Influence of Activated Art Paper Sludge-Lime Ratio on Hydration Kinetics and Mechanical Behavior in Mixtures Cured at 20°C

This research study shows for the first time the hydration reaction of Activated Art Paper Sludge (AAPS)-lime mixtures cured at 20 degrees C. Two mixtures series were prepared using weight ratios of 3:1 and 1:1 for AAPS/lime. The kinetics of the hydration reaction was investigated by characterization techniques such as X-ray diffraction, thermo-gravimetrical and differential thermal analysis, Al-27 and Si-29 {H-1} magic angle spinning nuclear magnetic resonance. Results show higher quantity of hydrated phases formed with the increase of the AAPS/lime ratio (such as calcium silicates hydrates (C-S-H), hydrated tetracalcium monocarboaluminate (C(4)ACH(11)), and hydrotalcite-like phases), specially C-S-H exhibiting a major incorporation of Al3+ into silicate chains, increasing its medium chain length. It becomes demonstrated that mechanical performance of the studied mixtures will be directly influenced by all these parameters.