Page 96 - Abstract book - TJSSF-2020

Thailand – Japan Student Science Fair 2020 (TJ-SSF 2020)
“Seeding Innovations through Fostering Thailand – Japan Youth Friendship”

Concrete Carbonation and Our Lives

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Hane Moe , Fujii Kaho
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Advisors: Takuya Ohata , Tzuzuki Keita , Eguchi Keiko , Kaneko Michiko

1 National Institute of Technology Toyota College

Abstract

We have been learning construction materials. The reinforced concrete is cheap and of high durability.
It is used in many things such as skyscraper, civil structure, but the concrete causes corrosion problems
in reinforced steel. The concrete is important for our lives so we believe that we must solve the problem.
We studied and experimented concrete carbonation (Ca(OH)2+CO2→CaCO3+H2O). Concrete,
CH3COOH and phenolphthalein solution were prepared.

We created concrete as follows.
1: Set water, cement, fine aggregate and coarse aggregate (Tabel.1)
2: Mixed them and let the air bubbles out. (Use iron mold for compressive strength test, Toro boat)
3: Consolidated concrete.
4: Cut concrete (A) and put in CH3COOH.
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Tabel.1: Mix proportion of concrete (1m )

W/C s/a Water Cement Fine Coarse AE
aggregate aggregate entraining
agent
3
3
3
3
3
(%) (%) (kg/m ) (kg/m ) (kg/m ) (kg/m ) (g/m )
0.52 45.7 194 373 778 965 0
The concrete was put in CH3COOH for a week. CH3COOH pH is 3, originally concrete pH is 14. The
carbonation depth of concrete was 30mm. The right picture (C) shows normal concrete, but the middle
picture (B) shows carbonated concrete. Concrete carbonation proceed quickly, so it is clear to check
concrete carbonation frequently.

Keywords: Concrete, Concrete Carbonation, Corrosion in Reinforced Steel

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