超细硅灰石粉对水泥基材料性能的影响

Effect of Wollastonite Ultrafine Powder on the Properties of Cement-Based Materials

在测定超细硅灰石粉特性及其胶砂强度指数的基础上,研究了超细硅灰石粉对水泥砂浆流动性、试件强度及抗化学侵蚀性能的影响。结果表明:超细硅灰石粉是长径比在(18~25)∶1的纤维状粒子,其胶砂强度指数为72.9%,将超细硅灰石粉掺入水泥基材料中能够提高水泥试件的抗折强度与折压比,但由于硅灰石粉具有较大的细度与长径比,硅灰石粉掺量超过15%时砂浆扩展度会明显降低。当硅灰石粉掺量为15%~20%范围时,在水泥试件抗压强度没有明显降低的情况下,能够提高水泥试件的抗折强度10%以上,同时折压比接近0.20,有利于改善水泥基材料的脆性。同时,硅灰石粉掺量不超过30%的水泥试件具有良好的抗化学侵蚀性能,且抗蚀系数大于0.80。

Based on characteristics of wollastonite ultrafine powder and cement mortar strength index, effect of the wollastonite on the fluidity of cement mortar, strength and resistance to chemical erosion of cement mortar were carried out. The results show that the wollastonite ultrafine powder is fibriform with average aspect ratio of about(18-25)∶1, and the cement mortar strength index was 72.9%. Adding the wollastonite ultrafine powder in cement-based materials would improve their flexural strength and the ratio of flexural to compressive strength, but more than 15% wollastonite to replace cement content would lead to a significant drop of cement mortar fluidity, as the wollastonite is a powder with large fineness and aspect ratio. The results also show that the flexural strength was increased by more than 10% and the ratio of flexural to compressive strength was close to 0.20 when the amount of wollastonite was 15% to 20% of cement content, while the compressive strength had no significant loss, this is advantageous to improve the brittleness of cement-based materials. The sample added by less than 30% wollastonite had good corrosion resistance to chemicals, and the corrosion resistance coefficient was more than 0.80.