Renderoc HB Renderoc HB - Arcon Supplies

1 Renderoc HBRenderoc HB CI/SfB: (4-) Pr4 September 2003 Single component lightweight fibre andpolymer modified concrete reinstatementmortar for high-build applicationsUsesFor the reinstatement of large areas of concrete and forsmall, localised patch repairs. Renderoc HB is alkaline innature and will protect embedded steel reinforcement. It isspecifically designed for vertical and overhead high-buildapplications. The mortar is suitable where exceptionalchloride and carbon dioxide resistance is mortar is approved for use with Norcure to the Norcure note in the Application instructions section of this data sheet for formulation enabling extra high-build andthereby saving time and expense of multiple applicationsnReduces the need for formworknCan be applied by the wet spray process for fast,exceptionally high-build repairs with enhanced strengthnExtremely low permeability provides maximumprotection against carbon dioxide and chloridesnExcellent bond to the concrete substratenShrinkage compensatednPre-bagged to overcome site-batched variations onlythe site addition of clean water requirednContains no chloride admixturesnRenderoc Galvashield XP compatibleStandards complianceRenderoc HB, Nitoprime Zincrich, Nitobond HAR andNitobond AR have been approved by the British Board ofAgr ment, Certificate No.

2 98 HB is supplied as a ready to use blend of drypowders which requires only the site addition of clean waterto produce a highly consistent, lightweight repair material is based on Portland cement, gradedaggregates, lightweight fillers and chemical additives and ispolymer and fibre modified to provide a mortar with goodhandling characteristics, while minimising water hardened product exhibits excellent thermalcompatibility with concrete and outstanding water repellentproperties. The low water requirement ensures fast strengthgain and long-term supportFosroc offers a comprehensive range of high performance,high quality construction products. In addition, Fosrocoffers a technical support service to specifiers, end-usersand contractors, as well as on-site technical assistance inlocations all over the criteriaRenderoc HB can be applied in sections up to 80 mmthickness in vertical locations and up to 50 mm thickness inoverhead locations in a single application and without theuse of formwork.

3 Thicker sections can be achieved by theuse of formwork or can be built up in layers. Deep pocketscan sometimes be filled in a single application depending onthe actual configuration of the pocket and the volume ofexposed reinforcing steel. The material should not beapplied at less than 10 mm thickness. Thicknesses generallygreater than specified above can be achieved by sprayapplication. Consult the local Fosroc office for following results were obtained at a water:powder ratioof and temperature of 20 methodTypical resultCompressive strength(BS 6319, Pt 2: 1983 dry cure):7 N/mm @ 1 day12 N/mm @ 3 days16 N/mm @ 7 days22 N/mm @ 28 daysFlexural strength(BS 6319, Pt 3: 1983) N/mm @ 28 daysTensile strength(BS 6319, Pt 7: 1985) N/mm @ 28 daysWater absorption ISAT(BS 1881, Pt 5: 1970) 10 ml/m /sec2 ml/m /secFM 6102 Renderoc HBCI/SfB: (4-) Pr4 September 200342 Chloride diffusion(Taywood Method):< 2 x 10 10 cm /secCarbon dioxide barrier Equivalent thickness of concreteto Renderoc HB @ 10 mm(Taywood Method):800 mmEquivalent thickness of air toRenderoc HB @ 10 mm(Taywood Method):320 metresCoefficient of thermal expansion:7 to 12 x 10 6/ CSetting time(BS 4551, Pt 14: 1980) Initial set:2 hoursFinal set:5 hoursFire rating (BS 476, Pt 4: 1970).

4 Non-combustible(Class 0 surface)Fresh wet density:Approximately1400 kg/m dependent on actualconsistency usedChemical resistance:The low permeabilityof Renderoc HBseverely retardschemical attack inaggressiveenvironments. Thecured mortar is highlyimpermeable to acidgases, chloride ions,oxygen and waterSpecification clausesSteel reinforcement primerThe steel reinforcement primer shall be Nitoprime Zincrich, asingle component zinc-rich epoxy resin. The primer shall bean active type, capable of avoiding the generation ofincipient anodes in the immediately adjacent locations. Itshall be fully compatible with the Renderoc system ofconcrete mortarThe fibre and polymer modified reinstatement mortar shallbe Renderoc HB, a single component cement-based blendof powders to which only the site-addition of clean watershall be permitted. The cured mortar shall achieve acompressive strength of 22 N/mm , a flexural strength N/mm and a tensile strength of N/mm at 28 diffusion coefficient shall be not greater than2 x 10 10 cm /sec (by the Taywood Method) and a 10 mmsection of cured mortar shall provide a carbon dioxidebarrier equivalent to not less than 800 mm concrete or320 metres air (by the Taywood Method).

