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Experimental Study on Accelerated Carbonation Characteristics of OPC Paste for CSC-Based Low Carbon Precast Concrete Products

CSC 기반 저탄소 콘크리트 2차제품 제조를 위한 OPC 페이스트의 촉진탄산화 특성에 관한 실험적 연구

  • Received : 2024.02.07
  • Accepted : 2024.05.13
  • Published : 2024.06.20

Abstract

This study investigated the impact of accelerated carbonation on Ordinary Portland Cement(OPC) paste that had undergone steam curing at 500℃·hr. Two carbonation environments were examined: atmospheric carbonation(1atm, 20% CO2) and pressurized carbonation(5atm, 99% CO2). Chemical analysis using X-ray diffraction(XRD) and Fourier-Transform Infrared spectroscopy(FT-IR) were conducted, along with physical characterization via scanning electron microscopy(SEM) and compressive strength testing. Results indicated that atmospheric carbonation with 20% CO2 concentration significantly densified the internal microstructure of the OPC paste, leading to enhanced compressive strength. Conversely, pressurized carbonation at 5atm with 99% CO2 concentration resulted in rapid densification of the surface structure, which hindered CO2 diffusion into the sample. This limited the extent of carbonation and prevented the improvement of physical properties.

본 연구에서는 500℃·hr의 증기양생을 실시한 OPC 페이스트에 대하여 1atm 20% 농도의 CO2와 5atm 99% 농도의 고농도 CO2 조건 하의 촉진 탄산화의 영향평가를 수행하였다. 이를 위하여 XRD, FT-IR을 통한 화학적 분석과 SEM, 압축강도 측정을 통한 물리적 특성 분석을 실시하였다. 그 결과 CO2 20% 농도의 상압 탄산화를 수행하는 경우 뚜렷한 내부 조직구조 치밀화 및 압축강도 증진 효과를 관찰할 수 있었고, CO2 99% 농도의 5atm 가압 탄산화를 실시할 경우 표면조직구조가 빠르게 치밀해지며 CO2 확산침투율이 크게 떨어지게 되어 압축강도 등 유의미한 수준의 물리적 특성 개선이 일어날 정도의 탄산화를 진행할 수 없었다.

Keywords

Acknowledgement

This experiment research had been conducted under the financial support provided by the R&D program(Development of calcium silicate cement and cement products, RS-2023-00155521) of KEIT.

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