Experimental Study On Engineering Properties Of Municipal Solid Waste Incineration Bottom Ash In Wuhan

China's rapid economic development in recent decades has caused many disturbing problems,such as garbage siege.Faced with the accumulation of domestic garbage,China is gradually changing its waste disposal methods.Waste incineration has gradually become a popular waste disposal method.However,it also produces considerable incineration residues.Landfilling is a direct way for domestic waste incineration bottom ash disposal,which is widely used at home and abroad.In the increasingly tense land scarcity around the city,how to deal with the incineration bottom ash has received increasing attention,and investigating its beneficial reuse is of great significance.The main research work and results of this thesis are as follows:1.By the SEM analysis of the microscopic morphology of the bottom ash,its formation mechanism was further explained.From the perspective of particle gradation,specific gravity,liquidity and plasticity,the significant physical parameters were provided to identify the classification of BA,and to clarify the differences between the bottom ash and the traditional soils.The results showed that the surface of BA is prone to wear effortlessly and adhere to aggregated or granular crystals with obvious internal pores.The experimental study found that BA is classified as a poor coarse-grained sandy soil with a lower plasticity and a higher specific gravity.2.The engineering characteristics of the MSWI bottom ash that had been produced from a Waste-to-Energy plant in Wuhan were investigated by conducting a series of laboratory experiments.Moreover,comparing with the measured values of mechanical properties of traditional building materials,the recommended values of important mechanical parameters were provided to consider as the reference of the practical bottom ash re-utilization.The results indicated that the compaction and permeability of BA is similar to sand or gravel.Under the consolidation test,BA is also identified as a medium compressive soil with a low compressive deformation and certain consolidation.The direct shear test confirmed that BA has a higher shear strength,its fraction angle measured is similar with sand.In terms of bearing capacity of BA,the CBR of BA ranged from 70 to 170 with an increase of a compaction time from 35 to 98,revealing that the bearing capacity of BA meets the requirement of road fills.3.The main chemical and mineral components of the bottom ash were analyzed by WD-XRF and XRD.From the perspective of the environmental impact of BA,the leaching characteristics was evaluated by the indoor leaching toxicity test and the determination of heavy metal concentrations.The experimental result showed that the concentrations of heavy metal elements did not exceed the regulatory threshold value in accordance with GB 5085.3-2007.The work and conclusions of this thesis may have very important guiding significance to the practical road engineering for the feasibility of MSWI bottom ash in Wuhan regions.