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| report:soa [2026/06/13 13:46] – [2.5 Materials] team4 | report:soa [2026/06/14 23:22] (current) – [2.5.1. Structural Materials] team4 | ||
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| **Reef Design Lab** | **Reef Design Lab** | ||
| - | Reef Design Lab is an Australian design and fabrication company that develops artificial reef and marine habitat solutions. The company describes its work as the design, prototyping, | + | Reef Design Lab is an Australian design and fabrication company that develops artificial reef and marine habitat solutions. The company describes its work as the design, prototyping, |
| - | One of its well-known systems is MARS, which stands for Modular Artificial Reef Structure. MARS is a ceramic 3D-printed modular system designed to construct reef habitat without the need for heavy-duty equipment. The system can be deployed from small boats and assembled by divers, making it suitable for reef restoration projects in locations where large marine construction equipment may be difficult to use [(MARS2026)]. | + | One of its well-known systems is MARS, which stands for Modular Artificial Reef Structure. MARS is a ceramic 3D-printed modular system designed to construct reef habitat without the need for heavy-duty equipment. The system can be deployed from small boats and assembled by divers, making it suitable for reef restoration projects in locations where large marine construction equipment may be difficult to use [(ReefDesignLabMARS)]. |
| Figure {{ref> | Figure {{ref> | ||
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| This material incorporates bacterial spores, specifically *Bacillus sphaericus* (strain ATCC 14577), which remain dormant until a crack occurs. Water ingress activates the bacteria, which then precipitate calcium carbonate to seal the crack [(ALYAARI2026)]. | This material incorporates bacterial spores, specifically *Bacillus sphaericus* (strain ATCC 14577), which remain dormant until a crack occurs. Water ingress activates the bacteria, which then precipitate calcium carbonate to seal the crack [(ALYAARI2026)]. | ||
| - | | + | |
| - | * Cons: Higher complexity in mixing and requires specific nutrients like calcium lactate and urea [(ALYAARI2026)]. | + | * Pros: Achieves **96 % recovery in water tightness** within 56 days of seawater immersion [(ALYAARI2026)]. It maintains structural integrity above **100 MPa**, which is well above the hydrostatic |
| - | * Price: Estimated at **180 €/ | + | * Cons: Higher complexity in mixing and requires specific nutrients like calcium lactate and urea [(ALYAARI2026)]. |
| + | * Price: Estimated at **180 €/ | ||
| **B. Basalt Fiber-Reinforced Polymer (BFRP)** | **B. Basalt Fiber-Reinforced Polymer (BFRP)** | ||
| Basalt fibers, derived from natural volcanic rock, are used to reinforce concrete or as standalone composite laminates [(BasaltFiberMarine2025)]. | Basalt fibers, derived from natural volcanic rock, are used to reinforce concrete or as standalone composite laminates [(BasaltFiberMarine2025)]. | ||
| - | | + | |
| - | * Cons: Slightly lower peak flexural strength compared to glass fibers, although superior in long-term durability and environmental footprint [(BasaltFiberMarine2025)]. | + | * Pros: **Naturally non-corrosive** and chemically stable in aggressive saline environments [(BasaltFiberMarine2025)]. Vacuum infusion manufacturing can produce laminates with flexural strength up to **400 MPa** [(BasaltFiberMarine2025)]. It provides a more resilient, damage-tolerant failure mode compared to the brittle collapse of traditional reinforced concrete [(BasaltFiberMarine2025)]. |
| - | * Price: Estimated at **160 €/ | + | * Cons: Slightly lower peak flexural strength compared to glass fibers, although superior in long-term durability and environmental footprint [(BasaltFiberMarine2025)]. |
| + | * Price: Estimated at **160 €/ | ||
| **C. Geopolymer Gel Concrete** | **C. Geopolymer Gel Concrete** | ||
| A cement-free binder using materials like fly ash and metakaolin modified with nano-silica (SiO< | A cement-free binder using materials like fly ash and metakaolin modified with nano-silica (SiO< | ||
| - | | + | |
| - | * Cons: Higher production costs currently limit wide adoption [(LAI2026)]. | + | * Pros: Significantly **lower CO< |
| - | * Price: Estimated at **150 €/ | + | * Cons: Higher production costs currently limit wide adoption [(LAI2026)]. |
| + | * Price: Estimated at **150 €/ | ||
| **D. ECOncrete® / Sulfoaluminate Cement (SAC)** | **D. ECOncrete® / Sulfoaluminate Cement (SAC)** | ||
