When the forced two-horizontal shaft mixer is used to mix concrete, the mixing drum and the mixing components are subjected to random loads of the mixture. Structural static analysis usually ignores the randomness of the load, resulting in a large calculation error. Based on the EDEM software, this paper simulates the mixing process of the mixture, obtains the random load data of the mixture on the mixing drum and the mixing parts, and describes the variation law of the random load with a probability distribution, establishes the stress-strength interference reliability model of the mixer structure, and Monte Carlo simulation method is used to solve the structural reliability of the mixer. The results show that the load distribution of the mixing arm is the same as the mixing blade, the load distribution follows the gamma distribution, and the mixing shaft also follows the gamma distribution; the load distribution of the mixing drum follows the normal distribution. After calculation, the above load probability distribution and its intensity distribution do not interfere, and the structural reliability of the mixer meets the requirements, which can ensure the safe operation of the mixer. This method solves the reliability calculation error caused by random loads.

Taking foamed bitumen preparation equipment as the research object, aiming at the shortcomings and shortcomings of traditional failure mode and effect analysis (FMEA) method, this paper proposes a method to improve FMEA based on intuitionistic fuzzy. This method converts N expert language variables into corresponding intuitionistic fuzzy numbers to represent the failure mode and risk factor weight evaluation information. Combined with intuitionistic fuzzy weighted geometric operators and improved Hamming distance, the traditional FMEA method is improved to determine the bubble Risk order of failure mode of asphalt preparation plant. The results show that: asphalt pipe blockage, asphalt tank cracking and tapered rod end fracture are the three highest failure modes for foamed asphalt preparation equipment.

The FMEA method is a bottom-up method, and the FTA method is a top-down method. This paper proposes to combine the two methods, using the complementarity of the FMEA method and the FTA method, and targeting the innovative product- The six subsystems of the bubble device perform fault analysis, grasp the key parts of the fault, and propose corresponding solutions based on a comprehensive analysis of the fault. The analysis results show that the failures of the asphalt foaming device mainly occur before and during the asphalt foaming. The FMEA table reflects that the RPN value of the two failure factors of the blockage of the asphalt pipeline and the blockage of the water nozzle is the largest. The three failure factors with the highest severity level (SER) are heater damage, motor damage and PLC control device failure.

Foamed asphalt recycling technology can effectively recover waste asphalt pavement materials and achieve the sustainable utilization of resources. This technology’s core equipment is asphalt foaming equipment. Since the asphalt foaming device’s fault data are uncertain, this work proposes a method for evaluating the device’s reliability, combining triangular intuitionistic fuzzy numbers, trapezoidal intuitionistic fuzzy numbers, and expert knowledge. Using the proposed evaluation method, the failure probability of the asphalt foaming device and the importance of the bottom event were calculated. The obtained model results were found to be consistent with the actual collected data, verifying the reliability and validity of the model. Furthermore, the asphalt viscosity is one of the key factors affecting the asphalt foaming recycling technology. In this work, the influence of different viscosities on the asphalt foaming mechanism was investigated using a theoretical analysis. Then, a computational fluid dynamics (CFD) analysis method was employed to simulate the different viscosity asphalt foaming processes, aiming to identify the most suitable one for the production of high-quality foam asphalt in the foaming asphalt viscosity range. Finally, experiments were carried out to verify the results of the analysis. The results show that the asphalt foaming device’s failure probability was around 7.512 × 10−2, and the best foaming asphalt viscosity was in the range of 0.3~0.5 Pa·s.

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