SpECbuild SG15

SpECbuild SG15 is designed to provide a structural grade repair mortar particularly in situations where abrasion resistance and low permeability are required, such as:
· Repairs to structural concrete elements, e.g. reinforced beams and columns
· Highly trafficked surfaces, particularly transition strips adjacent to mechanical bridge joints
· Repairs in marine environments or other situations where concrete is in contact with chloride or sulphate solutions

· High bond strength to concrete substances.
· Good abrasion resistance.
· High compressive strength.
· Coefficient of thermal expansion similar to host concrete.
· Compensated for plastic and long-term shrinkage
· Low permeability providing protection against the ingress of chlorides and carbon dioxide

Preparation
It is essential that adequate preparation is carried out prior to the application of SpECbuild SG15. This preparation should ensure the removal of all grease, oil and loose material.

The area to be reinstated using SpECbuild SG15 should be cut back to a depth of at least 10mm. To avoid “feather edging”, it is advisable to neatly delineate the repair boundary by saw cutting to a depth of 10mm.

All corroded steel should be completely exposed including the rear of the bar to enable thorough cleaning. It is recommended that grit blasting be used to clean the reinforcing steel and particular attention should be paid to the rear of the bar to ensure all corrosion products have been removed. Once the reinforcing steel has been cleaned it should be coated immediately with one coat of SpECcoat Zn25.

Substrate Priming For most situations, the substrate should be primed with SpECbuild Primer S1. Initially the surface should be thoroughly saturated without standing water prior to the primer being applied by brush, ensuring intimate contact with the substrate. This is best achieved by using a circular scrubbing action. SpECbuild SG15 can be applied as soon as the primer becomes tacky.

To provide an exceptionally high strength, sealed bond to the substrate (e.g. to repair chloride induced corrosion damage), SpECbuild Primer E1 epoxy resin bonding agent may be used. One coat should be applied and allowed to gel. A second coat should then be applied and used to provide the bond.

Where SpECbuild SG15 is applied by spray, then sharp sand may be broadcast into the surface of the second coat of SpECbuild Primer E1 and be allowed to dry.

Mixing
SpECbuild SG15 is a one-part cementitious repair compound.
For mixing a single bag, a 25 litre steel pail is suitable, using a slow speed electric drill (350/600rpm) fitted with a SpECbuild Mixing Paddle. Where larger quantities of material need to be mixed at one time a compulsory mixer is required. Do not attempt to use free-fall mortar mixers as they do not impart sufficient shear to adequately mix the repair compound.

Place 2.25 to 2.75 litres of clean water in the mixing vessel and slowly add the contents of the bag with the mixer running. The product should be mixed for a minimum of 5 minutes. Do not attempt to use the product if it has not been mixed for the minimum time, as a loss in the performance of the product is likely which could result in failure of the repair.

This product cannot be mixed by hand. Application
The material should be applied by a gloved hand to ensure thorough compaction around the reinforcement and against the edges of the reinstatement area. The repair is then trowel finished.
The product can be applied up to 15mm in thickness in vertical, unsupported situations and up to 40mm in recessed, supported repairs. The product can be applied in 100mm layers in the horizontal plane. The material should not be applied at less than 10mm thick.

Curing
SpECbuild SG15 should be cured using a SpECcure WE. In extreme drying conditions a second coat should be applied immediately the first coat has dried.