School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang, 621010, PR China; State Key Laboratory for Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang, 621010, PR China; State Key Laboratory of Green Building Materials, China Building Materials Academy, Beijing, 100024, PR China.
School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, PR China.
J Environ Manage. 2020 Feb 15;256:109878. doi: 10.1016/j.jenvman.2019.109878. Epub 2019 Dec 5.
Basic magnesium sulfate cement has the advantages of fast setting, high strength, high toughness, water resistance, corrosion resistance, etc. But the cost has become a reason for limiting its widespread application. With the widespread application of circulating fluidized bed combustion (CFBC) technology in China, the accumulation of CFBC ash is increasing. Reasonable use of CFBC ash can not only reduce cost of basic magnesium sulfate cement but also protect environment. In this paper, the effect of a high volume of CFBC ash on fluidity, flexural strength and compressive strength of basic magnesium sulfate cement is studied. Hydration products and micromorphology analyses are measured by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results reveal that the strength of basic magnesium sulfate cement with 20% CFBC ash is the highest, and its microstructure is the model that CFBC ash and MgO fill a three-dimensional network structure established by needle-shaped 5·1·7 phase. When the amount of CFBC ash is more than 40%, the formation of 5·1·7 phase is affected severely, which greatly reduces the strength.
基本硫酸镁水泥具有凝结速度快、强度高、韧性高、耐水、耐腐蚀等优点。但成本已成为限制其广泛应用的一个原因。随着循环流化床燃烧（CFBC）技术在中国的广泛应用，CFBC 灰的积累量不断增加。合理利用 CFBC 灰不仅可以降低基本硫酸镁水泥的成本，还可以保护环境。本文研究了高体积 CFBC 灰对基本硫酸镁水泥流动性、弯曲强度和抗压强度的影响。通过 X 射线衍射（XRD）和扫描电子显微镜（SEM）测量水化产物和微观形貌。结果表明，掺 20%CFBC 灰的基本硫酸镁水泥强度最高，其微观结构为 CFBC 灰和 MgO 填充由 5·1·7 相针状组成的三维网络结构的模型。当 CFBC 灰的量超过 40%时，5·1·7 相的形成受到严重影响，从而大大降低了强度。
