CEMENT STABILIZATION OF DREDGED SEDIMENTS FROM DRAINAGE CANALS: EFFECT ON PHYSICO-CHEMICAL PROPERTIES

Abstract

Dredged sediments from drainage canals (canal dredged sediment; CDS) encountered significant challenges, particularly in Phetchaburi Province. This research focuses on the properties of CDS when stabilized with ordinary Portland cement (OPC). The sediments, characterized as silty sand with high water content and low compressive strength, were typically unsuitable for construction. In this study, air-dried CDS samples were treated with OPC at varying proportions of 150, 200, and 250 kg/m³, and initial water content of 14.32% and 17.00%, with curing times of 3, 7, 14, and 28 days. The investigation primarily centered on assessing the strength development using the unconfined compression test and evaluating the physico-chemical properties of cement-stabilized CDS through shear wave velocity (V_s) and suction tests. The findings revealed that the unconfined compressive strength (UCS) of the successful mixtures at 7 days of curing exceeded 689 kPa, indicating suitability for application as a subbase material. Moreover, the UCS consistently increased with the appropriate water-to-cement ratio and prolonged curing time, aligning with the trends observed in V_s measurements. A correlation between UCS and V_s tests is proposed based on the observed relationship. Furthermore, the suction tests revealed that the water content of cement-stabilized sediments was lower compared to natural soil, resulting in reduced volume strain changes upon mixing with cement. This underscores the potential of cement stabilization in enhancing the engineering utility of CDS, thereby supporting a sustainable waste management approach based on geo-environmental engineering practices.