wax microcapsules (AM3) were almost unchanged. The self-healing capability of AM3 was superior to that of AM1 and AM2 at the same temperature. The compressive strength recovery rate, chloride diffusion coefficient recovery rate and harmful pores ratios of AM3 after pre-damaged at 50 °C for 7 d self-healing were 94.1%, 81.2% and 47.3%, respectively. When the ambient temperature reached 50 °C, the surface cracks of the mortar with three kinds of microcapsules could be completely self-healed in 5 h. However, when the temperature raised to 60 °C, the healing ratio of the crack in AM1 with a width of 0.4–0.5 mm decreased to 49.52% after 6 h self-healing. Meanwhile, the surface cracks of AM3 could be completely self-healed less than 3 h. [ABSTRACT FROM AUTHOR]