Study on the properties of artificial flood-prevention stone made by Yellow River silt

In the Yellow River Basin, the source of flood-prevention tone is scarce. The purpose of this study is to investigate the feasibility of producing a kind of artificial flood-prevention stone by using Yellow River silt via alkali-activated method. The effects of alkali dosage, slag content and curing age on the compressive strength of artificial flood-prevention stone were studied. The results showed that the specimen made from optimal mix proportion can meet the requirement of flood-prevention stone. The main product in alkali-activated process is C-S-H gel confirmed by microcosmic tests such as SEM/EDS, TG/DTG and so on. CaCO3 is generated by the carbonation of partial C-S-H gel and residual Ca(OH)2. C-S-H gel and CaCO3 have common contribution to strength. In addition, frost resistance of the artificial flood-prevention stone at the age of 90 days was evaluated by freeze-thaw cycle method. The porosity and pore size distribution were tested by Mercury intrusion porosimetry (MIP) to explicate the change before and after freeze-thaw cycle. As a whole, it is feasible to produce artificial flood-prevention stone by using the Yellow River silt.