偏高岭土对水泥净浆火山灰效应强度贡献率的影响

Influence of Metakaolin on Strength Contribution Rate of Pozzolanic Effect in Cement Paste

根据蒲心诚教授提出的偏高岭土火山灰效应定量分析方法,进行了偏高岭土对水泥净浆(以下简称净浆)火山灰效应强度贡献率(以下简称强度贡献率)的影响研究.结果表明:随着偏高岭土掺量的增加,其净浆强度贡献率增加;随着养护龄期的增加,其净浆强度贡献率呈现先减少后增加的趋势,且7,d时出现最低值;3、28,d时小粒径偏高岭土(2.5和3.75,μm)的净浆强度贡献率明显高于7,d时的值,这说明偏高岭土火山灰效应主要是发生在早期(3,d)和后期(28,d);而大粒径偏高岭土和补充激发剂则有利于提高其中期(7,d)净浆强度.

By using the quantitative analysis method of metakaolin pozzolanic effect proposed by Professor Pu Xincheng, the authors of this paper conducted a research on the influence of metakaolin on the strength contribution rate of pozzolanic effect in cement paste. The results show that, the strength contribution rate of pozzolanic effect on cement paste increases as the amount of metakaolin increases; the strength contribution rate of pozzolanic effect on cement paste decreases and then increases with the increase of the curing age, and its lowest value occurs during 7days; with smaller particle metakaolin （2.5 and 3.75 μm）, the strength contribution rate of pozzolanic effect on cement paste during 3 days is obviously higher than during 7 days. This shows that in paste there is the higher physical filling and pozzolanic effect contributed by metakaolin during early aging（3 days）; but the larger particle metakaolin and supplement of calcium and aluminum source may improve the medium-term（7days） strength of the paste.