Experimental study on proportioning and properties of cemented filling material with a large mass ratio of construction demolition waste

Abstract

Supply of cheap and abundant raw materials is a key factor in reducing the cost of cemented filling materials. To solve this problems of the high cost of cemented filling materials and insufficient sources of raw materials, an experimental study on cemented filling material with a large mass ratio of construction demolition waste was performed. A large amount of recycled aggregate of construction demolition waste was added to cemented material to prepare a high concentration slurry, from which the influences of aggregate/cement mass ratio, admixture/cement mass ratio, water/solid mass ratio, recycled aggregate gradation and mud content of recycled aggregate on slump, setting time and compressive strength of cemented filling material with a large mass ratio of construction demolition waste were analysed via the orthogonal test method and regression equation analysis. Finally, an industrial formula for cemented filling material with a large mass ratio of construction demolition waste was determined, and the mechanical and microscopic properties were analysed. The results indicate that the industrial formula with an aggregate/cement mass ratio of 3.0, an admixture/cement mass ratio of 1.5%, a water/solid mass ratio of 0.35, a recycled aggregate gradation of 40:30:15:15, a mud content of recycled aggregate of 0ཞ4% and a mass ratio of construction demolition waste to solid material of 75% exhibits the properties of rapid strength growth and high residual strength, and can be applied in underground coal mines conditions.