Environmental Assessment of Demolition Tools Used in Townhouse Demolition: System Dynamics Modeling

Abstract

To accommodate population growth and migration to cities, many infrastructures have been demolished to build new residential units. Demolition processes cause various environmental problems globally and locally. The selection of methods used in demolition is crucial to reduce the long-term environmental impact. This study considers various combination tools used in townhouse demolition in Thailand, examines their environmental impacts, and suggests the combination of the tools to be used in the long term. The system dynamics (SD) modeling approach is utilized in this study to capture the changes in townhouse units, sizes, demolition tools, demolition time, and the work rates of tools and their effects on the environment. This approach has the capability to model complex relationships and examine long-term trends. Secondary data are employed to identify variables necessary for SD model development, such as the different sizes of townhouses in Thailand, the various types of demolition tools used in the construction industry, and environmental impacts from building demolition. The simulation results revealed that Combination 4, i.e., the use of demolition robots and hydraulic splitters, is the most effective combination to reduce the final impact percentage in the long term. Compared with the other three combinations, it generates the lowest CO2eq emissions, energy consumption, noise, dust, and heat. If demolition robots are not yet available, Combination 1 (i.e., the use of excavators, jackhammers, and flame-cutters) offers the lowest environmental impact in the long term. This study provides guidelines for decision-makers in the construction industry to make sustainable choices of demolition tools and techniques used for townhouse demolition to reduce long-term environmental impacts.