Issue 45

C. Huang et alii, Frattura ed Integrità Strutturale, 45 (2018) 108-120; DOI: 10.3221/IGF-ESIS.45.09 120 [6] Bandyopadhyaya, R., Das, A. and Basu, S., (2008). Numerical simulation of mechanical behaviour of asphalt mix, Construction and Building Materials, 22, pp. 1051-1058. [7] González, J.M., Miquel Canet, J., Oller, S. and Miró, R. (2007). A viscoplastic constitutive model with strain rate variables for asphalt mixtures-numerical simulation, Computational Materials Science, 38, pp. 543-560. [8] Guo, N. S., Zhao and Y. H. (2004). Study on creep performance of fiber reinforced asphalt concrete, Journal of China & Foreign Highway, 1, pp. 124-127. [9] Rahmani, E., Darabi, M. K., Abu Al-Rub, R. K., Kassem, E., Masad, E. A. and Little, D. N. (2013). Effect of confinement pressure on the nonlinear-viscoelastic response of asphalt concrete at high temperatures, Construction and Building Materials, 47, pp. 779-788. [10] Stastna, J., Zanzotto, L. and Vacin, O. J. (2003). Viscosity function in polymer-modified asphalts, Journal of Colloid and Interface Science, 259, pp. 200-207. [11] Sun L. and Zhu, Y. (2013). A serial two-stage viscoelastic–viscoplastic constitutive model with thermodynamical consistency for characterizing time-dependent deformation behavior of asphalt concrete mixtures, Construction and Building Materials, 40, pp. 584-595. [12] Ming, Z. H., Huang, W. and Qian, Z. D. (2007). Analysis on mechanics model of viscoelasticity behaviors for epoxy resin asphalt mixture, Journal of Highway and Transportation Research and Development, 24(6-9), pp. 34. [13] Ministry of Transport of the People's Republic of China, Standard test methods of bitumen and bituminous mixtures for highway engineering, JTG E20-2011, China Communications Press, Beijing, (2001). N OMENCLATURE t R Rheological time (s), t F = t  0  Creep test loading stress 1 E , 2 E Elastic modulus of elements 1 and 2 (MPa) 1  , 2  , 3  Viscosities of elements 3 ,4 and 5 (MPa·s)  2 2 E  (s -1 ) A, B The viscosity coefficient of element 4 0  Initial viscosity of element 5 a, b, c Viscosity coefficient of element 5 ( ) t  Creep strain ( ) t  Creep speed ( ) t  Acceleration of creep t  Solution of formula (13) , t R = t  T R Relaxation time (s): 1 1 /   T D Delay time (s): 2 2   a R Ratio of fiber length to diameter f P Fiber content: fiber to mineral mass ratio f V Volume ratio of fiber to mixture ( ) d t Creep trabecular mid-span deflection 2 R Square of correlation coefficient f  Fiber content characteristic parameter , f f a V R  =  ( , ) f t   The creep strain when characteristic parameter of fiber content is f  and time is t ( , ) f t   The Creep velocity when characteristic parameter of fiber content is f  and time is t 0  Loading stress (MPa)