2024, Volume 70(74), Issue 2 (June), pp. 19 - 31

Unconventional and Environmentally Friendly Technique for Increasing the Strength of Building Materials Through CO₂-Absorbing and Trapping Inside

 LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania, lucianpaunescu16@gmail.com
ENIKÖ VOLCEANOV, Metallurgical Research Institute SA Bucharest, Romania, National University of Science and Technology POLITEHNICA Bucharest, Faculty of Engineering in Foreign Language, Bucharest, Romania
ADRIAN IOANA, National University of Science and Technology POLITEHNICA Bucharest, Faculty of Material Science and Engineering, Bucharest, Romania
BOGDAN VALENTIN PĂUNESCU, Consitrans SA Bucharest, Romania

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DOI: 10.5281/zenodo.13307940

Abstract
Self-compacting concrete using the iron dust waste ability to produce FeCO₃ by CO₂-absorbing/trapping and favouring the increase of concrete strength was designed and tested. Except for iron dust, other materials rich in silica and alumina (clay brick waste and metakaolin) or CaO-rich (calcium carbonate) and a catalyst (oxalic acid) were added to the mixture, forming a carbon-negative binding material. The paper originality was obtained by adopting new methods of intensive hardening the fresh concrete by its immersing or exposure to CO₂-enriched mediums, followed by free storage in air for 7 or 28 days for CO₂-absorbing (recommended by the inventor). The results showed that replacing the cement with 12.3% carbon-negative material, using usual ratios of sand, coarse aggregate, lignosulfonate, and water and also applying the concrete hardening variant through the two methods of immersing/exposure in CO₂-enriched mediums, concrete specimens with highest strength were made.
Keywords: carbon-negative, self-compacting concrete, iron dust, CO₂-absorbing, iron carbonate