Influence of MGO expansive agent on behavior of cement pastes and concrete

الملخص EN

An MgO expansive agent was prepared by different calcined systems.

The effect of calcined systems on the hydration and expansion of the MgO expansive agent was studied and the best calcined system was obtained.

The properties of MgO expansive agent, which was prepared at the best calcined system, were researched.

The results showed that the MgO expansive agent prepared at 1000°C for 1 hour, with the particle diameter 45 to 150 μm delayed autoclave expansion.

The autoclave test which was used to evaluate the soundness of concrete on the basis of expansion rate or strength changes can better express the soundness of concrete with MgO expansive agent.

The expansion rate of MgO expansive agent was fast within 3 to 14 days and became slow after 120 days, the larger pores decreased, and the overall structure became compact in the presence of MgO expansive agent.