Research On Construction Waste Recycling Based On Evolutionary Game Theory

The level of urbanization in China has been continuously improved in recent years,which causes the urban population continues to increase and the city scale expands unceasingly with a lot of new construction projects and the old city renovation.For example,the new building of residential houses in downtown is expected to reach 5.3 billion square meters during the “13th Five-Year Plan” period.Somewhere behind the improvement of people's living standard is the consumption of natural resources and a large number of construction waste generated.At present,the disposal methods of construction waste in most parts of our country are still rough,mainly including open storage and landfill.This huge amount of construction waste which can't be properly handled will further aggravate the current problem of "Waste Siege",not only lead to the abuse of natural resources,but also a threat to urban sustainable development over time.There is a general agreement among researchers that recycling is an effective way to solve the problem of construction waste disposal in China.This type of recycling,which turns construction waste into green building materials,can not only avoid pollution,reduce landfills,but also improve the efficiency of resource utilization.On the whole practice of our country,however,the overall level of construction waste recycling is low.Researches show that cooperation among construction and demolition enterprises,comprehensive utilization enterprises,building materials production enterprises,government and other stakeholders is an important condition for the improvement of construction waste recycling.However,there is no effective cooperation among these stakeholders in practice.So this paper is based on the construction enterprises and building materials production enterprises which are the major stakeholders in construction waste recycling.By establishing evolutionary game based models,the evolutionary decision making process and stable strategies between construction enterprises and building materials production enterprises in situation with or without government intervention,as well as factors promoting construction waste recycling are analyzed firstly in this paper.It also studies the government subsidy and punishment measures promoting construction waste recycling quantitatively.Secondly,the decision making process and stable strategies between the two groups are simulated under different initial states and changes in parameters.Finally,combined with the results of the analysis and simulation,a staged promotion mechanism of construction waste recycling is put forward,which is expected to be the decision-making basis for improving the overall effect of the construction waste recycling.The results show that when there is no government intervention,whether the cooperation between the two groups can be formed depends on the initial profit of these enterprises not carrying out construction waste recycling,benefit allocation coefficient and the total cost of recycling,and the level of construction enterprises' efforts in waste sorting.In the case of government intervention,it has different subsidy and punishment measures to promote the cooperation according to different situations in construction waste recycling.The findings also suggest that the policy intensity that recycling cooperation needed when subsidies and punishment are combined is lower than it required when implement it separately,which means it helps to reduce the reliance on government subsidies for the development of construction waste recycling on one hand,on the other hand,the punishment for enterprises not doing waste recycling seems more reasonable.Further,the corresponding promotion mechanism for cooperation is put forward based on the different situations in construction waste recycling development.In situation 1 of the waste recycling development,cooperation between construction enterprises and building materials production enterprises has not been formed yet,it still has difficulty in developing construction waste recycling.Thus,the government should take the leading role and enhance the intensity of subsidy and punishment policies in order to reduce the cost of recycling and cover the differential profits.In situation 2 of the waste recycling,economic benefits of the waste recycling seem to increase.It relies mainly on leading enterprises of waste recycling and encouragement of the government.The policy intensity can be reduced and mainly for lowering the cost of the risks in construction waste recycling.In situation 3 of the waste recycling,it relies on the leadership of the market and the assistance of the government,which means promoting the reasonable allocation of the benefit from construction waste recycling among stakeholders.The compensation is further reduced,and the government should mainly focus on the supervision and punishment policies in this situation.This study also finds that the continuous developing of laws and regulations,enhancing the supervision of relevant departments,also increasing the acceptance of the recycled products are needed to guarantee the implementation of the promotion mechanism for construction waste recycling.