| A proprietary concrete mix designed to reduce surface alkalinity to a neutral pH [(SELLA2015)]. | A proprietary concrete mix designed to reduce surface alkalinity to a neutral pH [(SELLA2015)]. | ||
| - | | + | |
| - | * Cons: Requires specialized design to ensure the lower pH doesn' | + | * Pros: Surface **pH of 9–10** (closer to seawater |
| - | * Price: Estimated at **140 €/ | + | * Cons: Requires specialized design to ensure the lower pH does not compromise the protection of internal steel if used. |
| + | * Price: Estimated at **140 €/ | ||
| **E. Recycled Glass (Partial Aggregate Replacement)** | **E. Recycled Glass (Partial Aggregate Replacement)** | ||
| Crushed waste glass used to replace up to 30 % of fine aggregates in the concrete mix [(DAAROL2026)]. | Crushed waste glass used to replace up to 30 % of fine aggregates in the concrete mix [(DAAROL2026)]. | ||
| - | * Pros: Improves **chemical resistance** and reduces water absorption [(DAAROL2026)]. It offers an eco-friendly way to utilize waste while maintaining sufficient compressive strength for marine applications [(DAAROL2026)]. | ||
| - | * Cons: Replacing more than 30 % of aggregate leads to a **significant reduction in compressive strength** [(DAAROL2026)]. | ||
| - | * Price: Estimated at **90 €/ | ||
| + | * Pros: Improves **chemical resistance** and reduces water absorption [(DAAROL2026)]. It offers an eco-friendly way to utilize waste while maintaining sufficient compressive strength for marine applications [(DAAROL2026)]. | ||
| + | * Cons: Replacing more than 30 % of aggregate leads to a **significant reduction in compressive strength** [(DAAROL2026)]. | ||
| + | * Price: Estimated at **90 €/ | ||
| **F. Biorock (Mineral Accretion)** | **F. Biorock (Mineral Accretion)** | ||
| Uses low-voltage DC electricity to precipitate minerals (limestone) directly from seawater onto an iron frame. | Uses low-voltage DC electricity to precipitate minerals (limestone) directly from seawater onto an iron frame. | ||
| - | | + | |
| - | * Cons: Requires **constant power** from a buoy; if the power is interrupted, | + | * Pros: Accelerates biological growth by **400 %** and allows the structure to **self-repair** after impacts |
| - | * Price: Base infrastructure **120 €/ | + | * Cons: Requires **constant power** from a buoy; if the power is interrupted, |
| + | * Price: Base infrastructure **120 €/ | ||
| == 2.5.1.1 Comparative Table == | == 2.5.1.1 Comparative Table == | ||
| - | The previous subsection regarding the materials evaluated | + | The materials evaluated |
| < | < | ||
| <table tab: | <table tab: | ||
| - | < | + | < |
| - | | **Material** | + | ^ **Material** |
| - | | **Bacterial HSC** | Longevity/Pressure | + | | **Bacterial HSC** | Longevity / pressure resistance |
| - | | **Basalt Reinforcement** | Corrosion | + | | **Basalt Reinforcement** | Corrosion |
| - | | **ECOncrete®** | Marine-life | + | | **Geopolymer Gel Concrete** | Low carbon and chemical resistance | Lower CO< |
| - | | **Recycled Glass** | Sustainability | Increased chemical resistance | Strength loss > 30 % | 90–140 € | | + | | **ECOncrete®** | Marine-life |
| - | | **Biorock** | Life Promotion | + | | **Recycled Glass** | Sustainability | Increased chemical resistance | Strength loss above 30 % | 90–140 € | |
| + | | **Biorock** | Life promotion | ||
| </ | </ | ||
| </ | </ | ||
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| == 2.5.1.2 Materials for Prototype vs. Final == | == 2.5.1.2 Materials for Prototype vs. Final == | ||
| - | The final Maris Habitats product and the prototype have different material requirements because they have different purposes. The final product is intended for long-term underwater deployment, while the prototype is mainly used to validate the Reef Module | + | The final Maris Habitats product and the prototype have different material requirements because they have different purposes. The final product is intended for long-term underwater deployment, while the prototype is mainly used to validate the Reef Block shape, assembly process, Smartlogger attachment, and basic structural concept under controlled conditions. |
| - | For the final product, basalt fiber-reinforced concrete was selected as the intended material for the Reef Modules. This material was chosen because the final modules | + | For the final product, basalt fiber-reinforced concrete was selected as the intended material for the Reef Blocks. This material was chosen because the final Reef Blocks |
| - | For the prototype, the material selection was based on practicality, | + | For the prototype, the material selection was based on practicality, |
| During the prototype planning stage, three material options were considered: | During the prototype planning stage, three material options were considered: | ||
