【摘要】 主要研究了稻草纤维碱处理液对碱式硫酸镁水泥凝结时间、流动度和强度的影响,同时利用XRD对水泥水化产物的物相组成进行了分析。研究结果显示,稻草纤维中的萃取物对水泥浆体有缓凝作用,并使得水泥浆体的流动度降低,早期强度也较低。由于纤维萃取物阻止了水泥浆体中MgO水解生成[Mg（OH）（H₂O）_x]⁺,抑制了早期水化产物中5Mg（OH）₂·MgSO₄·7H₂O（5·1·7）相的形成,因而早期强度发展缓慢。与溶剂为水的碱式硫酸镁水泥相比,碱处理过程中NaOH溶液加速了水泥的正常凝结,降低了水泥浆体的流动性,并对强度的发展有抑制作用。NaOH与MgSO₄反应生成Mg（OH）₂,使得水泥浆体中Mg²⁺减少,Mg（OH）₂含量增加,导致水泥强度有所降低。更多还原

【Abstract】 The influence of straw fiber alkaline extractives on setting time,fluidity and strength of basic magnesium sulfate cement were studied. The phase composition of hydration products in harden cement were tested by XRD. The results show that water-solubles present in straw fiber decrease the fluidity and retard the setting time of cement,and the strength of cement in early period is reduced. The extracts present in straw fiber have an adverse effect on MgO hydration and the formation of [Mg（OH）（H₂O）_x]⁺ formed. Therefore,the growth of 5 Mg（OH）₂·MgSO₄·7 H₂O（ 5·1·7） phase is inhibited and the development of the cement strength in early stage is slow. Comparing with the basic magnesium sulfate cement mixed with H₂O,the NaOH solution accelerate the setting time,interfere the normal fluidity and strength development process of the cement. The content of Mg²⁺ is reduced due to the forming of Mg（OH）₂ after the reaction between NaOH and MgSO₄,leading to the reduction of cement strength.更多还原