Research on Cryogenic Properties of Different Fiber Asphalts and Mixtures

Abstract

From microstructure and technical performance of different fibers, the variation and influence of the different fibers’ properties and parameters on cryogenic properties of matrix asphalt and asphalt mixture were researched and evaluated through BBR and cryogenic trabecular bending tests. Research shows that: the addition of fibers makes the matrix asphalt’s low temperature creep stiffness S increases, creep slope m decreases, namely the matrix asphalt cryogenic flexibility and stress relaxation ability are weakened; cryogenic anti-cracking ability of asphalt mixture is significantly improved through adding different fibers, the order of improving effectiveness: Dolanit AS fiber> ARBOCEL lignin fiber> Basalt fiber; while asphalt content is constant, with the increase of fiber content, the mixture maximum bending strain, strength, deformation of mixture firstly increase and then decrease, the optimal asphalt content of asphalt mixtures and optimal fiber content of three fibers are identified according to the above three indicators’ maximum. Research points out the existed problems that are scope of application and evaluation indicators in BBR test of SHARP, optimal asphalt and fiber content are fully recommended, it provides scientific guidance and practical foundation for actual project.

Laboratory Study on Properties of Diatomite and Basalt Fiber Compound Modified Asphalt Mastic

“…SHRP generally requires ( =60 s) ≤ 300 MPa, ≥ 0.3 [26]. The smaller was, the better the cryogenic flexibility and nondeformability of modified asphalt mastic are; was higher, the asphalt creep stiffness was lower, the cryogenic stress relaxation ability of asphalt mastic was better, and the low temperature performance was better.…”

“…According to the reference method for the preparation of diatomite or fiber modified asphalt mastics [9,13,16,[25][26][27][28], the optimal content of diatomite was about 15% or that of basalt fiber is about 3%. Thus, in order to comprehensively analyze the performance of compound modified asphalt mastic with the change of the content of diatomite and basalt fiber, the contents of diatomite 5%, 10%, and 15% and the contents of basalt fiber 1%, 2%, 3%, and 4% were adopted and comprehensive trail design of diatomite and basalt fiber is performed.…”

“…Xiong et al [25] discovered that the high temperature performance of asphalt mastic could be improved by the basalt fiber addition. Liu et al [26] studied the various effects of three types of fibers on the low temperature performance of both asphalt mastic and asphalt mixture, by the BBR test and low temperature beam bending tests. The results displayed that at −10 ∘ C, compared to the neat asphalt mastic, basalt fiber modified asphalt mastic had lower creep stiffness ( ) and higher creep rate ( ) value, the low temperature performance of basalt fiber modified asphalt mastic was improved, and the low temperature crack resistance of basalt fiber asphalt mixture was also improved.…”

“…Due to the corresponding high strength and high resistance to water, acid, and alkali, along with the applicability to a wide range of temperatures and the good performance of durability, basalt fiber caused widespread concern in the research community [21]. In recent decades, basalt fiber has been widely utilized as a reinforcing modifier for the asphalt mastic and asphalt mixture performance [22][23][24][25][26]. Rong et al [22] added the chopped basalt fiber into the asphalt mixture discovering that the fatigue durability of the mixture increased significantly.…”

“…By the inorganic modified material utilization such as diatomite and basalt fiber as the modifier, not only the asphalt performance could be enhanced, but also the polymer modifier pollution to the environment could be avoided. Therefore, researchers have gradually paid attention to the utilization of inorganic modified materials [15][16][17][18][19][20][21][22][23][24][25][26].…”