EXPERIMENTAL STUDY OF THE MECHANICAL PROPERTIES OF BRICKS MADE FROM DREDGED SILT

Abstract

Numerous dredging and desilting projects in harbor and waterway transportation initiatives generate substantial quantities of dredged mud. Traditional methods, such as blowing and filling, occupy land resources and lead to secondary pollution. The offshore disposal of mud incurs high costs and environmental pollution. Consequently, this paper proposes a silt brick-making method devoid of sintering, autoclaving, and pressing. After a designated maintenance period, the silt bricks are examined to assess the influence of cement, initial moisture content, and age on their compressive and flexural strength. It is feasible to prepare silt bricks by mixing additive materials with silt, followed by molding, vibration, maintenance, demolding, and additional maintenance. As the age increases, the slope of the stress-strain curve for specimens at 1.0× and 1.5× the liquid limit increases accordingly. As the age increases, the slope of the stress-strain curve of the specimen increases, albeit not as rapidly as at 1.5× the liquid limit. The strain at failure remains consistent, primarily within the range of 2–3 %. Silt bricks containing cement-doped marine dredged sludge exhibit increased compressive and flexural strengths with higher cement doping levels, demonstrating a linear relationship between the two. Moreover, as the cement doping and maintenance age increase, the compressive modulus of silt bricks gradually increases, indicating an associated increase in brittleness. The research findings offer a theoretical framework for sintering-free, autoclaved, and pressed dredging silt bricks. This contributes to advancing offshore geotechnical disposal technology in China and holds reference value.