## 1 Introduction  
As one of the most promising advanced geo-materials, concrete is widely used in geoengineering owing to its wide material availability, good workability, high strength, and low cost. The earliest use of concrete can be traced back to Roman times, when concrete consisted of aggregates, such as pieces of rocks, bricks, or ceramic titles, with gypsum and quicklime as binding materials, and volcanic dust [1]. In the 20 th century, concrete was extensively developed and became one of the most frequently used materials in construction [1]. However, this structure is susceptible to fire and dynamic loading. In recent years, the occurrence of fire, explosions, and earthquakes is frequently reported. Thus, it is imperative to study the thermal and dynamic behaviors of concrete with various high-temperature treatments. Nowadays, ultra-high-performance concrete (UHPC) technology is implemented to develop advanced concrete, which has superior mechanical propertiesand better durability than normal or traditional concrete. In addition, many concretes incorporate fibers to increase the tensile strength and crack resistance. [PERSON], [PERSON] et al. carried out an experiment with regard to the thermal performance of concrete, including the thermal conductivity, density, and specific heat capacity. It was found that the changes of concretes' thermal conductivities were mainly determined by the density of concrete [2; 3]. [PERSON], [PERSON] et al. regarded steel-fiber concrete as a compound material consisting of concrete matrix and fibers and simulated its thermal conductivity by using the finite-element method. They found that the addition of steel fiber significantly impacted the distributions of the heat flux and temperature. The effect of the fiber diameter on thermal conductivity is greater than that of the fiber length [3; 4]. [PERSON], [PERSON] et al. summarized the effects of high temperatures on the compressive strength, tensile strength, flexural strength, elastic modulus, peak strain, and stress-strain curves of steel-fiber concrete based on a large number of studies. Further, they proposed the constitutive models [5; 6]. [PERSON] et al. added glass fiber, polypropylene fiber, and polyacrylamide fiber into concrete and investigated its axial compression performance. His research found that the axial compressive strength of concrete increases first and then decreases while the peak strain increases continuously [7]. [PERSON] et al. added steel fiber into ultra-high-performance concrete (UHPC) and found that both the tensile strength and strain of UHPC are enhanced with the increase of the fiber content. Besides, the number of cracks on the surface of the specimen increased simultaneously [8]. [PERSON] et al. added glass fiber into recycled aggregate concrete and found that the bending resistance of concrete improved [9]. [PERSON] et al. found the fracture mechanical behaviors of concrete would be enhanced [10]. [PERSON] et al. (2003) [11] observed the strength change of concrete with and without the addition of fiber into concrete after it was exposed to high temperatures. They found that concrete with fiber effectively enhanced the fire resistance. At the same temperature, the strength of fiber concrete is greater than that of plain concrete. Many researchers have reached a similar conclusion in that the material strength, ductility, and impact resistance can be significantly improved by adding randomly distributed steel fibers into concrete [12; 13; 14; 15]. In the development and application of fiber-reinforced concrete, [PERSON] and [PERSON] (2002) [16] showed that the compressive strength of fiber-reinforced concrete decreases exponentially with the decrease of the density. [PERSON] et al. (2010) [17] conducted experimental research on the mechanical properties of ordinary concrete after the application of high temperatures. When the temperature did not exceed 300 \({}^{\circ}\)C, the compressive strength of high-temperature concrete changed little or even increased.