Poor concrete finishing techniques, rained-on and frozen concrete, combined with heavy traffic and snow contribute to erosion and surface roughness on surfaces of foundation slabs (on-grade). Surface roughness represents a serious liability problem due to trips and falls.
Additionally, these slabs suffer from drying shrinkage cracking, delamination due to corrosion of the reinforcing steel, water leaks, and failing expansion joints.
Non-breathable epoxy or polyurethane membranes are NOT suitable – they de-bond due to water vapor transfer causing condensation at the concrete membrane interface and buildup of capillary pressures.
Gemite offers a unique system for thin section repairs and waterproofing of parking garage slabs.
Traffic Membranes – Restoration and Waterproofing
Clean the reprofiled surface using 48 MPa (7,000 psi) pressure water, shotblasting or scarifying must be used 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.
Cracks & Delaminations
All existing cracks, spalls and delaminations must be repaired before proceeding with membrane application, as follows:
Cracks Cem-Kote Flex ST & Reinforcing Fabric HD
Delaminations Fibre-Patch OV & Cem-Kote Barrier Cote 100 as a bonding agent
Gem-Crete HF ST –6-12 mm (1/4”-1/2”)
Apply using a squeegee and finishing broom to even out the deteriorated rough and smooth surfaces. It has an exceptional fracture toughness and crack resistance, combined with superior abrasion resistance. Highly flowable – easily applied.
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 traffic surfaces. It is spray applied and finished using a broom. It can be opened to traffic after 24-hours of air-drying.
- Thin System – NO reduction of head space, or need for structural reinforcements
- Superior abrasion
- Extremely high impact resistance
- Easy & Simple application
- Non-toxic, NO VOC, No Odor
- Breathable – but allows application of non-breathable polymer coating (if required)
- Much cheaper & Faster than slab replacement
Gem-Coat WA Plus
If a colored surface is required, pressure wash the surface using 34 MPa (5,000 psi) pressure water, let dry overnight, and apply two coats of Gem-Coat WA Plus, waterborne, high abrasion resistant color, traffic coating.
Advantage of Gem-Coat WA Plus
- High breathability
- NO Odor
- Easy application in closed environments
- Zero or low VOC
Migrating corrosion inhibitor, which may be surface applied in restoration projects to provide a further protection of corroding reinforcing steel, especially in concrete with high content of de-icing salts.
Negative Side Waterproofing
Underground parking structures often suffer from outside water penetration, typically through cracks, joints, but also through areas of poorly compacted concrete or failing water seals at slab wall junctions.
Gemite offers several products that can be used to provide the negative side waterproofing, even under very high-water levels, or below rivers.
The active leaks need to be sealed first for a minimum three days. This is achieved using hydraulic fast setting cement, Fibre-Patch WP (water plug) or polyurethane injection. After surface preparation, typically 5,000 psi pressure water, Cem-Kote Flex ST or Cem-Kote CW Plus (crystalline water proofing) is used to provide negative side waterproofing. The cracks are treated with a strip of Reinforcing Fabric HD and Cem-Kote Flex ST. Cem-Kote Flex ST is air cured, Cem-Kote CW Plus needs to be moist cured for a minimum of three days.
Sealers provide protection against water and salt penetration for an extended period. It is recommended to re-apply them in 5-7 years.
Gem-Gard SL (VOC)
The small molecular size of silane penetrating sealer allows maximum penetration into the concrete substrate and delivers permanent protection against water and chloride ions. The solvent borne formulation is VOC compliant.
Gem-Gard SL ST WB
Molecular size water borne penetrating sealer preventing water & chloride intrusion into concrete with an excellent performance on horizontal traffic surfaces. The active molecular material reacts chemically with cement when moisture is present and delivers permanent long-term protection. Gem-Gard SL ST WB is breathable, allowing moisture to escape freely.
Gem-Seal WA Plus
Highly penetrating, Nano-polymer water borne sealer provides superior protection for concrete against water and oil penetration and staining. It provides high impact and abrasion resistance and a very good cleanability.