Strength properties of a composite geomaterial for soft soil stabilization

The paper carries out an experimental investigation of strength properties of a composite geomaterial (CGM) composed of river dredged soils (RDS), ground granulated blast furnace slag (GGBFS), and waste fishing net (WFN). The experimental schemes are performed to examine the strength characteristics of CGM, encompassing unconfined compressive strength (UCS), California Bearing Ratio (CBR), and flexural strength. CGM specimens are prepared with various contents of GGBFS–RDS mixtures (5%, 10%, 15%, 20%, 30% and 40%) and two WFN contents (0.5% and 1%) for each GGBFS–RDS mixture. The experimental results indicate that the strength of CGM increases with an increase in curing time and influenced by content of each component in the mixture. The UCS and CBR of CGM increase as the GGBFS content increases from 0% to 15%, but decrease when the GGBFS content exceeds 15%. Although the CBR of mixtures with WFN inclusion is higher than that without WFN, the WFN does not significantly enhance the compressive strength in the UCS test. The WFN improves significantly the flexural strength and plays an important role in changes the brittle behavior into ductile response of CGM such as increase in axial strain at peak strength and maintain strength after failure state. An empirical relationship between UCS, CBR, and the secant modulus of CGM has been established, which is useful for practical engineering application.