This paper investigates the effect of the hydrothermal synthesis conditions on the formation of xonotlite and the change of xonotlite-based lightweight material's (Xo_AAC) physical properties under carbonation. Experiments included: quantitative X-ray diffraction, scanning electron microscopy, thermogravimetric differential thermal analysis, drying shrinkage, carbonation shrinkage, compressive strength, mercury intrusion porosimetry, thermomechanical analysis, solid-state nuclear magnetic resonance, water vapor absorption isothermal, and nanoindentation test. The pure crystalline xonotlite was formed at 230 degrees C for the autoclaving time of more than 18 h and at short heating time (2 h). The drying shrinkage and dimensional change rate of Xo_AAC were smaller than that of autoclaved aerated concrete (AAC). The compressive strength of Xo_AAC was slightly increased after carbonation. The carbonation of Xo_AAC occurred more quickly than AAC containing silicone oil. However, the amount of carbonation shrinkage was almost the same for both Xo_AAC and AAC in a later period.
Influence of hydrothermal synthesis conditions and carbonation on physical properties of xonotlite-based lightweight material
