Nano-treatment of Autoclaved Aerated Concrete Waste and Its Usage in Cleaner Building Materials

Abstract

Autoclaved aerated concrete waste (AACW) was used as a raw material to prepare nucleation seed for acceleration of Portland cement. Nano AACW seed with median particle size of 324 nm was prepared by wet grinding method. Both the electrical conductivity and pH value of nano AACW suspension were obviously improved. Both the setting times and intensity of the main hydration heat peak were promoted by nano AACW, indicating the possibility of AACW suspension as nucleation seed. The early age compressive strength before 3 days was also clearly improved by nano AACW, with no negative effect on the late age strength. Furthermore, the reduced CH content with dosage of nano AACW indicates that nano AACW not only plays a role of nucleation seed in cement hydration, but also has a certain pozzolanic reaction.

Keywords

autoclaved aerated concrete waste / construction and demolition waste / wet grinding / nano technology / nucleation seed