Literature review of alkali-activated cementitious materials

This paper introduces the preparation technology and reaction mechanism of alkali-activated cementitious materials and then summarizes workability, mechanical properties, durability and high-temperature resistance of alkali-activated cementitious materials. It is found that the content of alkali activator and the modulus of sodium silicate are the key parameters affecting the setting time and fluidity of alkali-activated cementitious materials, of which the initial setting time is 13-183 min, the final setting time is 15-215 min and the fluidity is 133-230 mm. Different requirements of setting time and fluidity can be met by changing the content of alkali activator and modulus of sodium silicate. Alkali-activated cementitious materials have the performance of high strength and early strength, whose compressive strength can reach above 60 MPa at the age of 28 days, and the compressive strength at the age of 3 days can be up to more than 70% of the strength at the steady state. Alkali-activated cementitious materials can withstand at least 600-800℃, at which the compressive strength can remain above 60% of the strength at the normal temperature. Alkali-activated cementitious materials have excellent freeze-thaw resistance with frost-resisting grade of F300 at the lowest. Alkali-activated cementitious materials can resistant the acid corrosion due to the absence of products that are vulnerable to be corroded. Alkali-activated cementitious materials have excellent impermeability because of their dense structure of pores. Finally, aiming at the problems to be solved for the optimization and application of alkali-activated cementitious materials, such as the shrink and frost, this paper discusses the research trend of alkali-activated cementitious materials. © 2019, Editorial Office of Journal of Building Structures. All right reserved.