"A Century Seawall"

Black steel rebar is standard carbon-steel reinforcement (usually uncoated). 316 stainless steel rebar is a corrosion-resistant stainless alloy designed to perform in harsh, salty, and wet environments.

• Corrosion resistance (biggest difference):
   
  • Black steel: Rusts when chlorides (salt) and moisture reach it; rust expands and can crack/spall concrete over time.
     
  • 316 stainless: Highly resistant to rust and chloride attack, so it holds up far better in marine/coastal exposure.
     
• Service life & maintenance:
   
  • Black steel: More likely to drive future repairs in seawalls, caps, and splash zones.
     
  • 316 stainless: Often chosen to extend lifespan and reduce long-term maintenance/repairs.
     
• Cost:
   
  • Black steel: Lowest upfront cost.
     
  • 316 stainless: Higher upfront cost, but can be cheaper over the life of the structure in saltwater.
     
• Strength & behavior:
   
  • Both are strong and stiff, but 316 stainless typically has slightly different yield characteristics (often more ductile). In practice, designs follow the specified grade and engineer’s requirements.
     
• Best use cases:
   
  • Black steel: Interior concrete or low-chloride environments.
     
  • 316 stainless: Seawalls, coastal structures, splash/tidal zones, and any concrete exposed to saltwater or de-icing salts.ort description.

Fiberglass rebar (often called GFRP rebar) and black steel rebar both reinforce concrete, but they behave very differently—especially in marine/saltwater environments.

• Corrosion: Fiberglass rebar doesn’t rust, while black steel rebar will rust when moisture and salt reach it. Rust expands, which can crack/spall concrete and weaken the structure over time.
   
• Strength & stiffness: Fiberglass rebar can have high tensile strength, 2.5 to 3.5 times stronger than steel. Steel is stiffer, which helps control deflection. Until it rust.
   
• Longevity in saltwater: Fiberglass rebar is often chosen for seawalls and coastal work because it’s corrosion-resistant, while black steel typically needs more protection (more concrete cover, coatings, or other measures) to survive long-term.
   
• Weight & handling: Fiberglass rebar is much lighter, easier to carry, and often easier to cut; steel is heavier and usually requires more labor/tools.
   
• Electrical/magnetic: Fiberglass is non-conductive and non-magnetic; steel is conductive and magnetic.
   
• Cost: Black steel is often cheaper upfront, but fiberglass can be more cost-effective long-term where corrosion would otherwise cause repairs or early replacement.

A tieback is only as good as its ability to stay strong, stay protected, and keep transferring load for decades. That’s why it’s smart to sleeve the tieback in PVC and embed it in concrete at both ends:

• PVC sleeve = corrosion and damage protection. The PVC acts like a barrier that keeps saltwater, chlorides, and wet soil off the tieback (especially important in tidal or brackish areas). It also protects the rod/cable from abrasion against soil, shell, rocks, or debris, and helps reduce issues from stray-current corrosion/electrolysis.
   
• Concrete at both ends = permanent, reliable load transfer. A tieback works by pulling the seawall back against something solid. Encasing the connection points in concrete (at the seawall cap/waler end and at the deadman/anchor block end) creates a rigid “grip” that spreads the forces over a larger area, prevents shifting or pullout, and keeps the wall aligned.
   
• It prevents “weak links” where failures usually start. Most tieback problems happen at the connection points or along the buried section where corrosion, movement, and soil contact slowly eat away strength. PVC shielding plus concrete anchoring removes those common failure paths and greatly improves long-term performance.

 You need weep holes in a seawall because they let trapped groundwater escape in a controlled way, which relieves pressure behind the wall and prevents the soil from being forced out through the hole from the construction process. When it rains it prevents the rainwater from pushing fine sand and dirt through it. which leads to washouts, voids, and sinking behind the wall. A properly installed weep hole allows water to drain while keeping the soil in place, helping the seawall stay stable and protecting your yard from erosion.