In the present work, the synergetic effect of fly ash (FA) and ground granulated blast furnace slag (GGBS) on the compressive strength and microstructure development of mortars subjected to CO curing coupled with further water curing was investigated. The calcite content in pure cement was first increased and then decreased, while it decreased gradually in cement incorporating FA and GGBS during further water curing. Ettringite was interlocked with calcium carbonate and MC and was only observed in pure cement paste. Two distinct forms of C–S–H were observed in pure cement with one being interlocked with calcite, while the other one was pure amorphous phase. The incorporation of FA and GGBS showed a negative effect on the polymerization decrease of silica-rich phase. FA showed a negligible effect on the decrease of porosity, while GGBS had a positive effect on it. A positive correlation was found between the increase of compressive strength subsequent to water curing and three parameters, i.e., crystal size of calcite, carbonation degree and capillary pore percentage after CO curing, where the carbonation degree had a negative effect, while the other two parameters had a positive effect. The incorporation of GGBS and FA had a positive effect on the strength increase rate during further water curing. Notably, GGBS showed a more obvious effect on the strength development during further water curing and normal curing at later age. When GGBS content was lower than 10 % or cement content was lower than 10 %, the increase of FA content had a positive effect on the strength increase.

中文翻译：

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进一步水固化掺入粉煤灰和矿渣的 CO2 固化水泥的性能


在目前的工作中，研究了粉煤灰（FA）和磨碎的粒化高炉矿渣（GGBS）对经过CO固化和进一步水固化的砂浆的抗压强度和微观结构发展的协同作用。纯水泥中方解石含量先增加后减少，而掺入FA和GGBS的水泥中方解石含量在进一步水养护过程中逐渐减少。钙矾石与碳酸钙和MC互锁，仅在纯水泥浆中观察到。在纯水泥中观察到两种不同形式的 C-S-H，其中一种与方解石互锁，而另一种是纯非晶相。 FA 和 GGBS 的加入对富二氧化硅相的聚合减少产生了负面影响。 FA 对孔隙率降低的影响可以忽略不计，而 GGBS 对孔隙率的降低有积极的影响。结果发现，水养护后抗压强度的增加与CO养护后方解石晶体尺寸、碳化度和毛细孔百分比三个参数呈正相关，其中碳化度起负作用，而其他两个参数则呈正相关。起到了积极的作用。 GGBS 和 FA 的加入对进一步水固化过程中的强度增加率有积极的影响。值得注意的是，GGBS 在进一步水养护和后期正常养护过程中对强度发展表现出更明显的影响。当GGBS含量低于10%或水泥含量低于10%时，FA含量的增加对强度增加有正向作用。