Gas quenching granulation is one of the most important modern methods utilized in molten steel slag (MSS) treatment, more positive and accurate simulated methods play a crucial role in guiding the whole gas quenching which dominate the stability, cementitious activity, magnetic separation of Magnetite and sensible heat recovery of MSS products, etc. However, the frequently used Volume of Fluid (VOF) methods can only predict the fragmentation process, but there appeared much deviation in identifying and calculating subsequent particle fragmentation and particle size distribution changes. To address these noticeable deviations, the VOF to DPM model is innovatively introduced to clarify the morphological spatial and temporal evolution for MSS by designing a transition from the continuous phase to the discrete phase for the divergent liquids. The DPM model is expert in tracking MSS particles in DPM form, and the motion, size changes, particle concentration and size distribution of divergent liquids were real-time counted and measured. Compared to the on-site particle size obtained using the air-quenching at Zhengfeng Steel Plant in China, the relative error between the two was less than 10%. The morphological spatial and temporal evolutions of MSS in the main body region, non-mutual adhesion region and particle field region were systematically studied from qualitative and quantitative aspects under different working conditions. Finally, scientific data was provided to optimize process parameters and improve granulation efficiency. These research findings provide valuable universal applicability in all the fields of gas quenching and fragmentation process and lay a theoretical foundation for subsequent strictly controlled granulated particles.

When employing the strut-and-tie modelling (STM) method in the conceptual design of reinforced concrete structures, a suitable strut-and-tie (ST) model indicating load transfer mechanisms first needs to be identified. Topology optimization (TO) methods have frequently been used for this purpose. However, although TO methods employing either a ground-structure or a continuum-based TO approach can be used, the performance and effectiveness of these two methods have not been systematically investigated and compared. To obtain a better understanding of the characteristics of both methods, a systematic comparison procedure is proposed to investigate the generation process and the resulting ST designs. Three aspects, relating to structural performance, economic issues, and method applicability are considered in the comparison, with six metrics formulated to quantify these aspects. Based on investigation of designs for three reinforced concrete elements incorporating typical discontinuity regions (two 2D cases and a 3D case), the performance of the two methods is assessed. It is found that both methods result in safe and efficient ST designs, with comparable structural performance, while some differences in terms of computation time and usability are observed.

Concrete, as the most widely used construction material, is associated with a high environmental impact. Within the present study, structural optimization is the method of choice to counter this issue. The entire process, from optimization, to design, experiments and numerical simulation is outlined. Embedded in the framework of a design competition (Concrete Girder Optimization Competition 2021), a bridge between structural engineering and mathematical optimization is demonstrated. Two design concepts for optimized concrete girders, one with internal and one with external reinforcement, yet both based on strut-and-tie modeling, were investigated. Within the boundaries of the competition, several conclusions can be drawn: The results indicate the importance of an adequate structural interpretation of topology optimization results to obtain satisfying structural performance. The environmental evaluation outlines that the reinforcement mass has a substantial share in the total Global Warming Potential. A successful numerical re-simulation of selected girders can serve as a modeling base for other researchers. Compared to a conventionally designed girder an increase in resource efficiency, measured by load-carrying capacity versus environmental impact, of more than 30% was achieved.