Alkali-Activated Materials with Pre-Treated Municipal Solid Waste Incinerator Bottom Ash
Applied Sciences
; 12(7):3535, 2022.
Article
in English
| ProQuest Central | ID: covidwho-1785490
ABSTRACT
This study presents the results of an experimental campaign on the use of municipal solid waste incinerator bottom ash (MIBA) and fly ash (FA) as precursors for the production of alkali-activated materials. MIBA was subjected to a pre-treatment stage in response to two issues high metallic aluminum content, which reacts in a high pH solution, releasing hydrogen;and low amorphous content of silica-, aluminum- and calcium-bearing phases, which translates into a limited formation of reaction products. The proposed pre-treatment stage oxidizes most of the metallic aluminum fraction and compensates for the low reactivity of the material via the formation of additional reactants. Different combinations of MIBA and FA were tried—mass-based ratios of 0/100, 25/75, 50/50, 75/25, and 100/0 for MIBA/FA. Two mix designs of the alkaline activator with sodium hydroxide and sodium silicate were evaluated by varying the Na2O/binder and SiO2/Na2O ratios. These mortars were tested in the fresh and hardened state. The results showed that the pre-treatment stage was effective at stabilizing the dimensional variation of MIBA. Despite the lower reactivity of MIBA, mortars with 50/50 of MIBA/FA presented a maximum 28-day compressive strength of 25.2 MPa, higher than the 5.7 MPa of mortars made with MIBA only.
Sciences: Comprehensive Works; alkali-activated materials; municipal solid waste incinerator bottom ash; fly ash; pre-treatment; Mechanical properties; Silicon dioxide; Aluminum; Hydrogen; Municipal solid waste; Incinerators; Pretreatment; Municipal waste management; Bottom ash; Caustic soda; Sodium hydroxide; Silica; COVID-19; Solid waste management; Pandemics; Reaction products; Sodium silicates; Mortars (material); Compressive strength; Portugal
Full text:
Available
Collection:
Databases of international organizations
Database:
ProQuest Central
Language:
English
Journal:
Applied Sciences
Year:
2022
Document Type:
Article
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