Splitting tensile strength behavior of dredged sediment with cement stabilization and straw fiber reinforcement

Abstract

This study investigated the splitting tensile strength behaviors of dredged sediment (DS) with Portland cement (PC) stabilization and straw fiber (SF) reinforcement. A series of splitting tensile strength (STS) tests were conducted to explore the STS and associated tensile stress–strain evolutions of PC-stabilized and SF-reinforced DS (CSFDS) under influences of PC content, SF content, SF length, and water content. In addition, the coupling action between PC stabilization and SF reinforcement inside CSFDS was clarified. The results show that incorporating SF weakened the STS of cement-stabilized DS (CDS), and the optimum SF content and length were, respectively, determined to be 0.4% and 2–5 mm. Incorporating suitable amount of SF could obviously alleviate the brittleness characteristics of CDS, and CSFDS exhibited strain-hardening characteristics under SF content of 0.2–0.6%. The effective empirical STS prediction model of CSFDS that comprehensively considers the influence of multiple factors was established. The “bridge effect” of SF inside CSFDS was beneficial for the ductility improvement, while the porous properties of SF and the wetting and erosion effects may be the intrinsic cause of strength decline of CDS with incorporating SF. The key findings can advance the recycling of CSFDS in geotechnical engineering applications and the collaborative resources utilization of DS and SF.