Study on the effect of magnesium oxide activity on the curing effect of carbonization

Carbonation curing technology is an innovative technology proposed in recent years to treat weak soil with low carbon mixing. This technology uses magnesium oxide cement to mix with soil first, and then carbonizes it with CO₂ to achieve rapid strength improvement. The effect of MgO activity on carbonation curing was investigated in an indoor experiment and the microscopic mechanism was analyzed.

The results show that: the specimens can complete most of the carbonization in 3~6h, and reach stability after 24h carbonization, magnesium oxide activity has a significant effect on the carbonization curing effect, specifically the higher the magnesium oxide activity, the higher the carbonization degree of the specimens after carbonization, the more carbonization products, the smaller the pore volume, the denser the microstructure; the specimens after carbonization volume increased significantly, but the magnesium oxide activity has little effect on the volume change, three kinds of magnesium oxide The higher the activity of magnesium oxide, the greater the strength of the specimens, the strength of high activity magnesium oxide specimens carbonized for 6h can reach the standard maintenance 28d cement strength, stable strength of 2.5MPa, while the strength of low activity magnesium oxide specimens is only 0.5MPa; specimens carbonized and stable pH value of high activity specimens is 9.6, low activity specimens pH value is 9.0, are lower than the cement soil pH value.