3D Printing of Cement-Based Materials Using Seawater for Simulated Marine Environments

Area of Science:

• Materials Science
• Civil Engineering
• Marine Engineering

Background:

• Rising global demand for offshore, coastal, and fluvial construction solutions.
• Increased investment in coastal infrastructure like energy platforms and seawalls.
• Need for adaptable and rapidly deployable construction methods.

Purpose of the Study:

• Investigate printable concrete mixtures using seawater for underwater 3D printing.
• Assess the effects of seawater and printing medium (in air vs. underwater) on concrete properties.
• Characterize rheological and mechanical performance for offshore applications.

Main Methods:

• Utilized a syringe-based extrusion system for 3D printing concrete.
• Formulated printable concrete mixtures with seawater replacing freshwater.
• Performed rheological and mechanical characterization (compressive and flexural strength, dimensional stability).

Main Results:

• Seawater adoption resulted in favorable rheological properties, including higher yield stress and viscosity.
• Seawater-based mixtures exhibited superior dimensional stability compared to freshwater mixtures.
• No statistical difference in compressive strength between in-air and underwater samples; flexural strength was influenced by geometry and printing medium.

Conclusions:

• Seawater is a viable component for printable underwater concrete mixtures, enhancing rheology and stability.
• Optimized curing strategies and layer bonding techniques are crucial for improving interfacial strength in underwater 3D printing.
• Findings provide critical parameters for developing printable underwater concrete for diverse marine applications.