Garnet and steel shot have advantages and disadvantages in terms of cutting performance and economic efficiency as single abrasive materials for cutting rock and concrete using abrasive waterjet. However, the application of abrasive waterjet technology in construction sites is still limited due to the cutting performance and cost limitations of single abrasive. A new strategy is needed for effective field application of abrasive waterjet technology. In this study, mixed-abrasives, which are mixtures of garnet and steel shot at various mass ratios, were applied to abrasive waterjet cutting to address the limitations of garnet and steel shot, and optimize their advantages. The cutting characteristics of mixed-abrasives were experimentally evaluated, and cost analysis of granite and concrete was performed. Granite and concrete used in the cutting experiment are brittle materials with P-wave velocity of 5346 m/s and 3968 m/s, a uniaxial compressive strength of 236 MPa and 49 MPa, respectively. Mixed-abrasives were classified into fresh and recycled mixed-abrasives. The latter was categorized into reused and submerged conditions, and its cutting performance was evaluated using natural and oven-drying methods. To maximize cutting efficiency in terms of specific energy, it is desirable to apply an abrasive flow rate of approximately 11 g/s. By comprehensively considering cutting performance and economic efficiency, the optimal mixing ratio of garnet and steel shot was 50:50. The critical abrasive collect rates of granite and concrete were evaluated at 18–21 % and 28–37 %, respectively, depending on the abrasive cost ratio. In conclusion, it was confirmed that efficient cutting using mixed-abrasives is possible in terms of practical applications. In addition, the results of this study provide appropriate guidelines for method design considering market price fluctuations of abrasives. Therefore, it is expected that effective application of abrasive waterjet technology to the field is possible.

中文翻译：

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使用混合磨料提高花岗岩和混凝土的切割效率


石榴石和钢丸作为使用磨料水射流切割岩石和混凝土的单一研磨材料，在切割性能和经济效率方面各有优缺点。然而，由于单一磨料的切割性能和成本限制，磨料水射流技术在建筑工地上的应用仍然受到限制。需要一种新的策略来有效地现场应用磨料水射流技术。在这项研究中，混合磨料（石榴石和钢丸以各种质量比的混合物）应用于磨料水射流切割，以解决石榴石和钢丸的局限性，并优化其优势。对混合磨料的切割特性进行了实验评估，并对花岗岩和混凝土进行了成本分析。切割实验中使用的花岗岩和混凝土是脆性材料，P 波速度为 5346 m/s 和 3968 m/s，单轴抗压强度分别为 236 MPa 和 49 MPa。混合磨料分为新鲜混合磨料和回收混合磨料。后者分为再利用和浸没条件，使用自然和烘箱干燥方法评估其切割性能。为了最大限度地提高比能量方面的切割效率，最好施加大约 11 g/s 的磨料流速。综合考虑切削性能和经济效益，石榴石与钢丸的最佳混合比例为 50：50。根据磨料成本比率，花岗岩和混凝土的临界磨料收集率分别为 18-21 % 和 28-37 %。总之，证实了在实际应用中使用混合磨料进行高效切割是可能的。 此外，本研究的结果为考虑磨料市场价格波动的方法设计提供了适当的指导。因此，预计磨料水射流技术可以有效地应用于该领域。