Study On The Preparation And Properties Of Sound-absorbing Cerasmite From Construction And Demolition Waste Renewable Material

With the rapid development of construction of urbanization in our country,the volume of construction and demolition(C&D)waste is also increasing rapidly year by year,which results in a series problems such as serious ecological environment and waste of resources,while we are also facing a serious situation in which C&D waste surround the cities.However,noise pollution is another environmental issue that we are facing.Especially with the constant improvement of urban rail transit network,the mileages of urban metro,light-rail and high-speed railway are increasing year by year.Noise pollution caused by rail transit has become one of the important pollution sources affecting the living quality of residents.In order to reduce the problem of the rail transit noise pollution and achieve the recycling of C&D waste.The paper develops sound-absorbing ceramsite from C&D waste renewable material through the non-sintering preparation process,and achieve the utilization and recycling of C&D waste.And then,a kind of sound-absorption ceramsite concrete is prepared by using the self-made C&D waste ceramsite as the main aggregate,can be used as a new type of sound-absorbing and noise-reducing material for cement-based ceramsite concrete,which is a waste-conserving and energy-saving material,and can be applied to control the rail traffic noise.The research contents and main achievements of this paper are as follows:(1)Based on the single factor ratio and multi-factor orthogonal test methods,the best proportion of the non-sintering sound-absorbing ceramsite from the C&D waste renewable material was researched and developed.In order to get the best ratio for preparing ceramsite,selecting the cylinder pressure and bulk density of ceramsite as reference indexes,selecting the C&D waste,fly ash and cement to conduct the orthogonal experiment with the amount of activator and binder determined,and analyzing the impacts of each raw material on the performance of ceramsite.Finally,the best materials ratio for the sound-absorbing ceramsite of C&D waste renewable material is 23.7%of C&D waste,53%of fly ash,11.8%of cement,11%of activator,0.5%of binder.The results show that the influence order on the reference indexes of ceramsite is:cement>C&D waste>fly ash.(2)After obtaining the best material ratio for preparing ceramsite,and in order to evaluate the properties of the prepared ceramsite,the basic physical properties of the ceramsite were tested by using the small batch of ceramsite production.The results show that the cylinder pressure of ceramsite is about 6.4?7.5MPa,the bulk density and apparent density are 900kg/m~3and 1639kg/m~3,the porosity and water absorption of ceramsite are45.6%and 17.5%,respectively,and the basic physical performance indexes meet the standard requirements of the artificial high strength lightweight aggregate.(3)In order to develop a new type of waste energy-saving cement-based ceramsite concrete sound-absorbing noise reduction materials,through the analysis of the properties of acoustic ceramic materials,through the analysis of the characteristics of the acoustic ceramsite concrete,and finally,selecting the target porosity,water-cement ratio and the grading of ceramsite to conduct the sound-absorbing ceramsite concrete orthogonal experiment by choosing the volumetric method,and also combination the sound-absorbing properties of the material by using standing wave tube method,finally,the optimized mix proportion of sound-absorbing ceramsite concrete material is 20%of target porosity,water-cement(W/C)ratio is 0.28,while the ceramsite for type I.Under this parameters conditions,the effective porosity of sound-absorbing ceramsite concrete material is 23.8%,the average sound absorption coefficient is 0.545,the compressive strength is 12.45MPa and dry apparent density is 1362kg/m~3.The experiment also shows that taking the average sound absorption coefficient and compressive strength of the sound-absorbing ceramsite concrete material as reference indexes,the influence order on the reference indexes of sound-absorbing material is:target porosity>ceramsite type>W/C ratio.(4)In order to obtain the real acoustic noise reduction effect of the sound-absorbing ceramic materials,meet the acoustic environment of the practical application of the material,and to make up the shortcomings of the standing wave tube method on the sound absorption properties test of sound absorbing materials.The test results show that the average sound absorption coefficient of cement-based sound absorbing ceramsite concrete material is 0.74 and the noise reduction coefficient(NRC)is 0.80,which is an ideal sound absorbing and noise reducing material.