Which Is Better, Steel or Aluminum Trench Shield?
Trench shields or trench boxes are usually made of steel or aluminum because both are strong and durable metals besides being abundant, recyclable, and cost-effective. In excavation and trenching works, steel and aluminum trench shield equally shares critical contribution in improving safety, quality, and productivity at construction sites. However, there are comparisons between the two with reference to their economical and overall performance.
The best way to understand or compare the two is possibly by establishing their features as raw materials and citing their pros and cons as finish products. It is important to dig into their features against the essentials of trench protection system like weight, cost, strength, and lifespan.
Strength to Weight Ratio
Aluminum has a tensile strength of 100 MPa and a density of 2.70g/cm3. Structural steel has a tensile strength of 350 MPa and a density of 8.0g/cm3.
Therefore, aluminum is lighter than steel. Steel is stronger than aluminum.
At same weight, aluminum is more expensive than stainless steel. However, aluminum is about 3X lighter than structural steel.
Therefore, at same volume, steel is generally cheaper but can be more expensive than aluminum at some point.
Grade 5052 aluminum is very soft or malleable. Grade 6061 is likely to crack if bent. Steel is less likely to warp or bend from force, impact, or heat.
Therefore, aluminum is weaker than steel and more prone to dents and scratches.
Aluminum has excellent corrosion resistance and does not rust. Aluminum alloys comes in different classifications such as 6061 and 5052 which is considered a marine grade. Structural steel with iron as main composition triggers oxidation when exposed to oxygen, thus, prone to rust.
Therefore, steel must be equipped with a superior coating system to inhibit good corrosion resistance next to aluminum.
Steel trench shield is typically 2X heavier than aluminum shield. Densit