腐殖酸和富里酸对碱式硫酸镁水泥性能的影响

Effect of Humic Acid and Fulvic Acid on Properties of Basic Magnesium Sulfate Cement

讨论了腐殖酸和富里酸在不同掺量下对碱式硫酸镁水泥的影响。研究结果表明,随着腐殖酸和富里酸掺量的增加,水泥基体的流动性逐渐增强,初凝和终凝时间相对延长。此外,腐殖酸和富里酸在较低掺量下对水泥的强度影响较小。具体而言,当腐殖酸掺量在0.3%和0.5%之间时,抗压抗折强度逐渐增加;然而,当掺量达到0.7%、0.9%和1.1%时,强度则呈逐渐降低的趋势。相比之下,富里酸在0.3%掺量以下时,抗压抗折强度呈上升趋势,但掺量在0.5%及以上时,强度逐渐减小。通过对微观结构的观察,发现在0.5%的腐殖酸和富里酸掺量下,水泥基体密实,孔隙较小,颗粒间排列相对有序;而在1.1%的腐殖酸掺量下,氧化镁颗粒减少,裂缝增多,颗粒之间相对较松散。总体而言,两种酸对碱式硫酸镁水泥的影响主要体现在对5·1·7相的抑制,导致碳酸镁含量上升,从而引起水泥基体的劣化。

This study explores the influence of different concentrations of humic acid and fulvic acid on basic magnesium sulfate cement.The results indicate that an increase in the concentration of humic acid and fulvic acid enhances the fluidity of the cement matrix.Setting times,both initial and final,show improvement.Humic and fulvic acids have a low effect on the strength of cement at lower dosages small.Compressive and flexural strength exhibit a rising trend at humic acid concentrations of 0.3%and up to 0.5%.However,at concentrations of 0.7%,0.9%,and 1.1%,the strength decreases.Concerning fulvic acid,the compressive and flexural strength increase at concentrations of 0.3%and up to 0.5%,but beyond the 0.5%threshold,there is a continuous decrease in strength.Microstructural analysis shows that at a concentration of 0.5%,the matrix is dense,with small pore sizes and relatively orderly particle arrangements.Conversely,at a concentration of 1.1%humic acid,there are fewer magnesium oxide particles,an increased number of cracks,and a relatively loose particle arrangement.The influence of the two acids on basic magnesium sulfate cement is mainly reflected in the inhibition of the 5·1·7phase,leading to an increase in magnesium carbonate content and the degradation of the cement matrix.