Investigation on strength behavior of cemented dredged clay with straw at various curing stages

Abstract

Dredged clay with high water is difficult to use directly in practical engineering due to its extra-low strength. So, a solidifying treatment is often used to improve its engineering properties. In this study, a number of unconfined compression shear tests were conducted to investigate the strength behavior of cemented dredged clay with straw at different curing stages. For cemented dredged clay cured for a few days, the addition of filamentous straw and powdered straw would enhance its unconfined compressive strength (q u). Then, a decrease in q u is observed for samples with a small straw content as the curing time increases, mainly due to the deterioration of the straw. However, solidified soil amended by granular straw sees its q u decreases with increasing straw content decreasing its compactness and integrity. In addition, the failure strain (ε f) varies mostly within the range of (1.0% and 4.0%) and basically decreases with the increasing curing time and straw content. For the cemented dredged clay used in this research, the straw less than 6 mm with a ratio of sample diameter-to-straw length greater than 6.7 is helpful for improving the early-stage strength behavior when the straw content is less than 8%.