钢渣改良膨胀土试验效果与机理分析

对膨胀土、石灰改良膨胀土、钢渣微粉改良膨胀土进行干湿循环试验、自由膨胀率试验、无侧限抗压强度试验,比较验证钢渣微粉对膨胀土的改良效果。试验结果表明:钢渣微粉对膨胀土干湿循环作用下裂隙的发展、自由膨胀率的减小、强度的增加均有明显改善效果。其中钢渣微粉对自由膨胀率的改良效果明显滞后于石灰,但最终的改良效果两者相近,强度改良效果钢渣微粉明显优于石灰。同时运用X射线能谱的方法对膨胀土、石灰改良膨胀土、钢渣微粉改良膨胀土进行矿物成分和化学组成分进行分析,发现钢渣微粉改良膨胀土与石灰改良膨胀土矿物成分相近结合,自由膨胀率和无侧限抗压强度试验结果,对比分析得出钢渣微粉改良膨胀土和石灰改良土在改良机理上有相似性。

Experiments and mechanism of slag improving expansive soil

The dry-wet cycling test, the free expansion rate test, unconfined compressive strength test are carried out for the expansive soil, lime improving expansive soil, the steel slag fine powder modified expansive soil to compare and verify the modified effect.The results show that the steel slag fine powder has improved significantly effect on the action of the expansive soil dry-wet circulation development of crack, the reduction of free expansion rate, the increase of strength.Among them, the modified effect of steel slag fine powder to free expansion rate is obviously behind the lime, but the ultimate improvement effect is similar.Strength improvement of steel slag fine powder is superior to lime. With the method of X-ray energy spectrum, the mineral composition and chemical composition of the expansive soil, lime improving expansive soil and the steel slag fine powder modified expansive soil are analyzed.The conclusion is that the mechanism of modifying expansive soil by steel slag fine powder is similar to the lime.