Study On Preparation And Performance Optimization Of Foam Concrete For Mining Filling Materials

China has a long history of utilizing coal resources.It is currently the world's largest coal producer and importer.For a long time,coal has been one of the most important energy sources in our country.After entering the 21st century,my country has carried out reasonable layout and planning of coal mining,and integrated the nation's disorderly and disorderly mining and illegal mining.However,due to the serious chaos and disorderly mining in the early stage,the integrated coal resources still have problems such as chaotic geological data and management difficulties.The consequence is often that the goaf and roof are easily damaged during the re-mining process,which poses a huge threat to the safety of re-mining and production,and is likely to cause casualties and property losses.In the actual production process of most coal mines,grouting and filling methods are usually used to solve coal mine safety accidents such as waste of resources,roof fall,and gas outburst caused by the destruction of goafs and roofs.In order to solve this problem,from the perspective of fully recovering coal resources and solving the safety problem of not fully returning to the mine,this paper proposes the research topic of preparation and performance optimization of foamed concrete for mining filling materials,and conducts detailed research.The final research goal of this subject is to prepare a new type of foamed concrete filling material for mines that is low-cost,energy-saving and environmentally friendly,has superior mechanical properties and is suitable for coal mine site use.At present,the foam concrete filling materials mainly have the shortcoming of insufficient mechanical properties.Aiming at the common problems of this kind,this paper mainly conducts the research on the optimization of the strength of the foam concrete from the perspective of improving the mechanical properties.From the perspective of cost saving,it is necessary to ensure that the foamed concrete has a sufficient expansion ratio.The test set the target value of the dry density of the finished filling material between 250?350kg/m~3 target value,so the water-cement ratio of the foamed concrete and The foam content is set at a higher level When the finished foamed concrete filling material has a lower dry density,its compressive performance will also be at a lower level.In severe cases,it will also show settlement or even collapse on the macroscopic level,and its performance will directly affect the quality of filling works.For this reason,it is necessary to improve the compressive strength of the prepared foam concrete and optimize its performance to improve its stability.While improving the strength,the experiment of this subject studied the influence of cement,metakaolin and silica fume on the basic properties of foamed concrete,and obtained an optimal ratio.Next,on the basis of this optimal ratio,polypropylene fiber and polycarboxylic acid water reducer were added to study the optimization effect of these two dosages on the compressive strength performance of foam concrete filling materials.Finally,foam stabilizer and Na-based bentonite are used to optimize the volume stability of the foam concrete filling material.