Physical and Chemical Properties of Cement Mortar with Gamma-C2S

• Lee, Sung-Hyun ;
• Kim, Kyungnam ;
• Mabudo, Mabudo ;
• Song, Myong-Shin
• Accepted : 2016.02.26
• Published : 2016.03.31
• 10 0

Abstract

Presently, for the cement industry, studies that seek to reduce $CO_2$, because of the development of the plastic industry and demand for reduction of energy use, have been actively conducted among them, studies attempting to use Gamma-$C_2S({\gamma}-C_2S)$ to fix $CO_2$ have been actively conducted. The ${\gamma}-C_2S$ compound has an important function in reacting to $CO_2$ and stiffening through carbonatization in the air. The ${\gamma}-C_2S$ compound, reacting to $CO_2$ in the air, generates $CaCO_2$ within the pore structure of cement materials and densifies the pore structure this leads to an improvement of the durability and to the characteristic of resistance against neutralization. Therefore, in this experiment, in order to synthesize ${\gamma}-C_2S$, limestone sludge and waste foundry sands are used these materials are plasticized for 30 or 60 minutes at $1450^{\circ}C$, and are prevented from being cooled in the temperature range of $30{\sim}1000^{\circ}C$ when they are about to be cooled. XRD analysis and XRF analysis are used to determine the effects of this process on ${\gamma}-C_2S$ synthesization, the temperature at which a thing is plasticized, and the conditions for cooling that obtain in the plasticized clinker also, in order to confirm the $CO_2$ capture function, analysis of the major hydration products is conducted through an analysis of carbonatization depth and compressive strength, and through MIP analysis and XRD Rietveld analysis. As a result of these analyses, it is found that when ${\gamma}-C_2S$ was synthesized, the clinker that was plasticized at $1450^{\circ}C$ for one hour demonstrated the highest yield rate the sample with which the ${\gamma}-C_2S$ was mixed generated $CaCO_3$ when it reacted with $CO_2$ therefore, carbonatization depth and porosity were reduced, and the compressive strength was increased.

Keywords

$CO_2$ capture;Pore;Vaterite;Gamma-$C_2S$

References

1. C.-W. Park, "Eco-Friendly of Concrete," Mag. Korea Concr. Inst., 20 [6] 24-6 (2008).
2. S.-H. Lee, "Hydration Mechanism of Ground Granulated Blast Furnace Slag," Mag. Korea Concr. Inst., 24 [6] 31-4 (2012).
3. J. I. Escalante-Garcia, "Portland Cement-Blast Furnace Slag Mortars Activated Using Waterglass: Effect of Temperature and Alkali Concentration," Construct. Build. Mater., 66 323-28 (2014). https://doi.org/10.1016/j.conbuildmat.2014.04.120
4. K. J. Mun, "The Effect of Slaked Lime, Anhydrous Gypsum and Limestone Powder on Properties of Blast Furnace Slag Cement Mortar and Concrete," Construct. Build. Mater., 21 1576-82 (2007). https://doi.org/10.1016/j.conbuildmat.2005.09.010
5. H. Sakamoto, "pH Behavior of Hydrated Low-Alkalinity Cement," J. Nucl. Fuel Cycle Environ., 5 [2] 37-42 (1999). https://doi.org/10.3327/jnuce.5.37
6. F. Winnefeld, "Hydration of Calcium Sulfo-Aluminate Cements - Experimental Findings and Thermodynamic Modelling," Cem. Concr. Res., 40 1239-47 (2010). https://doi.org/10.1016/j.cemconres.2009.08.014