A method for controlling the blasting effect of reinforced concrete columns

In the field of reinforced concrete structure demolition, efficient and safe methods are crucial for engineering progress and space optimization. Drilling and blasting, a method that precisely controls the collapse of columns by managing the explosion process, is commonly used. This creates conditions for subsequent construction or space optimization. However, research on the effect of detonation delay time on the blasting effect in the demolition of reinforced concrete columns remains limited. This paper combines the ABAQUS's CDP constitutive model and the CONWEP explosion method to establish a numerical model of the blasting effect on reinforced concrete columns, validated by drilling and blasting experiments. The findings demonstrate the model's feasibility, with numerical simulations showing satisfactory consistency with experimental results in terms of hoop damage and the volume affected by the explosion, with an error margin of 17% for the blasted column volume. The study further reveals that detonation delay time significantly affects the blasting effect, which can increase tensile damage in the far area of column blasting holes and reduce the flying speed of concrete in the intermediate area between two blasting holes. To ensure operational effectiveness, it is recommended to carefully adjust the detonation delay time during reinforced concrete column blasting operations, ensuring it remains within the optimal threshold dictated by specific conditions. For the operational parameters stipulated in this study, the optimal value is constrained not to exceed 0.8 ms. This study provides important guidance and practical application value for reinforced concrete column blasting demolition operations.