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| **Option 1: Polymer clay model** | **Option 1: Polymer clay model** | ||
| - | Polymer clay was considered during the early design stage because it can be shaped by hand and hardened in an oven. This makes it useful for quick form exploration when the team needs to test different shapes before deciding on the final Reef Module | + | Polymer clay was considered during the early design stage because it can be shaped by hand and hardened in an oven. This makes it useful for quick form exploration when the team needs to test different shapes before deciding on the final Reef Block geometry. Polymer clay remains soft until it is baked, and baking is used to cure the material so that the shape becomes hard [(SculpeyBaking)]. It can also be stretched, cut, rolled, molded, stacked, and sculpted before baking, which makes it practical for small visual models and early design tests [(SculpeyOvenBakeClay)]. |
| - | However, polymer clay was not selected as the main prototype material because it is very different from the final concrete-based product. It cannot represent the real weight, concrete surface texture, porosity, or handling of the final Reef Module. It is also limited by oven size and is not suitable for validating structural performance, | + | However, polymer clay was not selected as the main prototype material because it is very different from the final concrete-based product. It cannot represent the real weight, concrete surface texture, porosity, or handling of the final Reef Block. It is also limited by oven size and is not suitable for validating structural performance, |
| * **Pros:** Easy to shape, easy to modify before baking, low cost, and useful for early form exploration. | * **Pros:** Easy to shape, easy to modify before baking, low cost, and useful for early form exploration. | ||
| - | * **Cons:** Very different from the final concrete-based material, limited by oven size, does not represent real Reef Module | + | * **Cons:** Very different from the final concrete-based material, limited by oven size, does not represent real Reef Block weight, texture, porosity, or handling, and is not suitable for technical validation. |
| - | + | ||
| - | + | ||
| **Option 2: Cement-based prototype cast with a 3D-printed mold** | **Option 2: Cement-based prototype cast with a 3D-printed mold** | ||
| - | A cement-based prototype is closer to the final concrete-based product because it can better represent the general appearance, surface texture, weight, and handling of the Reef Module. Concrete is widely used for artificial reef construction and can be used to create complex shapes for marine habitat structures [(ArtificialReefPreparation2026)]. In this approach, PLA filament is used to produce a 3D-printed mold, and cement is poured into the mold and left to cure. Therefore, PLA is not used as the final material of the Reef Module | + | A cement-based prototype is closer to the final concrete-based product because it can better represent the general appearance, surface texture, weight, and handling of the Reef Block. Concrete is widely used for artificial reef construction and can be used to create complex shapes for marine habitat structures [(ArtificialReefPreparation2026)]. In this approach, PLA filament is used to produce a 3D-printed mold, and cement is poured into the mold and left to cure. Therefore, PLA is not used as the final material of the Reef Block prototype, but as a tooling material for shaping the cement-based model. PLA is suitable for this purpose because it is commonly used for rapid prototyping and can also be used for mold inserts or casting-related applications [(PrusaPLA)], [(UltiMakerPLA)]. |
| - | This option allows the team to combine the geometric accuracy of 3D printing with the more realistic material behavior of a cement-based prototype. It is also low-cost and possible to produce locally. However, the prototype is not intended for real underwater deployment, and normal cement does not fully represent the final basalt fiber-reinforced concrete. Therefore, this option can be used to check the general shape, handling, assembly, and Smartlogger attachment, but it cannot prove long-term durability or full structural performance in marine conditions. For the final product, basalt fiber-reinforced concrete would still be required because it is more suitable for long-term marine exposure and resistance to chemical and environmental degradation [(BasaltFiberMarine2025)][(QU2021)]. | + | This option allows the team to combine the geometric accuracy of 3D