The Study On Mechanical Properties Of Simulating Component Of Concrete Projectwith MSWI As Fine Aggregate

With the continuous development of China’s urbanization process and the continuous improvement of people’s living standards,the output of municipal solid waste increased year by year,and has gradually become an environmental problem that needs to be solved urgently.As the volume of municipal solid waste incineration will be reduced by about 90%after incineration,many areas in China Introduced waste incineration treatment technology,the main solid products of waste incineration are divided into municipal solid waste incineration fly ash(MSWIA)and municipal solid waste incineration bottom slag(MSWIS).However,For the waste incineration that main treatment method for the later generated ash is landfill,which still needs to occupy a certain amount of land.On the other hand,with the rapid development of China’s construction industry,the demand for sand and gravel has soared,but with the national natural sand and gravel With the continuous increase of resource restriction and environmental protection,natural sand is facing the current situation of exhaustion or even no sand available,and the amount of natural sand mining will become increasingly difficult to meet the demand for sand in the market.The physical and chemical properties of municipal solid waste incineration slag were tested,and the results showed that: municipal solid waste incineration slag resembles natural sand in appearance,and its chemical composition is similar to cement clinker.Compared with natural sand,the shape of solid waste incineration slag particles Irregular,multi-angular,relatively flat particle gradation curve,large crushing index value,weak crush resistance,high moisture content of slag residue and dry water absorption rate of saturated surface,and toxic substance leaching test results show that all leaching indicators are It is far below the limit specified in the "Identification Standard for Hazardous Wastes"(GB 5085.3-2007).The results of rapid hydraulic orthogonal test show that: municipal solid waste incineration slag has a certain degree of hydraulicity,and the influence of different factors on the compressive strength of MSW incineration prism is in order,holding pressure>alkali content>autoclaved temperature>Autoclave time.The mechanical properties of engineering simulation components made of municipal solid waste incineration slag concrete under simulated construction conditions were tested.The test results of standard specimens made under the standard curing conditions of the laboratory show that the compressive strength and elastic modulus of engineering simulation components and standard specimens made under simulated construction conditions increase with the increase of age.The increase in sand ratio and water-binder ratio decreases.The highest compressive strengths of concrete engineering simulation components with 0%sand-replacement rate of ash and slag are 59.97 Mpa and 69.49 Mpa,respectively,which are5.97% and 1.54% lower than the compressive strengths of standard specimens made under standard laboratory curing conditions.When the contemporary sand rate is 50%,the engineering simulation components are 39.29 Mpa and 50.11 Mpa,and the compressive strengths of the standard specimens under the same conditions are 52.29 Mpa and 60.13 Mpa,respectively.Based on the previous test results,it is believed that the ash concrete in this area has moderate strength and relatively economical sand ratio when the contemporary sand ratio is 50%.It basically has the conditions to replace natural sand as concrete fine aggregate in concrete.It is recommended to control the sand replacement ratio when using it.Below50%.The microscopic pore structure of municipal solid waste incineration slag concrete was tested,combined with the mechanical performance test results,it was shown that the compressive strength of the ash concrete engineering simulation components and standard specimens produced under simulated construction conditions was negatively related to the air content,that is,the resistance Compressive strength decreases with the increase of air content;it is positively correlated with bubble specific area and bubble fractal dimension,that is,compressive strength increases with the increase of bubble specific area and fractal dimension.