矿物掺合料对海水中氯离子的结合能力

Bonding Performance of Mineral Admixture to Chloride in Sea Water

研究了0～50％粉煤灰净浆、0～65％矿渣净浆以及0～8％硅灰净浆在海水和NaCl两种溶液中的氯离子结合规律。结果表明：净浆在NaCl溶液中，其结合氯离子量为4．8～4．9mg Cl^-/g净浆；海水中存在的SO4^2-降低了Friedel盐的生成量，使净浆的结合氯离子量降低33%～46％。矿渣及0～35％的粉煤灰能提高净浆的氯离子结合能力，而硅灰的掺入降低了净浆的结合氯离子量。当矿渣和粉煤灰掺量为35％和15％时，净浆的结合氯离子量最大。随浸泡龄期延长，大掺量矿粉净浆的结合氯离子量会相应增加。最后，使用DTG和XRD技术研究了上述规律产生的微观机理。

The bonding performance to chloride of plain paste, pastes with 0-50% fly ash, paste with 0-65% GGBS （ground granulate blast furnace slag） and paste with 0-8% silica fume was investigated in NaCl solution and sea water. The results show that the bound amount of chloride was about 4.8-4.9 mg Cl^-/g paste in NaCl solution, and it was reduced by about 33%-46% in sea water because the formation of ettringite resulted in the decrease of Friedel＇s salt content. GGBS or 0-35% fly ash could improve the bonding capacity of the pastes to chloride, while silica fume decreased it. The bound chloride content was maximal for pastes with 35% GGBS or 15% fly ash. Additionally, the bound chloride content of the paste with a great deal of GGBS increased with the increase of immersion time. The mechanism was also investigated by DTG （differential thermomeehanic analysis） and XRD（X- ray diffraction） techniques.