Performance Testing
Flexural Test of Reinforced Concrete Specimens
This study evaluated the flexural performance of 3D-printed reinforced concrete (RC) seawall panels produced by Kind Designs. The objective was to confirm that 3D printing techniques can deliver structural strength equivalent to or greater than that of standard precast seawall panels.
Tests performed at the University of Miami’s Structures and Materials Laboratory, evaluated the load capacity, failure mechanisms, and material behavior of 3D-printed seawall panels relative to traditional precast concrete designs. The results confirmed that Kind Designs’ 3DCP (3D Concrete Printed) panels meet the structural performance requirements for standard seawall applications—validating 3D printing as a viable, code-compliant manufacturing method for marine infrastructure.
Research Objectives
Verifying Strength and Safety of 3D-Printed Marine Infrastructure
The primary objectives of this study were to:
- Quantify the flexural strength and stiffness of 3D-printed RC panels.
- Compare structural performance to conventional precast seawall panels.
- Characterize failure modes (cracking, deflection, and strain distribution).
- Validate 3D printing technology for marine-grade structural components.
Ultimately, this research confirms that innovative fabrication methods can deliver durable, code-compliant, and structurally robust seawalls suitable for long-term coastal protection.
Methodology
Laboratory Evaluation at the University of Miami Structures and Materials Lab
Testing followed ISO 17025-17 laboratory best practices for flexural tests of reinforced concrete elements.
Test Setup
- Configuration: Symmetric three-point bending using a universal test frame compliant with ASTM E4-21 (Standard Practices for Force Verification of Testing Machines).
- Loading: Monotonic single-cycle load applied to failure under displacement control at 3.5 mm/min (0.14 in/min).
- Instrumentation:
- LVDTs measured deflection at supports and midspan (verified under ASTM E83-23).
- Inclinometers tracked end rotations.
- Strain gauges measured compressive strain in both the 3D-printed shell and the infill concrete at midspan.
- All data were recorded through an integrated National Instruments acquisition system.
- Visual Monitoring: A surface grid was applied to document crack initiation and propagation.
- Testing Location: University of Miami, College of Engineering – Structures and Materials Lab, Coral Gables, FL.
Specimens
- Quantity: Five (5) RC slabs.
- Designs:
- One control slab (four horizontal steel bars; no 3D-printed shell).
- Four 3D-printed slabs—two with four bars and two with six bars.
- Dimensions: 3048 mm (10 ft) long × 711 mm (28 in) wide × 203 mm (8 in) thick.
- Effective test span: 2438 mm (8 ft).
- The compressive (top) layer of the specimen was composed of the 3D printed concrete, i.e. shell.
- Conditioning: Specimens tested as received under standard lab conditions.
- Identification: Labeled per test protocol (MM_RR_XX), where RR denotes reinforcement configuration.
Key Findings
3D-Printed Panels Meet and Exceed Structural Performance Targets
Target Flexural Strength: 600–1000 psf (2929–4882 kg/m²) – including a safety factor of 2.
Measured Result:
- 3D-Printed Panels: 938 psf (4580 kg/m²) — PASS
- Performance: Exceeded minimum structural requirements for seawall panels 10–12 ft in height.
Observations during testing showed ductile failure modes, controlled cracking behavior, and load-deflection profiles comparable to or better than standard precast panels.
Practical Applications
Structural Validation for 3D-Printed Coastal Infrastructure
Testing confirmed that Kind Designs’ 3D-printed Living Seawalls™ are structurally equivalent to conventional precast seawall panels and meet the performance standards expected for code-compliant coastal defense structures.
These findings validate that additive manufacturing can produce large-scale, load-bearing marine infrastructure that is both structurally sound and environmentally beneficial—opening the door for broader adoption of sustainable construction methods in coastal engineering.
Ongoing Research
Advancing Non-Corrosive Reinforcement and Material Systems
Kind Designs is continuously testing non-ferrous and composite reinforcement systems to identify cost-effective, high-performance alternatives to steel that resist corrosion in marine environments.
These studies aim to further extend the lifespan, sustainability, and resilience of 3D-printed seawalls—ensuring structural reliability alongside environmental compatibility.