Study on the Mechanical Properties and Design Parameters of Floor Slabs Waste Subgrade Filler

Abstract

In recent years, there have been more and more studies on the use of construction and demolition waste (CDW) as subgrade filler. The physical performance indexes of a single material of floor slabs waste (FSW) are studied, which meet the requirements of subgrade specification. From the perspective of construction quality control, it is proposed that when FSW is used as subgrade filler, the compaction thickness and the maximum allowable particle size should be controlled according to different layers, and the gradation of subgrade filler is evaluated by using the nonuniformity coefficient (Cu) and curvature coefficient (Cc). The compaction test of FSW shows that the maximum dry density and optimum moisture content of different gradations do not change much. The crushing value under the freeze-thaw cycle is proposed to evaluate the frost resistance of FSW. The crushing value of FSW after water absorption and frost heaving changes a little. The CBR and resilience modulus tests were carried out on the FSW such that the results show that they have a good relationship and the relevant expressions under different compaction degrees are fitted. When performing on-site compaction testing, it is proposed that the upper roadbed adopts the sand replacement method according to the different layers of the FSW subgrade and the settlement discrepancy method should be adopted for other parts. Through laboratory tests and construction field detective, the quality control requirements, road performance indexes, and design indexes of FSW materials are put forward.