Experimental Study On Hybrid Model Of Construction Waste Management

With the gradual advancement of urbanization in China,the waste generated in construction activities has grown rapidly in recent years.The continuous increase in construction waste introduces a series of environmental and social problems.Due to limited landfill spaces,water pollution,energy consumption and harmful gas emissions,construction waste management has become an urgent issue for sustainable urban development.Firstly,through the analysis of the literature,the research gap has been found: it fails to take into consideration the uncontrollability and uncertainty of various construction waste processes in the construction waste management system.Secondly,this study develops the hybrid simulation system which integrated Agent-based Modeling,System Dynamics and Discrete-Event Simulation,based on the Discrete-Event Simulation Theory and System Dynamics Theory,the Complex System Theory and the Theory of Planned Behavior.Finally,taking the new-built residential project started in Shenzhen from January 2019 to December 2019 as a data resource,under the benchmark policy,two different processes(lean construction and traditional construction)are analyzed in terms of the processing time and economic and environmental costs.In the meantime,five policy simulations(the benchmark policy,source sorting,unit pricing policy,supervision and education policy and its combination policy)are also analyzed in terms of the processing time and economic and environmental costs.The effects of construction waste management under the five policies by comparing the simulation results,leading to the following conclusions:The waste disposal process based on lean construction can save time,reduce economic and environmental costs,and create benefit.Under the benchmark policy,the disposal of reusing,recycling and landfilling are in parallel.In terms of time,the process of lean construction saves about 461 minutes,which can reduce about 17% compared with that of traditional construction.In terms of economic costs,the process of lean construction saves RMB 370,400,which lowers by 1.36% compared with that of traditional construction.In terms of environmental benefit,the process of lean construction creates RMB 2.86 million,which can increase by 10.65% compared with that of traditional construction.To minimize the negative impacts of construction waste pollution on the environment,policy effects are ranked as follows: combination policy > source sorting policy > supervision and education policy > unit pricing policy.The combination policy integrates the advantages of the source sorting policy,the supervision and education policy and unit charging policy.In terms of environmental benefit,the combination policy creates RMB 5.80 million,which can increase by 24.12% compared with that of the benchmark policy.In terms of economic costs,the combination policy increases by RMB 0.45 million,which increases by 1.67% with the benchmark policy.Under the combination policy,the disposal costs increase by RMB 0.45 million,while the environmental benefit increases by RMB 5.80 million.In summary,this study dynamically regulates the construction waste management policy based on the hybrid simulation.And it provides a scientific basis for relevant management departments or other stakeholders to control the flow of construction waste,formulate corresponding policies and help the illegal dumping situation.