Mechanical Properties and Penetration Characteristics of Mudstone Slag-Based Waterproof Composites under Cyclic Loading

Abstract

In this study, ground polymers were prepared from mudstone and slag. NaOH and water glass were used as alkaline exciters and mine waste rock aggregate was used as the aggregate for mudstone slag-based waterproof composites (MSWCs). A series of laboratory tests, including a uniaxial compression test, uniaxial cyclic loading and unloading test, scanning electron microscope test, and rock penetration test were conducted for macrostructural and microstructural analysis. The effect of the coupling between the mudstone proportion and the number of uniaxial cyclic loading and unloading tests was investigated. The results showed that it is feasible to use mudstone and slag to synthesize geopolymers, and that MSWCs fulfil the conditions for use as a reconstituted water barrier. The permeability of MSWCs with the different mudstone proportions set in this study fulfils the requirement of being used as a material, and the permeability and uniaxial compressive strength of the MSWCs gradually decreased with increases in the mudstone proportion. Considering the UCS and permeability of the MSWCs, the optimal mudstone proportion of the MSWC is r = 0.6. In this test, cyclic loading and unloading times of 0, 25, 50, and 100 were set, and with an increase of cyclic loading and unloading times, the UCS of the MSWCs showed a tendency of increasing first and then decreasing. In the SEM test, with an increase of cyclic loading and unloading times, microfractures and pores appeared in the MSWCs, which led to a gradual increase in its permeability and a decrease in its waterproofness.