膨润土膨胀特性与含水量关系研究

Study on the relationship between swelling characteristics and water content of bentonite

膨润土的膨胀特性与含水量密切相关。为获得两者的相关性,开展了不同初始含水量条件下无荷载膨胀率、有荷载膨胀率和膨胀力室内试验。试验研究结果表明:中等膨胀势膨润土在吸水饱和过程中无荷载膨胀率、有荷载膨胀率逐渐增大,且经历快速膨胀期、缓慢膨胀期和膨胀稳定期三个阶段;初始含水量越小,快速膨胀期历时越短,膨胀速率越快;随着初始含水量的增加,膨润土的无荷载膨胀率、有荷载膨胀率和膨胀力均呈减小趋势,且无荷载膨胀率、有荷载膨胀率随初始含水量线性递减,而膨胀力与初始含水量呈现良好负指数关系。

The swelling characteristics of bentonite is influenced significantly by initial water content. In order to search out the influential regularities of bentonite with medium swelling potentiality,the tests of swelling ratio without pressure, swelling ratio under pressure and swelling force under different initial water content are conducted. The experimental results show that： the swelling ratio without pressure and swelling ratio under pressure of bentonite increase gradually in the process of absorbing water and saturating,and swelling curves experience the rapid expansion,slow expansion and stable period; furthermore,the smaller initial water content is,the shorter rapid expansion period continues and the faster the swelling rate becomes; what＇s more,with the increase of initial water content,the swelling ratio without pressure,swelling ratio under pressure and swelling force are all in a trend of decrease; in addition,the experimental data demonstrate a linear negative correlation between swelling ratio without pressure,swelling ratio under pressure and the initial water content,and a good negative exponent relation between swelling force and the initial water content.