Effect of cornstalk ash on the microstructure of cement-based material under sulfate attack

Cornstalk ash is one of the most abundant, renewable and green supplementary cementitious materials, which is an effective approach to decrease the amount of cement in concrete structures for reducing CO2 emission. In this paper, the influence of mechanical properties and microstructure of the mortar with different proportion of corn stalk ash under sulfate attack are investigated, and it can provide necessary theoretical basis and practical guiding significance for practical engineering. A series of measurements are used to characterize the effect of the corn straw ash of cement hydration products, such as XRD, hydration heat and SEM. It is concluded that corn stalk ash can partly replace cement without reducing the compressive strength and enhance the compressive strength under sulfate attack, the data of TG shows that the content of the calcium dioxide is obviously decreased with corn straw ash.