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32857 Parchem Technical Data Compendium 2015_Crop4emag.pdf

CONTENTS CONCRETE REPAIR CORROSION CONTROL GROUTS & ANCHORS PROTECTIVE COATINGS INDUSTRIAL FLOORING SURFACE TREATMENTS JOINT SEALANTS CONCRETE JOINTING ROOFING WATERSTOPS WATERPROOFING JOINT FILLERS TIMBER FLOORING ALPHABETICAL Application Instructions Preparation Saw cut or cut back the extremities of the repair locations to a depth of at least 10 mm to avoid feather-edging and to provide a square edge. Break out the complete repair area to a minimum depth of 10 mm up to the sawn edge. Clean the surface and remove any dust, unsound or contaminated material, plaster, oil, paint, grease, corrosion deposits or algae. Where breaking out is not required, roughen the surface and remove any laitance by light scabbling or grit-blasting. Oil and grease deposits should be removed by steam cleaning, detergent scrubbing or the use of a proprietary degreaser. The effectiveness of decontamination should then be assessed by a pull-off test. Expose fully any corroded steel in the repair area and remove all loose scale and corrosion deposits. Steel should be cleaned to a bright condition paying particular attention to the back of exposed steel bars. Grit-blasting is recommended for this process. Where corrosion has occurred due to the presence of chlorides, the steel should be high-pressure washed with clean water immediately after grit-blasting to remove corrosion products from pits and imperfections within its surface. Reinforcing steel priming Apply one full coat of Nitoprime Zincrich and allow to dry before continuing. If any doubt exists about having achieved an unbroken coating, a second application should be made and, again, allowed to dry before continuing. Application Exposed steel reinforcing bars should be firmly secured to avoid movement during the application process as this will affect mortar compaction, build and bond. The substrate should be thoroughly washed with clean water and any excess water removed prior to the spray application of the Guncrete E. Apply the Guncrete E to the prepared substrate using suitable guniting or shotcreting equipment. Ensure thorough compaction of the mortar around the exposed reinforcement. Guncrete E can be applied in sections from 10 mm up to 150 mm in one pass depending on substrate geometry. If sagging occurs during application to vertical surfaces, the Guncrete E should be completely removed and reapplied at a reduced thickness on to the substrate. Note: the minimum applied thickness of Guncrete E is 10 mm. Finishing Guncrete E is finished by striking off with a straight edge and closing with a steel float. Wooden or plastic floats, or damp INDEX 32 sponges may be used to achieve the desired surface texture. The completed surface should not be overworked. Guncrete E’s aggregate composition provides for a textured finish affect. If a smooth, closed render appearance is required, the subsequent application of Renderoc FC is necessary. Low temperature working In cold conditions the material should not be applied when the substrate and/or air temperature is 5°C and falling. At 5°C static temperature or at 5°C and rising, the application may proceed. High temperature working At ambient temperatures above 35°C, the material should not be used as this will cause premature setting. Curing Guncrete E is a cement-based repair mortar. In common with all cementitious materials, Guncrete E must be cured immediately after finishing in accordance with good concrete practice. The use of Nitobond AR, sprayed on to the surface of the finished Guncrete E in a continuous film, is recommended. Large areas should be cured as trowelling progresses (0.5 at a time) without waiting for completion of the entire area. In fast drying conditions, supplementary curing with polythene sheeting taped down at the edges must be used. In cold conditions, the finished repair must be protected from freezing. Overcoating with protective decorative finishes Guncrete E is extremely durable and will provide excellent protection to the embedded steel reinforcement within the repaired locations. The surrounding parts of the structure will generally benefit from the application of a protective barrier/ decorative coating to limit the advance of chlorides and carbon dioxide, thus bringing them up to the same protective standard as the repair itself. Parchem recommend the use of the Emer-Clad and Dekguard range of protective, anticarbonation coatings. These products provide a decorative and uniform appearance as well as protecting areas of the structure which might otherwise be at risk from the environment. Where appropriate, Emer-Clad and Dekguard products may be applied over the repair area without prior removal of the Nitobond AR curing membrane. Other curing membranes must be removed prior to the application of Emer-Clad or Dekguard products. Cleaning Nitobond AR and Guncrete E should be removed from tools, equipment and mixers with clean water immediately after use. Cured material can only be removed mechanically. Equipment used with Nitoprime Zincrich should be cleaned with Solvent 10. Fosroc® Guncrete E


32857 Parchem Technical Data Compendium 2015_Crop4emag.pdf
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