## 1 Introduction  
With the growth of civilian development, it is necessary to demolish either potentially hazardous or no longer used buildings. Most civil structures are reinforced concrete (RC) structures, and blasting-based demolition is preferred in their destruction applications due to the economical and time-efficient natures, compared with conventional mechanical reconstruction methods. However, the blasting-based demolition may involve numerous significant risks, including the potential of causing damage to surrounding buildings and the possibility of incomplete destruction, which may result in fatalities or significantly raise the cost. As a result, considerable effort is required to optimally design the demolition process. Optimization of structural behavior when applying the blasting is essential for a successful demolition process, and a numerical method can be one of the most effective tools because it can provide a substantial amount of useful information (e.g., stress, strain, velocity, displacement, etc.) and enables the identifying the significant parameters affecting the progressive destruction of RC structures under various conditions. As a result, numerous studies have been conducted to simulate the destruction of the RC structure to determine the optimal demolition scenario in the event of an actual collapse. A continuum-based approach has been widely adopted to reproduce RC structures' destruction process using finite element method (FEM) software. Most RC structural models in FEM software use the constraint approach with a linear edge reinforcement model. The constraint method models the rebar and concrete separately, and the reinforcing effect of the RC structure is reproduced by constraining the movements of adjacent components when they overlap. In the FEM RC structural model, the failure process of the RC structure resulting in the collapse is expressed by deleting or fracturing the main load-bearing structural components. The frame structure-blasting demolition processes was simulated using FEM implemented in LS-DYNA to investigate the mechanism of collapse and its applicability to practical demolition modeling [1]. In [1], weakening of the structural part were compared for the cases with and without explosive loading (i.e., structural part deletion), and the results indicate that explosive blasting applied on the cut site is more comparable to the examination of the actual demolition. Meanwhile, FEM implemented in ANSYS software was also used to model the explosive demolition of old cylindrical silos [2]. This study provided guidance for pre-weakening cylindrical silos prior to blast destruction based on the findings obtained by structural analysis and numerical simulation. Due to the large number of reinforcement bars to represent in RC structures, efforts to simplify the reinforcement bars in the modeling of RC structure demolitions were also presented [3]. In [3], a simple structural analysis model was used to verify the proposed numerical approach in comparison to the experimental outcome. However, the simplified numerical modeling for demolition had limitations in simulating RC concrete fracture and fragmentation. The study for considering the effect of the size of FEM elements in structural blasting demolition simulation using FEM in LS-DYNA can be found [4]. To investigate the element size effect on the response of overall RC structure, the FEM models with element sizes of 20 cm and 40 cm were developed in this work. They demonstrated that the coarse element model reduced the structure's collapse time due to an exaggeration of the structural impact effect, resulting in more severe structural damage than the fine element model. Most significantly, most continuum-based demolition simulations have used the element deletion approach to model RC concrete fracture processes. In [5], it was found that the simulation of material failures process via element erosion did result in the elimination of almost whole the structure, reducing the accuracy and reliability of the final result.