Components of Our Fabric Buildings
All our structures are assembled from components made of a steel alloy with zinc and nickel corrosion protection. This composition ensures high-quality bolting that will maintain the integrity and durability of the structure.
Our experts have conducted numerous tests and analyses to evaluate the resistance of our components in corrosive environments. These tests ensure compliance with ASTM F2329, which sets the standards for the application of zinc protection and/or hot-dip galvanization on components (bolts, nuts, etc.).
The specifications cover the chemical composition of the zinc, coating thickness, finish, appearance, and adhesion.
Structures
Structural steel
| Structural Steel used by MegaDome | Commercial Steel | |
|---|---|---|
| Yield Strength | Minimum of 50,000 PSI | Between 33,000 and 60,000 PSI (inconsistent from batch to batch) |
| Steel Chemistry | Fixed and validated with mill certificates for each tube | Variable and unverified |
| Standardized | Yes | No |
| Anticipation of Steel Reactions to Wind and Snow Loads | Yes | No |
Oval tubes
Several years of research and testing conducted at our factory have shown that this type of welding is fully compatible with the pre-galvanized steel coating and makes it much more resistant to corrosion than conventional welding.
| Bronze Welding | Conventional Welding |
|---|---|
| Harnois is the only company accredited in Canada to weld structures with bronze. | Molten steel burns the protection and contaminates the weld. |
| Unique expertise in welding pre-galvanized steel structures without altering the galvanization. | The galvanization mixes with the weld, reducing its quality and strength. |
| The weld and surrounding area resist corrosion and do not rust. | Over time, the weld rusts, weakens, and loses its ability to support the structure. |
| All welds are approved by the company's engineers. | Welds can be painted, but the protection offered by the paint is very limited. |
Corrosion protection
The lower section of the arches is always hot-dip galvanized after welding. This part of the arch, which serves as the critical link between the structure and the foundation, is more exposed to dust and corrosive elements. This galvanization ensures the protection of the steel and the durability of the structure.
The rest of the structure is made from pre-galvanized steel (EzDome and DB series). This galvanization process is done before transformation. The original sheets pass through a bath of molten zinc just before being formed and welded into long, uniform tubes. These tubes are then cut and welded at our manufacturing facility to become components of MegaDome buildings.
The entire structure of the AR series is hot-dip galvanized.
Oval Steel Tubes
- The welds benefit from a larger surface area (membrane) compared to round tube welds (except for the EZ Series buildings, which have no welds)
- An ovalized tube is stronger than a round or rectangular tube of similar size, resulting in a more efficient structure that requires less steel;
- This tube shape can withstand higher compression forces than an equivalent gauge rectangular or square tube;
- This type of tube has no edges, eliminating friction points and preventing premature wear that might occur with square or rectangular tubes. The ovalized tube thus contributes to the membrane's longevity.
Cover
The PowerShield® membrane is the most advanced polymer technology on the market. Waterproof and durable, this premium covering is engineered and designed to protect your valuable assets from the elements.
The PowerShield® membrane is manufactured in our factory, where our expert team assembles large strips of fabric into a single piece using a hot welding process. Rigorous quality controls are conducted throughout production to ensure thickness, weld strength, and color uniformity, resulting in a homogeneous and high-quality final fabric.
The PowerShield® membrane allows the easy prenetration of natural light, allowing our clients to enjoy the benefits of a bright space and significant daytime energy savings.
For industrial projects, you have the option to choose a membrane with a fire-retardant additive, compliant with Building Code standards. This additive prevents the membrane from acting as an accelerant and reduces the risk of fire spreading.
We produce PowerShield® membrane that meets the specific needs of livestock farmers. It allows 30 percent more light penetration.This special feature contributes to a brighter, cleaner and safer environment by promoting solar sterilization, a process which can generate significant savings on veterinary fees. Humidity will also be lower with this membrane in comparison with the standard membrane.