アスファルトの光による劣化に及ぼす膜厚，波長ならびにカーボンブラック添加の影響

Abstract

Focusing on sunlight that has severe effects on the degradation of asphalt pavement during service, this study examined the relationships between the film thickness of asphalt and the states of photodegradation. The results confirmed that thinner films had a higher modulus of elasticity, lower viscosity, and increased production of carbonyl groups, which is an indicator of oxidative degradation. The degree of degradation rapidly increased especially at thicknesses below 200 µm. The wavelength dependence of spectral photodegradation was also examined. Visual observations and the carbonyl index confirmed that ultraviolet irradiation in the range of 300 to 400 nm caused severe photodegradation of asphalt. Carbon black blocked light near the surface of the asphalt layer, where the damage caused by light is most severe. Addition of carbon black helps to prevent photodegradation by ultraviolet irradiation in the wavelength range of 300 to 400 nm.

Avaliação dos efeitos da radiação ultravioleta sobre propriedades reológicas de ligantes asfálticos modificados com PPA e copolímeros SBS e SBR

“…Diferentes pesquisadores arbitraram diferentes níveis de radiação, temperatura, tempo de ensaio, espessura do filme asfáltico, entre outras variáveis, não existindo padronização de procedimento. A técnica utilizada por Yamaguchi et al (2005), por exemplo, com o uso de lâmpadas de arco de xenônio corresponde à exposição ao ar livre por dois meses. Yamaguchi et al (2005) analisaram os efeitos da espessura do filme asfáltico, do comprimento de onda e da adição de negro de fumo ao ligante asfáltico.…”

“…A técnica utilizada por Yamaguchi et al (2005), por exemplo, com o uso de lâmpadas de arco de xenônio corresponde à exposição ao ar livre por dois meses. Yamaguchi et al (2005) analisaram os efeitos da espessura do filme asfáltico, do comprimento de onda e da adição de negro de fumo ao ligante asfáltico. Zeng et al (2015) estudaram a influência que as temperaturas geralmente arbitradas nestes testes têm sobre os resultados do envelhecimento UV, submetendo resíduos obtidos da estufa TFOT à radiação UV nas temperaturas de 30, 50 e 70ºC.…”

Study of Antiultraviolet Asphalt Modifiers and Their Antiageing Effects

“…Researchers adopted modifiers such as UV absorbents [14,15], LDHs [16][17][18], and nanomaterials [19] to improve the UV ageing resistance of asphalt. CB is an organic protective material with high absorbance to UV radiation, as a UV absorber has the potential to improve the UV ageing resistance and enhances the low temperature properties [20].…”

Physicochemical and pyrolysis properties of SARA fractions separated from asphalt binder

“…It is very important to investigate pyrolysis behaviors of asphalt materials [7]. To inhibit the pyrolyzation or combustion of asphalt binder, the usual method is to add the flame retardants into asphalt binder [8]. Considering environmental protection and safety, halogen-free and non-toxic flame retardants are added in the asphalt binder [9].…”