printing with the more realistic material behavior of a cement-based prototype. It is also low-cost and possible to produce locally. However, the prototype is not intended for real underwater deployment, and normal cement does not fully represent the final basalt fiber-reinforced concrete. Therefore, this option can be used to check the general shape, handling, assembly, and Smartlogger attachment, but it cannot prove long-term durability or full structural performance in marine conditions. For the final product, basalt fiber-reinforced concrete would still be required because it is more suitable for long-term marine exposure and resistance to chemical and environmental degradation [(BasaltFiberMarine2025)], [(QU2021)]. |
| * **Pros:** Similar appearance to the final material, more realistic weight and texture, accurate geometry from the 3D-printed mold, low cost, and suitable for checking general shape, handling, assembly, and Smartlogger attachment. | * **Pros:** Similar appearance to the final material, more realistic weight and texture, accurate geometry from the 3D-printed mold, low cost, and suitable for checking general shape, handling, assembly, and Smartlogger attachment. | ||
| * **Cons:** Does not fully represent basalt fiber-reinforced concrete, harder to modify after casting, requires curing time, and is not suitable for proving long-term marine durability because the prototype is only intended for controlled testing. | * **Cons:** Does not fully represent basalt fiber-reinforced concrete, harder to modify after casting, requires curing time, and is not suitable for proving long-term marine durability because the prototype is only intended for controlled testing. | ||
| - | |||
| - | |||
| **Option 3: Fully 3D-printed scale model or 3D-printed details** | **Option 3: Fully 3D-printed scale model or 3D-printed details** | ||
| - | A fully 3D-printed model can represent the geometry of the Reef Module, Smartlogger, | + | A fully 3D-printed model can represent the geometry of the Reef Block, Smartlogger, |
| - | However, this option means that the Reef Module | + | However, this option means that the Reef Block itself is made from 3D-printed plastic rather than cement or concrete. Because of this, the material properties are different from the final concrete-based product. A fully 3D-printed plastic model cannot represent the real weight, concrete surface texture, porosity, or marine durability of the final Reef Block. Therefore, it is useful for geometry and assembly validation, but not for checking realistic handling, seabed stability, or material behavior. |
| - | In the selected prototype approach, 3D printing is used mainly to produce the PLA mold for cement casting, rather than to make the final Reef Module | + | In the selected prototype approach, 3D printing is used mainly to produce the PLA mold for cement casting, rather than to make the final Reef Block prototype itself. Additional 3D-printed parts may still be used for small details or Smartlogger attachment features that require accurate geometry. |
| * **Pros:** Accurate geometry, easy to modify, fast to produce, suitable for assembly checks, Smartlogger attachment tests, packaging checks, and presentation. | * **Pros:** Accurate geometry, easy to modify, fast to produce, suitable for assembly checks, Smartlogger attachment tests, packaging checks, and presentation. | ||
| - | * **Cons:** Different from the final material, does not represent real module | + | * **Cons:** Different from the final material, does not represent real Reef Block weight, concrete surface texture, porosity, or marine durability, and is not suitable for material durability or seabed stability testing. |
| - | === 2.5.2 Sensor | + | === 2.5.2 Sensor |
| Designing a successful marine habitat involves a delicate technical paradox. On one hand, the project’s primary objective is to encourage biological colonization and the growth of marine life; on the other, the integrated sensors require direct, unobstructed contact with seawater to maintain accuracy. This necessity creates a significant challenge, as the very " | Designing a successful marine habitat involves a delicate technical paradox. On one hand, the project’s primary objective is to encourage biological colonization and the growth of marine life; on the other, the integrated sensors require direct, unobstructed contact with seawater to maintain accuracy. This necessity creates a significant challenge, as the very " | ||
