Study Geopolymer from Dredged Sediment, Fly Ash, and Caustic Soda using the Taguchi Experimental Planning Method

Abstract

In this study, the Taguchi experimental planning method was employed to evaluate the influence of three factors – dredged sediment content (30-70 wt.%), waste ceramic wool content (3-7 wt.%), and NaOH concentration in the alkaline activator solution (8-14 M) – on the compressive strength of geopolymer mortar prepared with sea sand, brine, and hydrothermal curing. The results indicated that lower sediment content and moderate levels of ceramic wool and NaOH concentration within the investigated ranges enhanced compressive strength. A regression model was developed to predict compressive strength, demonstrating good agreement with experimental values. Based on the model, the maximum allowable dredged sediment content to achieve compressive strengths of 3.5 MPa and 20 MPa – corresponding to low- and high-strength grades according to the Vietnam national standard TCVN 6477:2016 for concrete bricks – was found to be 70 wt.% and 39 wt.%, respectively. This approach presents a promising solution for the sustainable treatment of dredged sediment while meeting construction performance requirements.