摘要
采用新型非接触式电阻率测定仪和椭圆环收缩开裂试验装置,分别测试了粉煤灰复合水泥浆体早期电阻率及粉煤灰复合水泥砂浆的初始开裂时间。结果表明:掺粉煤灰的水泥基材料早期电阻率变化与其水化过程和微结构形成以及开裂敏感性有着密切联系,随着粉煤灰掺量的增加,电阻率曲线上硬化特征点推迟,粉煤灰的延迟水化硬化作用降低了砂浆的早期开裂敏感性,在干燥条件下,粉煤灰砂浆的初始开裂时间显著延长;然而,为了确保适宜的早期强度增长率和其它技术性能的要求,粉煤灰掺量需适当控制。
Electrical resistivity and initial cracking time of composite cement mortar materials mixed with fly ash were measured using an non-contacting resistivity meter and ellipse-ring cracking apparatus with an automatic monitoring system respectively. The result shows there are close relationships between early resistivity change and hydration process as well as cracking sensitivity of composite cement mortar materials mixed with and without fly ash. With the increase of fly ash(FA) content, cracking sensitivity of fly ash mortar is decreased due to the delay of feature point of hardened structure in resisitivity curve. However, the limited fly ash content is favorable for other properties of composite cement mortar materials mixed with fly ash.
出处
《长江科学院院报》
CSCD
北大核心
2005年第2期43-46,共4页
Journal of Changjiang River Scientific Research Institute
基金
武汉大学创新基金资助(206270033)
关键词
粉煤灰
电阻率
开裂敏感性
收缩
fly ash
resistivity
shrinkage
cracking sensitivity
