Study On The Influence Of Municipal Waste Incineration Fly Ash In Cement-Stabilized Rubble Base Mixture

With development and improvement of China’s economy and people’s living conditions,the waste generated is also increasing.Among them,landfill is the most common treatment.However,the landfill does not only waste and consume a lot of land resources,but also need continuous observation and treatment for the subsequent impact of landfill on groundwater and surrounding environment,which virtually increases the economic burden of the state and taxpayers.Therefore,a new treatment method for garbage is imminent.In this study,fly ash,the product of MSW incineration,was added into cement stabilized macadam base mixture,so as to realize the resource recycling of fly ash.In this thesis,the common c-b-3 gradation in engineering is adopted.Different proportions of fly ash and washed fly ash are added into the cement stabilized macadam mixture with 4% cement content,and the best content is selected by 7 d unconfined compressive strength.Aiming at the most common base diseases in highway engineering,the road performance tests such as water stability,erosion resistance,wet dry cycle and freeze-thaw cycle were carried out.The porosity of the samples before and after freeze-thaw cycle was scanned by using CT scanning and MATLAB software.Finally,the economic and environmental evaluation of fly ash /water washing ash was analyzed.The specific research contents of this paper are as follows:(1)The fly ash / water washed ash is mixed into the mixture with a certain proportion instead of fine aggregate,and the optimal mixing amount of them under the design gradation is determined by 7-day unconfined compressive strength.The experimental results of compressive modulus of resilience and unconfined compressive strength at this content further verify the effectiveness of the content;(2)Four kinds of road performance tests,including water stability test,wet dry cycle test,erosion resistance test and freeze-thaw cycle test,were carried out for the three types of specimens.The test results show that the addition of fly ash / water washing ash makes the cement stabilized macadam mixture have no significant negative effect in the first two tests,and the erosion resistance is strengthened.However,in the freeze-thaw cycle,the mechanical properties of the original sample fly ash decrease significantly;(3)The internal voids of three kinds of specimens before and after freeze-thaw were obtained by CT scanning and MATLAB software.By contrast,it is found that the addition of fly ash / water washing ash fills the internal voids of the specimens,which makes the specimens have better macro mechanical properties.After freeze-thaw,the mechanical strength of the specimens decreases sharply with the increase of the voids of fly ash;(4)The economy and environmental protection of the mixture with fly ash are analyzed.The results show that the economic benefit of the mixture is obvious,and it can meet the national environmental protection requirements.This paper studies the influence of incineration fly ash on the mechanical properties and road performance of cement stabilized macadam mixture,and analyzes the economic and environmental protection.It shows that if it is used in highway construction,it has good economic and environmental benefits.