Development of a low carbon binder system based on metakaolin: Focus on corrosion inhibitor-intercalated layered double hydroxides

Abstract

In this work, MgO-CaO activated blends were produced by using metakaolin (MK). Roles of sodium nitrite (NaNO2) corrosion inhibitor on phase assemblance, micro-structure, and chloride binding of layered double hydroxides (LDH) in the systems were systematically studied. The results showed that the compressive strength in the middle and late stages were increased for 32.78% and 73.74% with the addition of CaO, and pore structure of the MgO-CaO-MK blends was optimized. After the addition of 5% NaNO2, NO2− anions were preferably intercalated into the layers of self-formed MgAl LDH and CaAl LDH. The chloride binding capacity of the samples was stronger than that of cement paste, which was attributed to the generation of more LDH by accelerating hydration of the system.