LAUSR

Abstract Soundless chemical demolition agents (SCDAs) provide a reliable alternative for demolishing concrete structures in densely populated areas. However, research on the demolition of reinforced concrete member using SCDAs has not been conducted in detail. In this study, 12 concrete beam segments with different parameters were prepared to investigate the method of demolishing concrete beam using SCDAs. The arrangement of single row holes perpendicular to the upper surface of the beam segment was adopted, and the stirrups at the top of the beam segment were cut off along the hole connecting line and its extension line before grouting. The results showed that owing to the defect caused by cutting stirrups, the crack on the upper surface of the beam segment developed at the cutting seam, and the vertical crack on the end surface of the beam segment was also formed at the cutting seam and extended to the bottom of the beam segment. Besides, the average volume expansion rate of SCDAs in all boreholes in the beam segment (i.e. volume expansion rate of SCDAs) was determined to evaluate the impacts of the concrete compressive strength, hole spacing, and hole diameter on the crushing effect. Finally, a new equation for computing the hole spacing was derived, considering the time after grouting, concrete compressive strength, hole diameter, tie reinforcement ratio, ambient temperature, and volume expansion rate of SCDAs. The solution obtained using the proposed equation was in good agreement with the experimental results and was expected to provide guidance for the engineering application of SCDAs.