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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 JOINT FILLERS WATERPROOFING WATERSTOPS ROOFING TIMBER FLOORING ALPHABETICAL INDEX 7 be used. Contact your local Parchem sales office for further information. Note: Nitobond HAR primer is generally not required when wet spraying Renderoc HB40. Refer to the separate information document “Wet Spraying Renderoc mortars” available from Parchem branches. Mixing Care should be taken to ensure that Renderoc HB is thoroughly mixed. A forced-action mixer is essential. Mixing in a suitably sized drum using an appropriate spiral paddle such the Protool HS2 140 x 600 M14 Helical mixing paddle (product code: TT-614217) or equivalent at a slow speed (400/500 rpm) using a heavy-duty mixer, 1500W such as Protool MXP 1602 E (product code: TT-621941) or equivalent is acceptable for the occasional one-bag mix. Free-fall mixers must not be used. Mixing of part bags should never be attempted. For normal applications, place 2.6 litres of drinking quality water into the mixer and, with the machine in operation, add one full 15 kg bag of Renderoc HB and mix for 3 to 5 minutes until fully homogeneous. Dependent on the ambient temperature and the desired consistency, a small additional amount of water may be added up to a maximum total water content of 2.7 litres per 15 kg bag of Renderoe HB. Note: In all cases Renderoc HB powder must be added to water. 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. Apply the mixed Renderoc HB to the prepared substrate by gloved hand or trowel. First, work a thin layer of the mortar into the primer and then build the mortar on to this layer. Thoroughly compact the mortar on to the primed substrate and around the exposed reinforcement. Renderoc HB can be applied in sections up to 80 mm thickness in vertical locations and up to 50 mm thickness in overhead locations in a single application and without the use of formwork. Thicker sections should be built up in layers but are sometimes possible in a single application depending on the actual configuration of the repair area and the volume of exposed reinforcing steel. If sagging occurs during application, the Renderoc HB should be completely removed and reapplied at a reduced thickness on to the correctly reprimed substrate. Note: the minimum applied thickness of Renderoc HB is 10 mm. Build-up Additional build-up can be achieved by application of multiple layers. The final thickness is dependent on the material consistency and substrate profile. The surface of the intermediate layers should be scratch- keyed and cured with Nitobond AR. Repriming with Nitobond HAR and a further application of Renderoc HB may proceed as soon as this layer has set. Spray application Renderoc HB can be quickly and efficiently applied by the wet spray technique. In circumstances where large areas of repair are required, the rapid placement and higher build attainable by this method offer economic advantages over hand-trowelling. The resultant repair also offers a generally more dense compound with enhanced mortar/substrate bond characteristics. For further details on the wet spray technique, including selection of spraying machines and nozzles, consult the document “Wet Spraying Renderoc mortars” or contact your local Parchem sales office. Finishing Renderoc HB is finished by striking off with a straight edge and closing with a steel trowel. Wooden or plastic floats, or damp sponges may be used to achieve desired surface texture. The completed surface should not be overworked. Allow the applied Renderoc to stiffen before attempting to finish off - this will minimise slumping. After spray application, the mortar may need to be ‘cut back’ to the required profile using a steel trowel and then finished with damp sponges as described above. Low temperature working In cold conditions down to 5°C, the use of warm water (up to 30°C) is advisable to accelerate strength development. Normal precautions for winter working with cementitious materials should then be adopted. The material should not be applied when the substrate and/or air temperature is 5°C and failing. 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 be stored in the shade and cool water used for mixing. Curing Renderoc HB is a cement-based repair mortar. In common with all cementitious materials, Renderoe HB must be cured immediately after finishing in accordance with good concrete practice. The use of Nitobond AR or Concure A99, sprayed on to the surface of the finished Renderoc 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 Renderoc HB is extremely durable and will provide excellent protection to the embedded steel reinforcement within the Fosroc® Renderoc HB


32857 Parchem Technical Data Compendium 2015_Crop4emag.pdf
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