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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 Fosroc® Nitobond SBR 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 1 full coat of Nitoprime Zincrich to any exposed steel reinforcement 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. Substrate priming The substrate should be thoroughly soaked with clean water and any excess removed prior to commencement. A slurry primer should be prepared consisting of 1 volume Nitobond SBR to 1 volume clean water to 3 volumes fresh cement. To obtain a smooth consistency, the cement should be blended slowly into the premixed liquids. The slurry primer should be stirred frequently during use to offset settlement. The slurry primer should be scrubbed well into the surface of the concrete. Avoid applying too thickly and avoid ‘puddling’. The repair mortar, topping or render must be applied on to the wet slurry primer. If the slurry primer dries before application of the mortar, it must be removed and the area reprimed before continuing. In exceptional circumstances, e.g. where a substrate/repair barrier is required or where the substrate is likely to remain permanently damp, Nitobond EP bonding aid should be used. Contact your local Parchem branch for further information. Mixing Care should be taken to ensure that Nitobond SBR mortars are thoroughly mixed. A forced-action mixer is essential. Mixing in a suitably sized drum using an approved spiral paddle in a slow speed (400/500 rpm) heavy-duty drill is acceptable for occasional use. A wide range of mix designs is achievable using Nitobond SBR. Typical designs are detailed below: 1. Patching and repair mortar: INDEX 76 50 kgs Ordinary Portland Cement 150 kgs grade C/M sharp sand 10 litres Nitobond SBR 8 litres (approximately) clean water Recommended thickness: 6 mm - 40 mm 2. Heavy-duty floor screed: 50 kgs Ordinary Portland Cement 75 kgs 3 to 6 mm granite chips 75 kgs grade C/M sharp sand 10 litres Nitobond SBR 6 litres (approximately) clean water The screed should be of a semi-dry cohesive consistency. Recommended thickness: 10 mm - 40 mm 3. Render: 50 kgs Ordinary Portland Cement 150 kgs grade C/M sharp sand 10 litres Nitobond SBR 6 litres (approximately) clean water The render should be of a semi-dry cohesive consistency. Recommended thickness: 6 mm - 9 mm 4. Bonding mortar for slip bricks, tiles, etc: 50 kgs Ordinary Portland Cement 125 kgs grade C/M sharp sand 10 litres Nitobond SBR 7 litres (approximately) clean water Water is adjusted to give a firm mortar. For fine joints, use grade M/B sand. Support where necessary until the mortar is set. Recommended thickness: 6 mm to 40 mm. Note: these mix designs are based on the use of dry sand and aggregate. Adjustments must be made to the water demand relative to the moisture content of the sand and aggregate used. It should also be noted that, due to the frequent inconsistencies of site-stored materials and variable conditions, actual results may differ from those published above. Weigh the cement, sand and, where required, aggregate into the mixer and dry blend together for 1 minute. With the machine in operation, add the pre-mixed Nitobond SBR and clean water. Continue mixing for 3 minutes to ensure complete dispersal into the sand and cement. Make any small adjustment to the quantity of clean water but do not significantly exceed the litreage shown above. Additional water should be kept to a minimum. Continue mixing up to a maximum of 5 minutes until a smooth and fully homogeneous consistency is achieved with the required workability and application properties. It is critical that allowance is made for the moisture content of the sand and aggregate, particularly where they are stored on site. Application For application to all surfaces, Nitobond SBR mortars, toppings and renders must be well-compacted on to the primed substrate by trowel. It is frequently beneficial to work a thin layer of the mortar into the slurry primer and then build the mortar on to this layer. Exposed steel reinforcement should be completely encapsulated by the mortar. Nitobond SBR mortars can be applied at a minimum thickness of 6 mm and up to 40 mm thickness, dependent on the location and configuration of the repair zone. The thickness achievable in overhead locations without the use of formwork is largely dependent on the profile of the substrate. Refer to the recommended thicknesses shown in the ‘Mix design’ section above. If the recommended thickness is exceeded and sagging occurs, the affected section must be completely removed and reapplied in accordance with the procedure described above. The use of formwork may facilitate achieving the required build. If formwork is used, it should have properly sealed faces to ensure that no water is absorbed from the repair material.


32857 Parchem Technical Data Compendium 2015_Crop4emag.pdf
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