Chloride binding in cement paste with calcined Mg-Al-CO3 LDH (CLDH) under different conditions

Abstract The chloride binding capacity of cement paste with Mg-Al CLDH, obtained through calcining a commercial LDH, is investigated under different concentration, environmental temperature, and concrete pore solution alkalinity conditions. transformation mechanism CLDH to Mg-Al-Cl LDH mainly explored by means X-ray diffraction (XRD) , Fourier-transform infrared spectroscopy (FT-IR) Differential thermogravimetric analysis (DTG). There appears be threshold concentration 1.0 mol/L for (6% incorporation) effectively enhancing the paste. Both lowering raising (>38 °C) temperature disadvantage in paste, amount bound at curing temperatures follows as 38 °C > 50 °C ? 20 °C > 3 °C. Higher also adverse both formation Friedel’s salt rehydration CLDH. With increasing pH from 12.5 13.5, improvement on became weaker. improves not only related excellent anions exchanging ability it but promotion it.