Get started
Work

Durability properties of concrete with alternative fine aggregate from woodfired fluidized bed boilers

Year: 2026
Type: article
Abstract: Durability is one of the main factors that has made concrete the most used construction material in the world. Studies have shown bottom ash from the combustion of wood in fluidized bed boilers to be a viable replacement for natural sand in concrete regarding mechanical properties, but with limited research on its effect on durability. Durability of mortar and concrete mixes with partial sand substitution at 0% 25% and 50% were tested. Three different ash samples were applied: two samples from a circulating fluidized bed (CFB) boiler from different times in the combustion cycle, and one from a bubbling fluidized bed (BFB) boiler. Concrete cylinders were used for testing freeze-thaw resistance and chloride penetration resistance, while mortar prisms were subjected to an accelerated alkali-silica reactivity (ASR) test. For the frost tests, a spalling of ≤0.1% was recorded for the 0% replacement and 25% CFB ash, giving them a ‘very good’ frost resistance. ASR tests showed an expansion of ∼0.05% for the reference casting and CFB mixes with 25% replacement, whereas the BFB ash caused high levels of ASR expansion of ∼1% after 20 weeks. The ASR test was complemented by microscopy analysis on fluorescent epoxy impregnated thin sections. Ash particles were also characterized by SEM-EDX, to further elucidate the cause of the results presented in the paper. The results showed that wood bottom ash can achieve durability properties similar to natural sand, given the particles are confirmed to not be alkali silica reactive.
DOI: 10.1016/j.jobe.2026.117212
Language: English
Open Access status: hybrid
Estimated APC paid: $3,940
OpenAlex ID: W7204252815
FWCI:
Cites: 35
Cited by:
Related to: 10