矿物掺合料及硫酸钠对混凝土早期电导率的影响

目的研究混凝土中掺入粉煤灰、矿渣微粉及硫酸钠的电导率变化规律.方法利用电导率仪,测定混凝土从成型开始48h电导率的变化规律.结果硫酸钠的掺入使水泥混凝土电导率峰值滞后;随着粉煤灰、矿渣微粉掺量的增加,混凝土的电导率呈下降趋势;而加入硫酸钠后,粉煤灰电导率随掺量增加而增加,矿渣微粉电导率整体规律并无变化.结论电导率曲线表明了硫酸钠对普通水泥除具有缓凝作用外,还为其早强作用提供了新证据;矿物掺合料的活性低于水泥且矿渣微粉的活性高于粉煤灰,硫酸钠对粉煤灰及矿渣微粉具有较好的激发作用.

Influence of Mineral Admixture and Sodium Sulfate on Early Concrete Electric Conductivity Rate

The paper aims to investigate the influence of different quantity of fly-ash,pulverized slag and sodium sulfate on concrete electric conductivity rate.The electric conductivity rate instrument was used to measure the variational regulation of the 48 early electric conductivity rate.The result demonstrates that the peak value of cement concrete electric conductivity rate was delayed after sodium sulfate was added.The concrete electric conductivity rate tends to reduce with the quantity of fly-ash and pulverized slag increasing,however,with increasing quantity,the electric conductivity rate of the concrete mixed with fly-ash increases which mixed with pulverized slag has no change when there is added with sodium sulfate.The retarding function of sodium sulfate to cement is indicated by the curve of electric conductivity,which also provides new evidence of accelerating hardening.The activity of mineral admixture is lower than that of cement but the activity of pulverized slag is higher than that of fly-ash.Sodium sulfate has good activited effect on fly-ash.