Preparation And Performance Optimization Of Ultra-low Density Foam Concrete Filling Material For Mining

In the field of coal mines,due to the reintegration and division of coal resources,coal mines after integration usually have problems such as blurred mining processes and chaotic geological data.Mining face frequently crossing old lanes or empty lanes has become a major technical problem in coal mining.The use of grouting filling material to fill waste goafs,empty lanes and old lanes is the main method to solve coal mine safety accidents such as roof fall and gas outburst caused by inadequate management of old lanes.The quality of grouting filling material is a key link that affects the quality of grouting filling engineering.The research goal of this article is to prepare a new type of ultra-low density foam concrete filling material for mining,which is mainly to optimize the dry density,compressive strength,fluidity,and pouring height of ultra-low density foam concrete.In order to increase the porosity of foamed concrete and reduce the dry density of foamed concrete,it is usually necessary to add a large amount of foam to the concrete slurry.However,when the amount of foam in the slurry is high,the gelling material between the cells will be reduced,resulting in the occurrence of a large number of string holes and rotten pores,thereby reducing the fluidity and compressive strength of the foam concrete.When the situation is serious,the foamed concrete will also settle,collapse and bubble in the macro.Therefore,in order to improve the compressive strength and the fluidity and volume stability of foamed concrete,it is necessary to optimize the performance of foamed concrete slurry.This subject mainly used single factor rotation test method and orthogonal test method to study the effects of foam content,modified silicone resin polyether and polypropylene fiber on the dry density,fluidity and compressive strength of foamed concrete,and the effect of mineral admixture I and mineral admixture II on volume stability and compressive strength of ultra-low density foam concrete,and the mechanism of mineral admixture I and II on the compressive strength and volume stability of foamed concrete is analyzed from the mechanism.Finally,the optimal blending ratio of the various internal admixtures and additives for the preparation of the foam concrete in accordance with the research goals was determined.The paper has 40 figures,18 tables,and 94 references.