Shiferaw Natnael, Habte Lulit, Thenepalli Thriveni, Ahn Ji Whan
Korea Research Institute on Climate Change, 11, Subyeongongwon-gil, Chuncheon-si 24239, Korea.
Department of Resources Recycling, University of Science & Technology, 217 Gajeong-ro, Gajeong-dong, Yuseong-gu, Daejeon 34113, Korea.
Materials (Basel). 2019 Aug 5;12(15):2483. doi: 10.3390/ma12152483.
Eggshells are one of the solid wastes in the world and are considered hazardous according to European Commission regulations. The utilization of solid wastes, like eggshells, will help create a sustainable environment by minimizing the solid wastes that are disposed into the environment. The utilization of eggshell powder in cement also helps to reduce the carbon dioxide emissions from cement factories by reducing clinker production. In this study, the effect of eggshell powder on the hydration of cement products was investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Pastes were made with 10% and 20% eggshell powder and examined for 1, 14, and 28 days of hydration. The addition of eggshell powder transformed ettringite to monosulfoaluminate and to monocarboaluminate. In 20% eggshell powder, the formation of monocarboaluminate was detected in the early stages and accelerated the hydration reaction. The CaCO from the eggshells reacted with the CA and changed the hydration products of the pastes. The addition of eggshell powder provided nucleation sites in the hydration products and accelerated cement hydration.
蛋壳是世界上的固体废物之一，根据欧盟委员会的规定被视为危险废物。像蛋壳这样的固体废物的利用，将通过尽量减少排放到环境中的固体废物来帮助创造一个可持续的环境。蛋壳粉在水泥中的利用也有助于通过减少熟料生产来降低水泥厂的二氧化碳排放量。在本研究中，使用X射线衍射（XRD）、热重分析（TGA）、傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）研究了蛋壳粉对水泥产品水化的影响。制备了含有10%和20%蛋壳粉的浆体，并对其水化1天、14天和28天的情况进行了研究。蛋壳粉的添加将钙矾石转化为单硫铝酸钙和单碳铝酸钙。在含有20%蛋壳粉的情况下，在早期阶段检测到了单碳铝酸钙的形成，并加速了水化反应。蛋壳中的碳酸钙与CA反应，改变了浆体的水化产物。蛋壳粉的添加在水化产物中提供了成核位点，并加速了水泥的水化。
