Study on mechanical properties of dredged silt stabilized with cement and reinforced with alginate fibers

Abstract

Based on the qualities of environmental protection and metal adsorption, alginate fibers were utilized as new curing agents to reinforce cement stabilized dredged silt. The influences of fiber content (0%, 0.3%, 0.6%, and 0.9% by weight of wet soil), cement content (6%, 9%, and 12% by weight of wet soil), and curing time (7, 14, 28and 60 days) on compressive strength were investigated by unconfined compressive strength test, and the reinforcement mechanism of alginate fibers was analyzed. A modified model by considering the parameters including moisture content of soil, curing time, content and length of alginate fibers, and cement content for predicting compressive strength were established. The experimental results revealed that the failure mode of alginate fibers reinforced cement stabilized soil changed from brittle failure to ductile failure with the increasing content and length of alginate fibers. Moreover, the unconfined compressive strength of the sample was improved with the increasing content and length of alginate fibers. However, the content of alginate fibers is 0.6%, length is 3 mm, which can be used as the optimum content and length determined by analyzing the strength growth rate for alginate fibers reinforced cement stabilized soil. Finally, the strength values of modified model were compared with the measured strength values, it was found that the calculated results of this model were within 20% of the measured results, which can be used for engineering strength prediction.