A steel fiber-reinforced recycled concrete (SFRRC) is a porous material, and its macromechanical properties are affected by its microstructure. To elucidate the change rules and internal mechanisms of the mechanical properties of SFRRCs, the mechanical properties and failure modes of SFRRCs were studied at different water–cement ratio, replacement rate of recycled concrete aggregate (RCA), and steel fiber content. Moreover, the microstructures of the interface transition zones (ITZ) of the SFRRC specimens were tested by scanning electron microscopy and mercury intrusion, and the effect of the microscopic pore structure on the macromechanical properties of SFRRC was analyzed. The research results showed that an appropriate amount of steel fibers could reduce the size and number of cracks in the ITZ and improve the pore structure of an SFRRC. Based on the fractal dimension, porosity and other factors, the quantitative relationship between the macromechanical properties and microscopic pore structure parameters of SFRRCs was established.

In order to promote and apply the structures of the recycled concrete block (RCB) masonry, the thermal and mechanical properties of the recycled concrete specimens were tested in this study. The RCB can meet load‐bearing and seismic requirements and was prepared through experiments. Concurrently, the mechanical property experiment was conducted on the RCB masonry, and then its failure process and mode were discussed. In addition, a thermal property test was completed on the RCB wall, and the difference in the thermal properties of single‐row hole, three‐row hole, and solid blocks was analyzed by theoretical calculations. The results indicated that the mechanical properties of the RCB masonry were basically the same as those of the natural concrete block masonry, and they have good compressive stability. The calculation formulas of the compressive and shear strengths of the natural concrete block masonry are applicable to the RCB masonry. The RCB masonry containing three rows of holes owns more outstanding thermal property than natural concrete block masonry and satisfies the requirements for related codes.

The coal crusher generates large vibrations when crushing coal blocks, which can affect the equipment itself, as well as the safety of the structure. In order to study the dynamic characteristics of coal crusher, a finite element model of the coal crusher chamber in the Shangluo power plant was built by using ABAQUS. Firstly, modal and harmonic response analyses were conducted, and the comparison shows that the numerical results are basically in accordance with the test results. Then, shock absorption research was performed using a parametric analysis that included the stiffness and position of the spring vibration isolator, the mass, and material of the vibration-isolation platform. Finally, the dynamic coefficient of a coal crusher was discussed. The results showed that, compared with the stiffness of the spring vibration isolator, the mass of the vibration-isolation platform had more influence on the vibration displacement of the coal crusher. To achieve better vibration isolation, the concrete platform is suggested, and the eccentricity of the spring vibration isolator should not exceed 5%. When static design method is adopted to calculate the bearing capacity of the supporting structure subjected to the dynamic load of the coal crusher, the dynamic coefficient of a coal crusher is suggested as 1.5.