Abstract

Cement-based treatment is a well-established technology for converting unwanted marine dredged clay (MDC) to qualified filling materials. However, a basic understanding of the strength development of cement-treated MDC is still lacking. In this study, we attempt to characterize the strength variation of cement-treated MDC under a wide range of water-to-cement ratios (w/c). The dominant influencing factors such as initial water content, cement content, curing time and pore salinity are examined through a series of laboratory tests. The results indicate that the strength of cement-treated MDC decreases exponentially with the initial water content. The strength approaches zero when the initial water content increases to 3.5–4.0 times the liquid limit, even with a high content of cement. The effect of pore salinity depends significantly on the cement content and curing time. Owing to the wide range of w/c, the extensively used Abrams’ law fails to characterize the strength variation of cement-treated MDC precisely. To this end, a new strength prediction model is proposed based on the concept of minimum cement content. The volume ratio is found to be inferior to the mass ratio in defining the minimum cement content, which remains approximately constant even for a wide range of w/c.

摘要

水泥基处理是一项成熟的技术，可将不需要的海洋疏浚粘土 (MDC) 转化为合格的填充材料。然而，对于水泥处理的 MDC 的强度发展仍然缺乏基本的了解。在这项研究中，我们试图表征在各种水灰比（w/c）下水泥处理的 MDC 的强度变化。）。通过一系列的实验室测试，检验了初始含水量、水泥含量、养护时间和孔隙盐度等主要影响因素。结果表明，水泥处理过的MDC的强度随着初始含水量呈指数下降。当初始含水量增加到液限的 3.5-4.0 倍时，即使水泥含量很高，强度也接近于零。孔隙盐度的影响很大程度上取决于水泥含量和养护时间。由于w/c范围广泛，广泛使用的艾布拉姆斯定律无法精确表征水泥处理的 MDC 的强度变化。为此，基于最小水泥含量的概念，提出了一种新的强度预测模型。在定义最小水泥含量时，发现体积比不如质量比，即使对于很宽的水灰比范围，最小水泥含量也保持近似恒定。