open access

https://hdl.handle.net/2115/97266

Natural carbonation boost for hardened cement fines by dripping technique

英語

Cement paste

2024-10

Elsevier

Cement & concrete composites

153

105731

This study proposes a dripping technique to improve the carbonation efficiency of hardened cement fine (HCF), which mimicked the binder part of waste concrete, sized between 0.6 mm and 1.18 mm under atmospheric CO2 concentration. After a 7-day carbonation using the dripping technique, the carbonation degree doubled compared with that at 85 % relative humidity (RH). This improved carbonation efficiency can be attributed to two factors: 1) The pores created during drying accelerate the infiltration of the solution, releasing more calcium ions; 2) The difference in calcium ion concentration between the surface aqueous film and pore solution causes calcium ions to migrate to the surface, accelerating the dissolution of calcium-bearing hydrates in the pore solution and releasing more calcium ions. Adjusting the dripping interval and drying conditions according to the particle size and amount of carbonatable calcium improves the carbonation efficiency. This strategic approach offers a practical means to contribute to the sustainable recycling of waste concrete.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

© <2024>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/

0958-9465