黄泛区湖淤积高液限黏土的改性研究

在黄泛区高液限黏土中添加不同剂量的石灰、粉煤灰和石灰粉煤灰,通过液塑限试验探究材料液限、塑性指数随时间变化的规律,确定最优的改性剂量与效果。试验表明:黄泛区高液限黏土主要矿物含量为伊利石、蒙脱石及高岭石,亲水性好,液限在50%左右;具有膨胀性、易泡散、水稳定性差等缺点,浸水4 d的承载比(CBR)低于3%;二灰土中石灰外掺4%、石灰与粉煤灰配合比3:9均可降低材料的亲水性、膨胀性,提高水稳定性,在88%压实度下改性土4 d浸水CBR能达8%,满足路床区填料要求。

Study on modification of lake deposition high liquid limit clay in the Yellow River flood area

By adding different dosages of lime, fly ash and lime fly ash to the high liquid limit clay in areas formerly flooded by the Yellow River, the liquid-plastic limit test was conducted to investigate the law of material liquid limit and plastic index changing with the number of days, thereby determining the optimal modification dose and effect. The test showed that the main mineral content of high liquid limit soil in areas formerly flooded by the Yellow River was illite, montmorillonite and kaolinite, which had good hydrophily and a liquid limit of about 50%. It had expansibility, easy foaming nature, and poor water stability, with a bearing ratio (CBR) value of less than 3% after 4 d of water immersion; the addition of 4% lime and the 3:9 ratio of lime powder and coal ash in lime-fly ash soil could reduce the hydrophily and expansibility of the material, and improved water stability. The modified soil's CBR reached 8% under the 88% compaction rate after 4 d of water immersion, which met the filling requirements of roadbed area.