The potentiality on alkali activation of volcanic tuff with calcium-based materials, fly ash, and their mixtures as additives were comprehensively investigated in this study. Several characterization strategies have been employed for mechanism exploration. CaO and fly ash (FA) brought about more dramatic responses than CaSO 4 and alkaline activator on activating the volcanic tuff-based geopolymer, which was relatively stable under the wet-dry alternated conditions. The symmetrical stretching vibration of Si–O–T (T = Al or Si) was right-shifted to the band at approximately 1036 cm −1 , implying the incorporation of Ca into Si–O–T. FA accompanying with CaO enhanced the polycondensation, gelation, and hardening of geopolymer. However, too many quartz balls brought into geopolymer paste by an excessive amount of fly ash deteriorated the cementing quality and reduced the mechanical strengths. This work contributes to the module usage of volcanic tuff in the construction industries and supplies an innovative method in activating geopolymerization.
The supply of blast furnace slag (BFS) for alkali-activated materials (AAMs) has declined due to increased scrap recycling and BFS usage in cement industry. Sustainable supplementary precursors are urgently needed to ensure the progress of AAMs. This study treated municipal solid waste incineration (MSWI) fly ash (MFA) with accelerated carbonation (AC) to convert the waste material into suitable precursors. MFA exhibited strong CO 2 capture due to the presence of slaked lime, with calcite content rising by 67 % after 6-h of AC. Heavy metal leaching was significantly reduced, with Cu and Pb leachate decreasing by 53.1 % and 73.5 %, respectively. AAM mixtures with 0–50 wt% carbonated MFA (CMFA) were tested. While CMFA slowed early structuration and altered fresh mixture properties, 10 wt% CMFA achieved comparable 28-day strength to the reference, and heavy metal leachate from hardened mortars met environmental standards. Results have confirmed CMFA is a viable supplementary precursor for AAMs.
危险品化学品经营许可证（带存储）