硫酸钠掺量对中性钠盐粉煤灰水泥水化程度和抗压强度的影响机理  

Influence Mechanism of Sodium Sulfate Content on Hydration Degree and Compressive Strength of NSFC

作　　者：高巧玲 GAO Qiaoling(Department of Architectural Engineering,Fujian Chuanzheng Communications College,Fuzhou,Fujian 350007,China;College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350116,China)

机构地区：[1]福建船政交通职业学院建筑工程系 [2]福州大学土木工程学院

出　　处：《湖南城市学院学报（自然科学版）》2019年第4期15-21,共7页Journal of Hunan City University:Natural Science

基　　金：福建省中青年教师教育科研基金项目(JAT160708)

摘　　要：通过测试不同硫酸钠掺量(0,2%,4%和6%)在不同龄期(3,7,28和56d)下中性钠盐粉煤灰水泥(NSFC)的抗压强度,研究标准养护下硫酸钠掺量对NSFC抗压强度的影响﹒通过XRD、SEM、孔结构和NMR等试验分析NSFC水化产物的种类和形貌、孔结构分布、净浆孔溶液pH值以及NSFC中普通硅酸盐水泥和粉煤灰的反应程度,揭示硫酸钠掺量对其水化程度和抗压强度的影响机理﹒研究表明,当硫酸钠掺量小于4%时,NSFC的碱性随硫酸钠掺量的增大而增强,粉煤灰在强碱环境中水化反应加速,C-S-H、钙矾石等生成量增加,有害孔和多害孔减少,微观结构变得密实,胶空比增大,抗压强度增大;当硫酸钠掺量增加到6%时,过量的钙矾石胀裂孔隙,有害孔和多害孔反而增加,胶空比减小,抗压强度减小.By testing the compressive strength of neutral sodium salt fly-ash cement (NSFC) with different sodium sulfate contents (0,2%,4%,and 6%) at different curing ages (3,7,28 and 56 d),the influence of sodium sulfate content on the compressive strength of NSFC under standard curing is investigated.According to the test results of XRD,SEM,pore structure and NMR,the species and morphology of hydration products,the pore structure,the pH values of pore solution and the hydration degree of Portland cement and fly ash in NSFC are analyzed,and the influence mechanism of sodium sulfate content on the hydration degree and compressive strength of NSFC is investigated.The results show that when the increase of sodium sulfate content is less than 4%,the alkaline of NSFC strengthens with the increase of sodium sulfate content,the hydration of fly ash accelerates,the amount of C-S-H and ettringite etc.increases, the harmful pore and much harmful pore reduce,the microstructure of NSFC becomes denser,the gel/space ratio increases,and therefore the compressive strength of NSFC increases.When the sodium sulfate content increases to 6%,the excess of ettringite will burst the pore,the harmful pore and much harmful pore increase, the gel/space ratio decreases and the compressive strength of NSFC decreases.

关 键 词：硫酸钠掺量 中性钠盐粉煤灰水泥 抗压强度 水化程度 核磁共振 

分 类 号：TU52[建筑科学—建筑技术科学]