海水浸泡养护对磷酸钾镁水泥浆体微观结构和性能的影响

发布时间：2018-03-02 07:33

  本文关键词： 磷酸钾镁水泥(MKPC) 海水养护 抗压强度 干燥收缩率 微观结构　出处：《建筑材料学报》2017年05期 　论文类型：期刊论文

【摘要】：为研究海水浸泡养护对磷酸钾镁水泥(MKPC)浆体微观结构和性能的影响,测试了不同养护条件下MKPC浆体试件的抗压强度和干燥收缩率,分析了其物相组成和微观结构.结果表明:在海水浸泡环境下,如果MKPC浆体试件已凝结且具有一定的初始结构强度,其主要水化产物MgKPO_4·6H_2O(MKP)在呈弱碱性的海水环境下溶解度低、水解现象减轻;海水的渗入使MKPC浆体试件的水化反应得以持续进行,水化反应生成较多的MKP,在弱碱性海水环境下,MKP更易结晶,生成的MKP晶体结晶程度高、缺陷少,后续生成的MKP晶体不断填充MKPC硬化体的孔隙,使硬化体结构趋于致密;自然养护3d后浸入海水养护的MKPC试件有较高的抗压强度和较低的干燥收缩率,其28,60d抗压强度较全程自然养护的MKPC试件分别提高13%和5%,而其60d干燥收缩率仅为全程自然养护MKPC试件的12%,为28d后浸入海水养护MKPC试件的23%.
[Abstract]:For the study of seawater immersion and maintenance of potassium magnesium phosphate cement (MKPC) effect of paste microstructure and properties, compressive strength and dry shrinkage rate of MKPC slurry under different curing conditions were tested, analyzed the phase composition and microstructure. The results showed that: in the seawater environment, if MKPC paste the specimen has been condensed with initial structural strength, the main hydration products of MgKPO_4 6H_2O (MKP) in weakly alkaline water under low solubility, hydrolytic reduce the infiltration of water; MKPC slurry hydration reaction test piece can be sustained in water, reaction more MKP. In the alkalescent water environment, MKP crystallization, the crystallization of MKP generated high degree, less defect, MKP crystals generated continuously filled MKPC subsequent hardening of pores, the structure of hardened body tends to be dense; the sea water immersion after natural curing 3D curing MKPC specimen The compressive strength and dry shrinkage rate of 28,60d were higher than that of MKPC test piece. The compressive strength of the 60d increased by 13% and 5% compared with that of the whole natural curing test, while the 60d dry shrinkage rate was only 12% of that of the whole natural curing MKPC.

【作者单位】： 盐城工学院土木工程学院;江苏省生态建材与环保装备协同创新中心;
【基金】：国家自然科学基金资助项目(51578475) 住房和城乡建设部科研开发项目(2014-K4-031,2014-K4-024;住建厅科技项目2014ZD97/101)
【分类号】：P75;TV431
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本文编号：1555607