System SikaProof® A+

The patented unique Sikaproof^® A+ membrane system (polyolefin base - FPO) is Sika's most effective and  specialized solution for sealing reinforced concrete underground structures.

For the case of horizontal applications, It is loose laid onto prepared substrates or formwork before fixing reinforcement and casting concrete. It is common practice to apply a geotextile (at least 300 gr) before the membrane to smooth the substrate. All overlap and transverse joints must be bonded and sealed either with cold applied SikaProof^® Tape A+ or SikaProof^® Sandwich Tape. Alternatively joints can be thermal jointed with appropriate hot air heating equipment.

In the case of inclined substrate (basement walls), the membranes are temporarily fixed to the mold before the reinforcement is installed. After concreting, any external holes from the mold removal are sealed with the special Sikaproof^® Patch 200B tape and external surfaces are protected during earthworks with drainage membrane, geotextile, or polystyrene, etc.

The pre-applied  system is installed in the formwork before the reinforcement is placed, and the structural concrete is cast. The fresh concrete is cast onto the membrane and covers the surface of the hybrid bonding layer to form the dual bond. Available technical solutions/details regarding pile caps and expansion joints (pile caps).

ADVANTAGES

• Ideal for constructions with high aquifer
• No special equipment or specialized workshops are required for their installation
• No lateral water underflow or migration between the concrete structure and the membrane system
• Faster implementation of the system compared to the competition (it is estimated that two people can place 100 m² - 10 m x 10 m - in just 18 minutes)
• Use of coldapplied self-adhesive tapes for overlays/perforations (certified proof of waterproofing of the joints) without the need for heat sealing making the system less likely to fail than the joints
• Dual bond: Mechanical and adhesive bond with fresh concrete

Fully bonded system with compartmenship method which means that even in case of loss or damage, water does not circulate throughout the construction as in conventional membranes, but is limited to the point of failure and the repair is very easy and painless.

In contrast to the competition, Sikaproof^® A+ membranes offer very high protection and resistance against corrosive agents e.g. chemicals and seawater, characteristic of FPO membranes. Very high flexibility and with the possibility of bridging cracks of such a width that other materials/systems would fail.

The development of the system is as follows:

• Cleanliness concrete. Substrate quality control
• Laying of geotextile weighing at least 300 gr/m²
• Installing Sikaproof^® A+ Membrane (SikaProof^® A 08+ 0.8 mm thick or SikaProof^® A 12+ 1.2 mm thick)
• Sealing connetctions, details and corners with Sikaproof^® Tape A+ or Sikaproof^® Sandwich Tape
• Application control of membranes and details/connections
• Installation of reinforcement
• Final system check for any damage during previous work
• Concreting

In the case of walls, after mold removal and before embankments fill, protect the membrane with a suitable drainage membrane, polystyrene or geotextile.

In cases where it is not possible to apply the membrane before concreting, there is also a version of the membrane in self-adhesive (SikaProof^® P = Post-applied) which is applied with a special adhesive / primer to the ready-mixed concrete after the completion of concreting.