| dc.description.abstract | In order to respond to the world-changing green trend, energy conservation and carbon reduction, and sustainable development policies, the cement industry has become a key research project on how to consume the collected carbon dioxide. In this regard, we designed three different sizes of cylindrical specimens (namely Ф15×30 cm, Ф10×20 cm, and Ф5×10 cm) with a target strength of 21MPa, and three sizes of cubic specimens (namely 15x15x15cm, 30x30x30cm, and 40x40x40cm). The prepared samples were placed in an environment with a carbon dioxide concentration of 50% and a pressure of 2 bar, and the carbon dioxide curing of the concrete was carried out with three pressurization times of 1hr, 3hr, and 6hr. The purpose of this study is to investigate the compressive strength, size effect, chloride ion penetration and freeze-thaw cycles of cylindrical and cubic specimens after carbon curing.
From the experimental results, it can be found that the overall compressive strength of the cylindrical specimen after carbon curing for 3 hours is increased by about 10 to 30%, while the part of the cubic specimen is increased by about 0 to 15% under the condition of curing time of 6 hours. Ultrasonic testing has shown that carbon-cured concrete has the good quality established by the existing specifications in the early days. In the part of the size effect, the carbon size magnification factor of the cubic specimen is about 1.15, which is obviously larger than that of the cylindrical specimen, which is 1.10, indicating that the cubic specimen is deeply affected by the size effect. In terms of freeze-thaw cycles, the compressive strength of general concrete decreased by about 10 to 30%, while that of carbon-cured concrete decreased by about 0 to 20%, indicating that carbon-cured concrete has better freeze-thaw resistance. Finally, in the RCPT test, the coulomb values of carbon-cured concrete and general concrete are quite close, which means that they have the same resistance to chloride ions. | en_US |