粉煤灰水泥浆体孔溶液中K^+、Na^+和OH^-离子的表征

Characterization of Na^+,K^+ and OH^- ions in the pore solutions of cement pastes with fly ashes

采用挤压法提取了水泥浆体的孔溶液,利用火焰光度计和pH计分别检测了孔溶液中Na+、K+和OH-离子的浓度。利用电子天平测定了不同养护环境下水泥浆体的质量变化率。对水泥水化试样做了SEM和DSC-TG分析。分析表明,孔溶液中OH-浓度的高低是由K+和Na+离子的浓度决定的,Na+、K+和OH-离子起到了火山灰活性激发剂的作用,且K+离子的浓度的变化程度较Na+的大。在水化早期,水养护粉煤灰水泥浆体孔溶液的Na+、K+和OH-离子浓度的降幅较硅酸盐水泥浆体的大。

The extrusion method was used for getting pore solutions of cement pastes.Flame photometer and pH meter was used to detect the concentrations of Na＋,K＋ and OH-ions in the pore solutions.Electronic Balance was used to measure the weight variation rate of cement paste blocks in two different curing conditions.And the analysis of SEM and DSC-TG of the hydrated cement pastes was made.Results showed that the level of concentration of OH-ion is determined by the level of the concentration of K＋ and Na＋ ions,the Na＋,K＋ and OH-ions in the pore solutions has played a role of active agent for the fly ash,but the changing extent of the concentration of K＋ ion is more significant than Na＋ ion.The reducing extent of Na＋,K＋ and OH-in pore solutions of cement pastes with fly ashes at early age is greater than the Portland cement paste when it was cured in water.