Experimental study on the performance of concrete linear cutting by high pressure water jet

High pressure water jet rock breakage technique is widely used in civil engineering, construction, mining and other fields due to its unique advantages. However, how to utilize water jets to break concrete efficiently has become an increasingly serious technical challenge. To reveal the characteristics of high-pressure water jet linear cutting of concrete, the influence of major cutting conditions and concrete properties on the cutting characteristics of concrete was first explored. Then, optical 3D profile scanning was used to explore the fracture morphology characteristics of concrete grooves, and based on scanning electron microscopy (SEM) technology, the micro damage mechanism of water jet cutting concrete was disclosed. Finally, a prediction model for depth and width of groove was developed using the method of regression analysis, followed by validation of the precision and robustness of the model. The research results indicate that the most effective method to increase the cutting depth is to enhance the jet pressure, and the most effective method to increase the cutting width is to enlarge the nozzle diameter; The irregularity of the groove is closely related to the heterogeneity of concrete materials, and coarse aggregates have a non-negligible effect on the characteristics of high-pressure water jet cutting concrete. The failure mechanism on the spalling surface of groove is mainly tensile failure caused by tensile stress, the failure mechanism on the lateral surface of groove is mainly shear failure caused by shear stress, and the failure mechanism on the bottom surface of groove is mainly compression-shear failure caused by compression-shear stress. The results of the study deepen the understanding of the characteristics of high-pressure water jet linear cutting concrete, and lay a theoretical foundation for the selection of parameters for efficient breaking of concrete by water jet.