半柔性路面用水泥基灌浆材料的矿物掺合料协同优化研究

矿物掺合料是半柔性路面用水泥基灌浆材料的重要组成部分,各矿物掺合料协同优化对灌浆材料流动性能和力学性能的提升发挥重要作用。本文选用矿粉、微珠和硅灰三种矿物掺合料,通过正交试验研究了三种矿物掺合料协同优化对路面用灌浆材料流动性能和力学性能的影响规律,并借助XRD、SEM等表征方法分析了灌浆材料硬化浆体的水化产物组成与形貌。结果表明,三种矿物掺合料协同优化对灌浆材料流动性能和力学性能的影响顺序为微珠、硅灰和矿粉,其中微珠对灌浆材料流动性能改善效果最为显著,硅灰和矿粉对灌浆材料力学性能提升效果明显。以灌浆材料的流动性能和早期强度为评价指标,微珠、硅灰和矿粉协同优化灌浆材料的最佳掺量分别为15%、1.5%和5%(均为质量分数)。此外,三种矿物掺合料协同掺加对灌浆材料早期水化产物组成与形貌影响较小,表明矿物掺合料协同主要是通过物理填充作用提高了硬化浆体材料的密实度,从而改善灌浆材料早期力学性能。

Cooperative Optimization of Mineral Admixtures of Cement-Based Grouting Materials for Semi-Flexible Pavement

Mineral admixtures are important part of cement-based grouting materials for semi-flexible pavement. The coordination of mineral admixtures plays an important role in improving the fluidity and mechanical properties of grouting materials. In this paper, blast furnace slag powder, cenosphere and silica fume were selected. The effects of the three mineral admixtures on the fluidity and mechanical properties of grouting materials for pavement were investigated by the orthogonal experimental design method, and the hydration product composition and morphology of hardened paste of grouting materials were analyzed by means of XRD and SEM. The results show that the order of influencing factors of the cooperative optimization of three mineral admixtures on the fluidity and mechanical properties of grouting materials is cenosphere, silica fume and blast furnace slag powder.Among them, cenosphere has the most significant effect on improving the fluidity of grouting materials, and silica fume and blast furnace slag powder have the obvious effect on promoting the mechanical properties of grouting materials. According to the evaluating indicator of the fluidity and early strength of grouting materials, the optimum content of cenosphere, silica fume, and blast furnace slag powder is 15.0%, 1.5% and 5.0% (both are mass fraction) respectively. In addition, the synergistic addition of three mineral admixtures has little effect on the composition and morphology of early hydration products of grouting materials. It shows that the improvement of early mechanical properties of grouting materials by three mineral admixtures is mainly caused by the improvement of hardened slurry materials compactness through physical filling.