5 Application instructionsPreparationSaw cut or cut back the extremities of the repair locations toa depth of at least 10 mm to avoid feather-edging and toprovide a square edge. Break out the complete repair area toa minimum depth of 10 mm up to the sawn the surface and remove any dust, unsound orcontaminated material, plaster, oil, paint, grease, corrosiondeposits or algae. Where breaking out is not required,roughen the surface and remove any laitance by lightscabbling or and grease deposits should be removed by steamcleaning, detergent scrubbing or the use of a proprietarydegreaser. The effectiveness of decontamination shouldthen be assessed by a pull-off fully any corroded steel in the repair area andremove all loose scale and corrosion deposits. Steel shouldbe cleaned to a bright condition paying particular attentionto the back of exposed steel bars. Grit-blasting isrecommended for this corrosion has occurred due to the presence ofchlorides, the steel should be high-pressure washed withclean water immediately after grit-blasting to removecorrosion products from pits and imperfections within steel primingApply one full coat of Nitoprime Zincrich and allow to drybefore continuing.

6 If any doubt exists about havingachieved an unbroken coating, a second application shouldbe made and, again, allowed to dry before primingThe substrate should be saturated surface dry immediatelybefore the application of the primer it should bethoroughly saturated with clean water and any residualsurface water removed prior to applying one coat ofNitobond HAR primer and scrubbing it well into the severe drying conditions repeated soaking may benecessary to ensure the substrate is still saturated at thetime of application of the primer. Renderoc HB can beapplied as soon as the primer becomes tacky. If theNitobond HAR is too wet, overhead and vertical build up ofthe Renderoc HB mortar may be HBCI/SfB: (4-) Pr4 September 200343In exceptional circumstances, where a substrate/repairbarrier is required or where the substrate is wet or likely toremain permanently damp, Nitobond EP bonding aid shouldbe used. Contact the local Fosroc office for should be taken to ensure that Renderoc HB isthoroughly mixed.

7 A forced-action mixer is essential. Mixingin a suitably sized drum using an approved spiral paddle in aslow speed (400/500 rpm) heavy-duty drill is acceptable forthe occasional one-bag mix. Free-fall mixers must not beused. Mixing of part bags should never be normal applications, place litres of drinking qualitywater into the mixer and, with the machine in operation, addone full 18 kg bag of Renderoc HB and mix for a minimumof 3 minutes (maximum 5 minutes). Note that powder mustalways be added to water. Dependent on the ambienttemperature and the desired consistency, a small additionalamount of water may be added up to a maximumtotal water content of litres per 18 kg bag of Renderoc warningAs with other one pack repair mortars, Renderoc HB mayexhibit satisfactory handling characteristics even thoughinadequately mixed. This will result in a significantly lowerlevel of performance or possible failure. It is thereforeessential that mixing instructions are strictly adhered to withparticular emphasis on the quantity of water used and thetime of the mixing steel reinforcing bars should be firmly secured toavoid movement during the application process as this willaffect mortar compaction, build and the mixed Renderoc HB to the prepared substrate bygloved hand or trowel.

8 First, work a thin layer of the mortarinto the primer and then build the mortar on to this compact the mortar on to the primed substrateand around the exposed reinforcement. Renderoc HB can beapplied in sections up to 80 mm thickness in verticallocations and up to 50 mm thickness in overhead locationsin a single application and without the use of sections should be built up in layers but aresometimes possible in a single application depending onthe actual configuration of the repair area and the volume ofexposed reinforcing sagging occurs during application, the Renderoc HBshould be completely removed and reapplied at a reducedthickness on to the correctly reprimed : the minimum applied thickness of Renderoc HB is10 build-up can be achieved by application ofmultiple layers. The final thickness is dependent on thematerial consistency and substrate surface of the intermediate layers should be combscratch-keyed and cured with Nitobond AR.

9 Repriming withNitobond HAR and a further application of Renderoc HBmay proceed as soon as this layer has applicationRenderoc HB can be applied by the wet spray technique. Incircumstances where large areas of repair are required, therapid placement and higher build attainable by this methodoffer economic advantages over hand-trowelling. Theresultant repair also offers a generally more densecompound with greatly enhanced mortar/substrate bondcharacteristics. For further details on wet spray techniquesconsult the local Fosroc HB is finished by striking off with a straight edgeand closing with a steel float. Wooden or plastic floats, ordamp sponges may be used to achieve the desired surfacetexture. The completed surface should not be temperature workingIn cold conditions down to 5 C, the use of warm mixingwater (up to 30 C) is advisable to accelerate strengthdevelopment. Normal precautions for winter working withcementitious materials should then be adopted.

10 The materialshould not be applied when the substrate and/or airtemperature is 5 C and falling. At 5 C static temperature orat 5 C and rising, the application may temperature workingAt ambient temperatures above 35 C, the material should bestored in the shade and cool water used for HBCI/SfB: (4-) Pr4 September 200344 CuringRenderoc HB is a cement-based repair mortar. In commonwith all cementitious materials, Renderoc HB must be curedimmediately after finishing in accordance with goodconcrete practice. The use of Nitobond AR, sprayed on tothe surface of the finished Renderoc HB in a continuousfilm, is recommended. Large areas should be cured astrowelling progresses ( m at a time) without waiting forcompletion of the entire area. In fast drying conditions,supplementary curing with polythene sheeting taped downat the edges must be used. In cold conditions, the finishedrepair must be protected from note: When using this mortar in conjunction withNorcure realkalisation, polymer bonding primers andpolymer curing agents should not be used.