We demonstrated the sensitivity of optically active single-walled carbon nanotubes (SWCNTs) with a diameter below 1 nm that were homogeneously dispersed in cement composites under a mechanical load. Deoxyribonucleic acid (DNA) was selected as the dispersing agent to achieve a homogeneous dispersion of SWCNTs in an aqueous solution, and the dispersion state of the SWCNTs were characterized using various optical tools. It was found that the addition of a large amount of DNA prohibited the structural evolution of calcium hydroxide and calcium silicate hydrate. Based on the in-situ Raman and X-ray diffraction studies, it was evident that hydrophilic functional groups within the DNA strongly retarded the hydration reaction. The optimum amount of DNA with respect to the cement was found to be 0.05 wt%. The strong Raman signals coming from the SWCNTs entrapped in the cement composites enabled us to understand their dispersion state within the cement as well as their interfacial interaction. The G and G’ bands of the SWCNTs sensitively varied under mechanical compression. Our results indicate that an extremely small amount of SWCNTs can be used as an optical strain sensor if they are homogeneously dispersed within cement composites.

본 연구는 폭발과 같은 극한 하중이 가해지는 콘크리트의 역학적 거동에 대해 다루고 있다. 극한 하중을 받는 콘크리트는 정적 하중을 받을 때보다 증가하며, 동적 강도와 정적강도의 비를 동적증가계수(Dynamic Increase Factor)로 나타낸다. 동적 증가계수는 지금까지 하나의 변수를 가지고 다루어져 왔기 때문에 콘크리트의 설계 및 분석에 어려움이 존재하기 때문에 동적 증가계수에 영향을 주는 여러 변수를 찾아 베이지안을 통해 분석하여 폭발사고가 일어날 가능성이 있는 전기, 전자 및 화학 플랜트 혹은 반도체 공정 등에 사용한다면 피해가 줄어들 것이다.