Page 32

Technical Dayta Sheet Compedium

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 minimum depth of at least 5 mm to avoid feather-edging and to provide a square edge. Break out the repair area to a minimum depth of 5 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. (If Galvashield XP are to be embedded into the Renderoc HB70 patch repair, refer to the current Galvashield XP Technical Data Sheet for priming instructions). Substrate priming The substrate should be thoroughly soaked with clean water and any excess removed prior to applying one coat of Nitobond HAR primer and scrubbing it well into the surface. Renderoc HB70 can be applied as soon as the primer becomes tacky. If the Nitobond HAR is too wet, overhead and vertical build up of the Renderoc HB70 mortar may be difficult. Scrubbing by hand a thin layer of the Renderoc into the tacky primer will assist adhesion and also minimise the chance of the primer drying out. If the Nitobond HAR primer dries before the application of the Renderoc, the area must be re-primed before proceeding. In exceptional circumstances, e.g. where a substrate/repair barrier is required or where the substrate is wet or likely to remain permanently damp, Nitobond EP bonding aid should be used. Contact your local Parchem sales office for further information. Note: Nitobond HAR primer is generally not required when wet spraying Renderoc HB70. Refer to the separate information document “Wet Spraying Renderoc mortars” available from Parchem branches. Mixing Care should be taken to ensure that Renderoc HB70 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 2.8 - 3.0 litres of drinking quality water into the mixer and, with the machine in operation, add 1 full 20 kg bag of Renderoc HB70 and mix for 3 - 5 minutes until fully homogeneous. Note that powder must always be added to water. Dependent on the ambient temperature and the desired consistency, the amount of water required may vary slightly but should not exceed 3.0 litres / 20 kg bag of Renderoc HB70. 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 HB70 to the prepared substrate by gloved hand or trowel. Thoroughly compact the mortar on to the primed substrate and around the exposed reinforcement. Renderoc HB70 can be applied up to 40 mm thickness in vertical sections but greater thickness in smaller pockets or with the use of formwork. If formwork is used, it should have properly sealed faces to ensure that no water is absorbed from the repair material. In horizontal locations, Renderoc HB70 can be applied up to 150 mm thickness. If sagging occurs during application to vertical surfaces, the Renderoc HB70 should be completely removed and reapplied at a reduced thickness on to the correctly reprimed substrate. Note: the minimum applied thickness of Renderoc HB70 is 5 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 scratchkeyed INDEX 20 Page 3 and cured with Nitobond AR. Repriming with Nitobond HAR and a further application of Renderoc HB70 may proceed as soon as this layer has set. Fosroc® Renderoc HB70


Technical Dayta Sheet Compedium
To see the actual publication please follow the link above