摘要
通过化学合成钙矾石和水化硅酸钙,利用XRD、27 Al核磁共振测试手段,研究了氯离子环境下钙矾石(AFt)和水化硅酸钙(C-S-H)凝胶体系中铝配位分布规律。结果表明,在C-S-H凝胶和氯离子共存环境中,第三类水化铝酸盐(TAH)凝胶中六配位铝(Al[6])首先转化为四配位铝(Al[4])进入C-S-H结构,且Al[4]总量不受C-S-H钙硅比限制;同时氯离子不影响Al[6]-TAH向Al[4]转化,当达到C-S-H凝胶容纳Al[4]的极限时,剩余的Al[6]-TAH才与氯离子反应形成Friedel盐(F盐)。TAH比AFt更容易与氯离子反应形成F盐;低钙硅比C-S-H环境不利于TAH与氯离子结合,但利于钙矾石分解并与氯离子反应生成F盐。
The distribution of aluminum coordination in the ettringite and C-S-H gels system under chloride ions environment was investigated through chemical synthesis of ettringite and C-S-H gels and by XRD,27 Al Nuclear Magnetic Resonance(NMR).The results indicate that in the coexistence environment of C-S-H gels and chloride ions,the 6-coordination aluminum(Al[6])in the TAH(third aluminum hydrate)gels firstly transforms into the 4-coordination aluminum(Al[4])entering into C-S-H structure,and the total amount of Al[4]in that C-S-H is not restricted by the Ca/Si ratio of them;meanwhile,the transformation from Al[6]-TAH to Al[4]is not influenced by chloride ions,and the remainder Al[6]-TAH reacts with chloride ions to form the Friedel's salts(F's),when the amount of Al[4]reaches the capability limit of C-S-H gels.Furthermore,the reaction of TAH with chloride ions is more easier than that of ettringite to form the F's,and the environment of low Ca/Si ratio C-S-H gels does not favor for the reaction of the TAH with chloride ions,on the contrary,it promotes the decomposition of ettringite to form the F's in environment of chloride ions.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2018年第2期2146-2151,共6页
Journal of Functional Materials
基金
河北省自然科学基金资助项目(E2016209283)
高性能土木工程材料国家重点实验室开放基金资助项目(2015CEM005)
河北省科技计划资助项目(16273706D)
