## 1 Introduction  
With the increase of the traffic volume in recent years, neat asphalt mixtures have been difficult to cover all the required specifications in the design of asphalt pavements [1]. Therefore, more and more modifiers and reinforced materials are used to improve the performance of neat asphalt mixtures, such as styrene-butadiene-styrene (SBS), diatomite, and basalt fibers. Some researchers have pointed out that the basalt fibers and diatomic reinforced asphalt mixture (DBFAM), as well as SBS modified asphalt mixture (SBSAM), have excellent mechanical properties [2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12]. [PERSON] et al. [2] pointed out that the addition of diatomite significantly decreased the equivalent brittle point of asphalt, thus diatomite could greatly improve the low-temperature performance of asphalt. [PERSON] et al. [3] studied the low-temperature performance of diatomite modified asphalt mixtures by static creep tests, thermal stress restraint tests, and thermal conductivity tests, and the results showed that the low-temperature performance of diatomite modified asphalt mixture is better than that of neat asphalt mixture. [PERSON] et al. [5] claimed that the addition of diatomite could improve the water damage resistance and the permanent deformation resistance of neat asphalt mixtures, but could not improve the crack and fatigue resistance of asphalt mixtures. [PERSON] et al. [13] introduced that the stress could be dispersed and the development of cracks of asphalt could be suppressed by a stable three-dimensional network made by basalt fibers in the asphalt. [PERSON] et al. [14; 15] found that the low-temperature cracking resistance of asphalt mixtures could be improved by adding basalt fibers, but this improvement was different by the variation of basalt fibers content. [PERSON] et al. [16] pointed out that the bending performance at low temperature and fatigue property of asphalt mixtures under the complicated environment such as chloride erosion and freezing-thawing environment could be improved by adding moderate basalt fibers content. To further and comprehensively improve the properties of asphalt mixtures, some researchers proposed diatomite and basalt fibers were used simultaneously to enhance the performance of asphalt mixtures. [PERSON] et al. [17; 18] reported that the basalt fibers and diatomite compound reinforced asphalt mastic and asphalt mixture exhibited excellent high- and low-temperature performance and fatigue resistance. According to the multi-objection orthogonal experimental design, the optimal proportions of basalt fibers and diatomite in asphalt mixtures were 0.32% and 14%, respectively [19]. [PERSON] et al. [20] pointed to that basalt fibers could significantly improve the low-temperature performance of diatomite modified asphalt mixture, and can prolong the fatigue life of diatomite modified asphalt mixture. In addition, SBS, as an organic modifier, is often used to improve the engineering performance of asphalt mixtures. Some studies indicated that the SBS modifier could significantly reinforce the cracking resistance and the rutting resistance of asphalt and asphalt mixtures, and reduce the temperature and moisture susceptibility of asphalt and asphalt mixtures [6; 7; 9; 10; 11; 12; 21]. [PERSON] et al. [22] investigated the viscoelastic properties of SBS modified asphalt binder using the Burgers model, and the results showed that the addition of SBS could improve the viscoelastic properties of the binder. [PERSON] et al. [1] studied that the fatigue resistance of SBS modified asphalt using the energy approach and the viscoelastic continuum damage method, and the results showed that the fatigue resistance of asphalt could be significantly enhanced by adding SBS. It can be found from the above that DBFAM and SBSAM have outstanding high- and low-temperature properties, yet less work has been done to study the creep and relaxation properties of DBFAM and SBSAM.