水泥改性膨胀土干密度与自由膨胀率试验研究

掺加一定比例的水泥对膨胀土进行改性是目前处理膨胀土的主要方法之一,通过在南水北调中线一期工程总干渠膨胀土试验段工程（南阳段）施工现场进行室内不同水泥掺量比的系列试验,研究不同水泥掺量、击实试验前后掺加水泥的膨胀土放置时间对水泥改性土干密度、自由膨胀率的影响,用以更好的指导工程施工。试验表明,随着水泥掺量的增大,水泥改性土的最大干密度逐渐减小;随着水泥改性土放置时间的增长,自由膨胀率逐渐变小并最终趋于稳定,水泥对膨胀土膨胀性的改良是一个渐进的、长时间的过程。

Experimental Study on Dry Density and Free Swelling Ratio of Cement-Treated Expansive Soil

Adding a certain proportion of cement is the popular methods to deal with the expansive .soil. Through a series of experiment with different cement ratios added into the expansive soil in the Middle Route of South-to-North Water Transfer Project Project construction (Nanyang Section) site, it studied the impact of construction on the dry density, free swelling ratio, storage time of cement-treated expansive soil before and after compaction test. Tests showed that, with the increasing adulterating quantity of cement, maximum dry density of cement-treated expansive soil decreased gradually; and with the growth of storage time of cement-treated expansive soil, free swelling ratio became smaller and smaller and eventually stabilized. Improvement of cement on the swelling of expansive soil is a gradual, long process.