浅析泡沫水泥稳泡及水化机理

FOAM STABILIZING AND HYDRATION MECHANISM OF CELLULAR CEMENT

讨论了泡沫水泥中泡沫剂、稳泡剂、促凝剂的种类、掺量及其比例关系对泡沫水泥稳泡、水化等性能的影响，用ｘ射线衍射、热失重曲线和扫描电镜方法分析了水化过程、水化产物结构、水化机理和稳泡机理．研究表明：泡沫水泥稳泡性能受浆体中金属离子价位、种类的影响，水化过程分初期、早期和后期，早期产物为ＡＦｔ相，ｌｄ以后可见ＡＦｍ和铝胶．．由于我国目前生产的高铝水泥中Ｃ１２Ａ７的含量很少，满足不了泡沫水泥的性能要求，而用国产以Ｃ４Ａ３Ｓ为主要矿物组成的硫铝酸盐早强水泥研制出的泡沫水泥性能较为理想．泡沫水泥充填空洞时，是使用水泥充填专用泵，几乎不需要成型时间。泡沫水泥浆体中泡沫稳定时间，经测定在１２ｍｉｎ左右，超过稳定时间，浆体就会出现破泡、塌落．通过对稳泡和水化机理的研究，选择了与水泥相适应的泡沫剂、稳泡剂、促凝剂等［１］，反复调整它们之间的比例关系，控制泡沫水泥的凝结时间在１０ｍｉｎ之内，即在泡沫尚未破裂之前，水泥浆体就已经凝结硬化，并产生强度，支承结构．泡沫水泥是采用大水灰比，最高可达１．６：１．配方中的泡沫剂为缓凝型，寻找出理想的促凝剂，使浆体的凝结时间缩短到１０ｍｉｎ，且不影响泡沫剂的稳定性能是问题的关键之一，对于泡沫水?

The effects of type,amount and ratio of foam agent,foam stabilizing agent and accelerator on foam stabilization and hydration of cellular concrete are discussed.X-ray diffraction,heat weight loss curve,and scanning electron microscope methods are used to study the hydration process,the structure of hydration products,mechanism of foam stabilization and hydration.The result is that the foam stabilization performance is affected by valence and type of metal ion in the mortar, and the hydration process includes initial, middle and later stages.The product of initial hydration period is AFt phase.AFm and aluminum gel are found after one day.