外加剂和粉煤灰对碱式硫酸镁水泥混凝土性能影响研究

Influence of Admixture and Fly Ash on Performance of Basic Magnesium Sulfate Cement Concrete

利用碱式硫酸镁水泥制备了不同外加剂和粉煤灰掺量的碱式硫酸镁水泥(BMSC)混凝土。研究了外加剂和粉煤灰对BMSC混凝土抗压强度以及抗硫酸盐腐蚀性能的影响,并对BMSC混凝土物相组成和微观形貌进行了分析。结果表明:掺加外加剂后混凝土的强度有大幅度地提高。当外加剂掺量为水泥质量的0.5%时,混凝土的强度达到最大值;继续增加外加剂掺量,对混凝土的强度影响不大。掺加粉煤灰后,混凝土的强度有所下降。且水灰比一定时,粉煤灰掺量越多,对混凝土的强度越不利。掺加外加剂和粉煤灰后,混凝土的抗硫酸盐腐蚀性能得到了明显的改善;且同等条件下,碱式硫酸镁水泥混凝土抗硫酸盐腐蚀性能优于普通硅酸盐水泥混凝土。

Basic magnesium sulfate cement concrete were prepared by using basic Magnesium Sulfate cement with different dosages of admixture and fly ash. The effect of admixture and fly ash on the compressive strength of BMSC concrete and the resistance to sulfate corrosion were studied, and the phase composition and microstructure of BMSC concrete were also analyzed. The results show that after adding admixture the strength of the concrete was greatly enhanced. When the dosage of admixture is 0. 5% of the quality of cement, the strength of the concrete reaches maximum value. Continue to increase the amount of admixture, the strength of concrete has little effect. The strength of concrete is decreased after adding fly ash. And when the water cement ratio is constant, the more fly ash content, the more unfavorable to the strength of concrete. After adding admixture and fly ash, the resistance to sulfate corrosion of concrete has been improved obviously. And under the same condition, the resistance to sulfate corrosion of the basic Magnesium Sulfate cement is better than that of ordinary portland cement concrete.