Marine Structures

Reinforced concrete coastal structures (wharfs and pier decks) are highly susceptible to chloride attack as a result of continuous exposure to airborne sea spray, especially in the splash zone where there is sufficient oxygen to facilitate corrosion.

The intermittent wet and dry conditions intensify the damage as chloride ions readily penetrate even dense concrete, initiating corrosion of the steel reinforcement (rebar). This attack results in cracks and spalling, which necessitates very costly and major repairs.

Marine structures also suffer from freeze/thaw damage in some climates, and abrasion damage due to heavy traffic e.g. in container ports.

Continuous and aggressive action of waves and currents affords only a small window of opportunity to repair many defects and provide lasting protection for marine structures.

Substructure – Concrete Repair

In restoration projects the concrete surface maybe deteriorated (eroded) to varying depths and requires surface repair. The condition of the surface is sometimes only found after a suitable surface preparation is carried out.

Surface Preparation

Clean the reprofiled surface using 34 MPa (5,000 psi) pressure water, or sandblast, to obtain minimum CSP #3 per ICRI (International Concrete Repair Institute).

Corrosion Protection – Fibre-Prime

Clean reinforcing steel using mechanical abrasion – “white metal” surface is NOT required.

Polymer modified cementitious rustproofing, with migrating corrosion protection technology, is applied in 2 coats over exposed rebar surface to protect partially “buried” steel, to provide protection from future rusting.

Thin Reprofiling – up to 12 mm (1/2”) – Gem-Plast TC

Spray applied and troweled, or hand applied. Floor slabs may require a higher thickness

Thicker Repairs – over 12 mm (1/2”) – Fibre-Patch OV

Suitable for horizontal, vertical and overhead application. For larger volumes consider using Spray-Con WS ST – wet shotcrete process applied mortar.

Curing

Applied materials can be exposed to water, once the final set takes place – allowing application between tides.

Advantages of Properly Formulated Systems

  • Permit applications under high temperatures & windy conditions
  • Low drying shrinkage
  • Resistance to cracking
  • Excellent adhesion
  • Excellent workability

Continuous Corrosion Protection – Gem-Gard MCI

Migrating corrosion inhibitor is applied the concrete surface to assure continuous protection of corroding reinforcing steel, especially in concrete with high content of de-icing salts.

Substructure – Concrete Protection

Waterproofing protection of marine concrete substructures.

If tide rise is not issue – Cem-Kote Flex ST

It must be let air dry cure for 3 days, before water exposure.

If tide rise must be considered – Cem-Kote CW Plus

It can be exposed to water only several hours after application

Protection of Surfaces above Water Level

Tuff-Flex CA provides flexibility and colour for surfaces above water – allow 12 hours air-dry cure before being exposure to water.

Substructure – Steel Protection

Steel piles and steel sheet piles are vulnerable to corrosion damage due to chloride (salt) attack, which may compromise its structural integrity. Use of remedial systems, providing that applied before the steel section loss, affords a long-term extension of useful life of these structures.

Fibre-Prime, rustproofing coating containing migrating corrosion inhibitor is the best solution for these areas,

Application Procedure – Fibre-Prime

  1. Use wet or dry abrasive sand blasting, or wire brush, to remove all loose rust, dust and other contaminants that could affect adhesion.
  2. “White metal”surface is not required
  3. Apply a thin coat of Fibre-Prime by spraying, or brushing and allow to dry for 10-15 minutes
  4. Apply second coat of Fibre-Prime to build a total min. dry film thickness of 1 mm (40 mils)
  5. 2-coat application assure that no pinholes are formed + provides a continuous protective membrane

Advantages of Fibre-Prime

  • Rustproofing can be applied to Damp steel surfaces
  • Rustproofing can be applied at High Relative Humidity
  • Does not require cleaning to white metal
  • Easy application
  • Fast set = Early resistance to water exposure

Wharf, Piers & Slabs – Traffic Coatings & Toppings

Surface Preparation

Surface must be prepared using shot blast or scarifying, depending on degree of deterioration and contamination, to obtain minimum CSP #3 per ICRI (International Concrete Repair Institute), followed by a high-pressure water to remove any dust or contamination.

Corrosion Protection – Fibre-Prime

Clean reinforcing steel using mechanical abrasion – “white metal” surface is NOT required.

Polymer modified cementitious rustproofing, with migrating corrosion technology, is applied in 2 coats over exposed rebar surface to protect partially “buried” steel, to provide protection from future rusting.

Cem-Kote Barrier Cote 100 – 3-6 mm (1/8”-1/4”)

Super durable, abrasion & impact resistant, polymerized cementitious heavy-duty traffic coating suitable for restoration and protection of airport traffic surfaces. It is spray or brush applied in 2-coats – can be opened to traffic after 24-hours of air-drying.

Gem-Crete HF ST –6-12 mm (1/4”-1/2”)

Thicker traffic bearing overlay that has an exceptional fracture toughness and crack resistance, combined with superior abrasion resistance. Highly flowable – easily applied by screeding – tining finish provides superior traction. Under normal conditions it can be open to traffic after 48 hours of air-drying.

Gem-Crete HDO –12-60 mm (1/2”-2”)

Heavy-Duty, highly fibre-reinforced traffic bearing bonded overlay is super tough and delivers excellent impact and abrasion resistance – over 25-years successful track record under high-traffic loads on highway bridge decks.

Cem-Kote Barrier Coat 100 must be used as bonding agent.

Advantages of Thin Traffic Bearing Bonded Toppings

  • Thin Application – less costly than partial slab replacement
  • Systems available for any Thicknesses
  • Easy & Fast Application – with Standard equipment & tools
  • High Abrasion & Impact resistance
  • UV stability
  • Easy maintenance

Adi-Con CSF (R) – toppings over 60 mm (2”)

Microsilica based admixture increases compressive strength up to 30% improves the chemical resistance of concrete and greatly improves concrete resistance to chloride penetration.

Advantages of Gemite’s Traffic Resurfacing

  • Thin section application
  • Low weight – Structural re-classification is NOT required
  • Easy and fast application
  • High abrasion and impact resistance

Continuous Corrosion Protection – Gem-Gard MCI

Migrating corrosion inhibitor is applied the concrete surface to assure continuous protection of corroding reinforcing steel, especially in concrete with high content of de-icing salts.