矿物掺合料对半柔性路面用水泥基灌浆材料的性能影响

Effect of mineral admixtures on properties of cement-based grouting materials for semi-flexible pavement

矿物掺合料是半柔性路面用水泥基灌浆材料组分中的一种重要组成部分,为了探究其对半柔性路面用水泥基灌浆材料性能影响规律,采用单掺矿粉、硅灰和微珠三种矿物掺合料,测试了其水泥基灌浆材料流出时间与抗压强度,并借助XRD和SEM分析了矿物掺合料对灌浆材料水化产物组成与形貌的影响。结果表明:分别添加矿粉和硅灰时,二者均有助于改善水泥基灌浆材料力学性能,当硅灰掺量为2.4%时,其2 h、28 d抗压强度分别增加了1.6、9.8 MPa;微珠对改善水泥基灌浆材料流动性能效果明显,当微珠掺量为20%时,其5、20 min流出时间分别降低了10、15 s。3种矿物掺合料对水泥基灌浆材料早期水化产物的物相组成影响较小,单掺微珠和硅灰使硬化浆体更加密实,且微珠对水化产物钙矾石的形貌影响显著。综合分析3种矿物掺合料对水泥基灌浆材料的强度和流动性试验结果,得到矿粉、硅灰和微珠在灌浆材料组成中的最佳掺量分别为5%、1.6%、10%。

Mineral admixture is an important component of cement-based grouting materials for semi-flexible pavement,in order to investigate the influence of mineral admixtures on the fluidity and mechanical properties of cement-based grouting materials for semi-flexible pavement.The fluidity and compressive strength of cement-based grouting materials were tested by using three mineral admixtures,ground granulated blast furnace slag powder,silica fume and fly ash cenosphere,respectively.The effects of mineral admixtures on the phase composition and morphology of hydration products of grouting materials were analyzed by means of XRD and SEM.The results show that both ground granulated blast furnace slag powder and silica fume are helpful to improve the mechanical properties of cement-based grouting materials.When the silica fume content is 2.4%,the compressive strength at 2 h and28 d increases by 1.6 MPa and 9.8 MPa respectively.The effect of fly ash cenosphere on improving the fluidity of cement-based grouting materials is obvious.When the content of fly ash cenosphere is 20%,the fluidity in 5 min and 20 min is reduced by 10 s and15 s respectively.The three mineral admixtures have little effect on the phase composition of early hydration products of cement-based grouting materials.The hardened pastes are more dense by adding fly ash cenosphere and silica fume respectively,and the fly ash cenosphere have a significant effect on the morphology of ettringite.Based on the comprehensive analysis of the experimental results of the strength and fluidity of the three mineral admixtures on the cement-based grouting materials,it is obtained that the optimum contents of ground granulated blast furnace slag powder,silica fume and fly ash cenosphere in the composition of grouting materials are 5%,1.6%and 10%respectively.