Concrete crushing based on the high-voltage pulse discharge technology

Abstract

High-voltage pulse discharge (HVPD) technology has a broad prospect in concrete crushing. The model of concrete beam sections is established by ANSYS/LS-DYNA finite element software. The shock wave, caused by the electrohydraulic effect of HVPD with 50 kJ energy, is equivalent to an explosive blast shock load. The analysis of concrete beam sections throughout loading was carried out. The section size of each beam segment is width × height = 400 mm × 800 mm, and the lengths of beams are: 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm and 1100 mm respectively. The influence of aperture and spacing of holes on the crushing effect of the concrete beam segment was investigated. Two holes were drilled vertically on the wide and length surface of the concrete beam section, and the corresponding drilling spacing for each length of beam section is 200 mm, 300 mm, 400 mm, 500 mm, 600 mm and 700 mm respectively. The depth of holes in each beam is 450 mm, and the diameters of holes are 30 mm, 50 mm and 70 mm respectively. The analysis results show that with the increase of the hole diameter and the decrease of the hole spacing, the crushing effect of the concrete beam section is gradually enhanced. Depending on the crushing effect of the beam section, the optimal layout scheme is determined that the hole diameter is 50 mm, the hole spacing is 400 mm and the hole end (edge) spacing is 250 mm. A scheme is proposed to set multiple rows of holes in the width direction for the beams which have a large size. And the maximum row spacing of holes is the same as the maximum spacing of holes. The models of beam segments with width of 900 mm, 1300 mm and 1700 mm are established to verify the rationality of the arrangement scheme. Of the beam, the section size is 800 mm × 900 mm, the hole diameter is 50 mm, the hole spacing is 400 mm, and the hole row spacing is 400 mm. The analysis results show that the concrete beam segment is effectively crushed under the multi-row hole layout scheme.