| - | To resolve this conflict, the strategy focuses on three integrated design pillars. First, a careful selection of housing materials must be made to support structural durability while protecting the internal components. Second, | + | To resolve this conflict, the strategy focuses on three integrated design pillars. First, a careful selection of housing materials must be made to support structural durability while protecting the internal components. Second, specialized |
| When positioning sensors, it is important to consider factors that may influence measurement accuracy, such as turbulence and disturbed flow conditions. Careful placement can significantly improve the reliability and consistency of the collected data. | When positioning sensors, it is important to consider factors that may influence measurement accuracy, such as turbulence and disturbed flow conditions. Careful placement can significantly improve the reliability and consistency of the collected data. | ||
| - | The Smartbox, which contains the sensors, is mounted at the top of the supporting structure | + | |
| + | The Smartlogger, which contains the sensors, is mounted at the top of the Smartlogger attachment | ||
| Instead, the sensors are preferably mounted on a side surface where there is sufficient and consistent water flow. Positioning them slightly above the seabed further reduces the risk of sand and sediment deposition, ensuring more stable and accurate measurements. This placement also allows the surrounding water to circulate more freely around the sensors, which is particularly important for measurements such as conductivity, | Instead, the sensors are preferably mounted on a side surface where there is sufficient and consistent water flow. Positioning them slightly above the seabed further reduces the risk of sand and sediment deposition, ensuring more stable and accurate measurements. This placement also allows the surrounding water to circulate more freely around the sensors, which is particularly important for measurements such as conductivity, | ||
| - | In addition, the Smartbox is positioned to be as accessible as possible to facilitate maintenance operations, such as sensor cleaning, battery replacement, | ||
| + | In addition, the Smartlogger is positioned to be as accessible as possible to facilitate maintenance operations, such as sensor cleaning, battery replacement, | ||
| == 2.5.2.1 Materials for Housing == | == 2.5.2.1 Materials for Housing == | ||
| - | The housing material must protect the internal electronics from high pressure and corrosion while maintaining long-term durability in seawater environments. | + | The Smartlogger |
| - | **Titanium alloy (TC4)** or **316 L stainless steel** are recommended for pressure resistance and durability [(SAHOO2025)]. For more than 200 m depth, **Titanium** | + | **Titanium alloy (TC4)** or **316 L stainless steel** are recommended for pressure resistance and durability [(SAHOO2025)]. For deeper or long-term deployments, titanium can be considered because it is described as a corrosion-resistant housing material suitable |
| == 2.5.2.2 Antifouling Coatings == | == 2.5.2.2 Antifouling Coatings == | ||
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| Even with durable housing materials, marine organisms may attach to exposed surfaces over time. For this reason, antifouling coatings are considered to reduce biological growth on sensors and maintain measurement accuracy. | Even with durable housing materials, marine organisms may attach to exposed surfaces over time. For this reason, antifouling coatings are considered to reduce biological growth on sensors and maintain measurement accuracy. | ||
| - | | + | * **Polydimethylsiloxane (PDMS):** A non-toxic, " |
| - | * | + | * **Camptothecin (CPT)-based Paint:** A natural compound that has shown virtually no macrofouling after nine months of immersion [(SAHOO2025)]. |
| - | * | + | * **Slippery Liquid-Infused Porous Surfaces (SLIPS):** These provide exceptional resistance to organism attachment even in stagnant water [(SAHOO2025)]. |
| - | + | === 2.5.3 Biologic and Geographical | |
| - | + | ||
| - | === 2.5.3 Biologic and geographical | + | |
| **Fish structure** | **Fish structure** | ||
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| ==== 2.6 Summary ==== | ==== 2.6 Summary ==== | ||
| - | Chapter 2 gives an overview of existing artificial reef concepts, relevant companies, material choices, sensor challenges, and biological and geographical factors. It shows that Maris Habitats differs from many existing solutions by combining modular | + | |
| + | Chapter 2 gives an overview of existing artificial reef concepts, relevant companies, material choices, sensor challenges, and biological and geographical factors. It shows that Maris Habitats differs from many existing solutions by combining modular | ||