Feng Shihui, Zhu Jing, Wang Ruixuan, Qu Zijian, Song Lizhuo, Wang Hui
College of Civil Engineering and Architecture, Harbin University of Science and Technology, Harbin 150080, China.
School of Civil and Environmental Engineering, Ningbo University, Ningbo 315000, China.
Materials (Basel). 2022 Sep 3;15(17):6128. doi: 10.3390/ma15176128.
CaO and MgO are both reported as effective activators for blast furnace slag. However, the synergistic effect of these two components on the mechanical properties of alkali-activated blast furnace slag remains unclear. In this study, the flexural and compressive strengths of alkali-activated blast furnace slag powder with MgO and CaO range from 0% to 30% by the mass ratio of alkali-activated blast furnace slag powder are investigated. Moreover, the dry shrinkage rate of alkali-activated blast furnace slag powder is measured. One percent refractory fibers by volume of binder materials are added in the alkali-activated blast furnace slag. Some refractory fibers are treated with water flushing, meanwhile, some refractory fibers are directly used without any treatment. Finally, the scanning electron microscope, the thermogravimetric analysis curves and the XRD diffraction spectrums are obtained to reflect the inner mechanism of the alkali-activated blast furnace slag powder's mechanical properties. The water-binder ratios of the alkali-activated blast furnace slag powder are 0.35 and 0.42. The curing ages are 3 d, 7 d and 28 d. The measuring temperature for the specimens ranges from 20 °C to 800 °C. Results show that the flexural and compressive strengths increase with the increased curing age, the decreased water-binder ratio and the addition of refractory fibers. The water-treated refractory fibers can improve the mechanical strengths. The mechanical strengths increase in the form of a quadratic function with the mass ratio of MgO and CaO, when the curing age is 3 d, the increasing effect is the most obvious. A higher water-binder ratio leads to an increasing the drying shrinkage rate. The activated blast furnace slag powder with CaO shows a higher drying shrinkage rate. The mechanical strengths decrease with the increasing testing temperature.
氧化钙（CaO）和氧化镁（MgO）均被报道为高炉矿渣的有效激发剂。然而，这两种成分对碱激发高炉矿渣力学性能的协同作用仍不明确。在本研究中，研究了氧化镁和氧化钙质量比在0%至30%范围内的碱激发高炉矿渣粉的抗折强度和抗压强度，该质量比基于碱激发高炉矿渣粉。此外，还测量了碱激发高炉矿渣粉的干缩率。在碱激发高炉矿渣中加入占粘结材料体积1%的耐火纤维。部分耐火纤维经过水洗处理，同时，部分耐火纤维未经任何处理直接使用。最后，获得扫描电子显微镜图像、热重分析曲线和XRD衍射图谱，以反映碱激发高炉矿渣粉力学性能的内在机理。碱激发高炉矿渣粉的水胶比为0.35和0.42。养护龄期为3天、7天和28天。试件的测量温度范围为20℃至800℃。结果表明，抗折强度和抗压强度随养护龄期的增加、水胶比的降低以及耐火纤维的加入而提高。经过水处理的耐火纤维可提高力学强度。当养护龄期为3天时，力学强度随氧化镁和氧化钙质量比呈二次函数形式增加，增强效果最为明显。较高的水胶比导致干缩率增加。含氧化钙的活性高炉矿渣粉干缩率较高。力学强度随测试温度的升高而降低。
