CONBEXTRA HF

Conbextra HF is suitable for use in contact with potable water. Conbextra HF meets or exceeds the test requirements of ASTM C 1107.

Fosroc offers a comprehensive technical support service to specifiers, end users and contractors. It is also able to offer on-site technical assistance, an AutoCAD facility and dedi- cated specification assistance in locations all over the world. Dual expansion system for shrinkage compensated, highly fluid cementitious precision grout Figure 1 : Typical specification drawing Conbextra HF- Page 2 of 4 Fosroc Conbextra HF

Conbextra HF should be removed from tools and equipment with clean water immediately after use. Cured material can be removed mechanically, or with Fosroc Acid Etch* † . UAE/0329/16/J Fosroc Conbextra HF Al Gurg Fosroc LLC Post Box 657, Dubai United Arab Emirates www.fosroc.com

• Fosroc products are guaranteed against defective materials and manufacture and are sold subject to its standard Conditions for the Supply of
• Goods and Service. All Fosroc datasheets are updated on a regular basis. It is the user’s responsibility to obtain the latest version.
• Head Office
• telephone: (+9714) 2039699 fax: (+9714) 2859649 email: agf@fosroc.com
• Regional offices
• Abu Dhabi, Al Gurg Fosroc telephone: 673 1779 fax: 673 1449 email: abudhabi@fosroc.com
• Bahrain, YBA Kanoo telephone: 17738200 fax: 17732828 email: bahrain@fosroc.com
• Kuwait, Boodai telephone: 4817618 fax: 4832124 email: kuwait@fosroc.com
• Oman, Al Amana telephone: 24815080 fax: 24817554 email: oman@fosroc.com
• Denotes the trademark of Fosroc International Limited
• †
• See separate data sheet
• Sampling procedure
• Cementitious grouts cannot be tested as concrete. Special
• sampling procedure are required. Refer to your local Fosroc
• office for further details.
• High temperature working
• It is suggested that, for temperatures above 35°C, the
• following guidelines are adopted as good working practice:
• (i) Store unmixed material in a cool (preferably temperature
• controlled) environment, avoiding exposure to direct
• sunlight.
• (ii) Keep equipment cool, arranging shade protection if
• necessary. It is especially important to keep cool those
• surfaces of the equipment which will come into direct
• contact with the material itself.
• (iii) Try to eliminate application during the hottest times of the
• day and in direct sunlight.
• (iv) Make sufficient material, plant and labour available to
• ensure that application is a continuous process.
• (v) Water (below 20°C) should be used for mixing the grout
• prior to placement

• In general, grouts should not be placed in any unre-
• strained situation, i.e. base plate plinths, etc. Failure to
• comply may lead to crack development in the grout.
• However they can be used for bolt pockets. In doubt,
• please consult your local Fosroc offices for more details.
• Estimating

Conbextra HF has a shelf life of 12 months if kept in a dry store in sealed bags. If stored in high temperature and high humidity locations the shelf life will be reduced.

Conbextra HF is alkaline and should not come into contact with skin and eyes. Avoid inhalation of dust during mixing. Gloves, goggles and dust mask should be worn. If contact with skin occurs, wash with water. Splashes to eyes should be washed immediately with plenty of clean water and medical advice sought. Fire Conbextra HF is non-flammable.

• It is suggested that the following list of equipment is adopted as a minimum requirement :
• Protective clothing : Protective overalls
• : Good quality gloves, goggles and face mask
• Preparation equipment : Electric or pneumatic breaker
• : Hammer and chisel
• Mixing equipment : Measuring jug
• : 1 KW slow speed drill, 400 or 500 rpm, plus
• Fosroc mixing paddle and mixing vessel, or
• : Forced-action mixer, fitted with a suitable paddle
• Application equipment : Formwork
• : Pouring equipment
• Page 2 of 5
• constructive solutions
• Application - points of note
• Fosroc operates a policy to encourage the use, where possible, of approved or licensed applicators.
• This ensures that works are completed satisfactorily so that the long term performance of the
• materials is assured. For contractors who wish to apply the materials themselves Fosroc is also able
• to offer technical assistance and training, either on-site or at its Training Centre in Dubai.
• B: Application Method
• Surface Preparation
• Attention to full and proper preparation is essential to successful grouting.
• The substrate surface must be free from oil, grease or any loosely adherent material.
• Remove laitance, defective surfaces must be cut back to a sound base.
• Blow clean all bolt holes or fixing pockets of any dirt or debris.
• Bearing plate/base plate
• The underside of the base plate should be clean and free from oil, grease, rust, scale or other
• loosely adherent material.
• It may be necessary to provide air pressure relief holes to allow venting of any isolated high
• spots.
• If levelling shims are to be removed once the grout has hardened, then they should be pre-
• treated with a thin layer of grease.
• Formwork - general
• Before fixing any formwork, ensure that the area to be grouted is clean.
• The formwork itself must be constructed to be leak proof, to prevent any possible grout loss.
• This can be achieved by using foam rubber strip or mastic sealant beneath the formwork, and
• at any joints in the formwork. It shall, however, also be provided with drain holes and plugs.
• The formwork should also be constructed in such a way as to keep the final, unrestrained
• surface area of the grout to a minimum, to avoid problems with cracking at a later stage.
• Page 3 of 5
• constructive solutions
• It should be fixed in such a way as to allow easy stripping, without causing damage or
• distress to the grout - particularly if this is to be done whilst the grout is still „green‟.
• All dirt and debris to be removed from the grout area before the last piece of formwork is
• fixed, to facilitate pre-soaking (see below).
• Formwork - geometry
• Pouring side
• set up so that grout will be poured the shortest distance across the base plate
• erected a maximum of 75 mm from the base plate edge
• erected a minimum of 150 mm higher than the underside of the base plate
• Open side
• set up directly opposite the pouring side
• erected a maximum of 25 mm from the plate edge
• erected a minimum of 25 mm from the underside of the plate
• Flanking sides
• set up flush with the plate edge
• close attention to „grout tightness‟ of the formwork.
• Page 4 of 5
• constructive solutions
• Pre-soaking
• All concrete surfaces within the formwork area should be saturated with clean, fresh water for
• several hours prior to grouting.
• Immediately before grouting takes place, any free water should be removed. Particular care
• should be taken to blow out all bolt holes and pockets.
• Mixing
• For best results a mechanically powered grout mixer should be used - do not use a colloidal
• impeller mixer.
• For small quantities of grout a slow speed drill (400/500 rpm) fitted with a high shear paddle
• is acceptable, but mixing should be restricted to one bag at a time in a container of minimum
• capacity 25 litres.
• Measure out clean water into the mixer, as per below mentioned quantities:
• litres for flowable consistency of the mix / 25kg bag
• litres for fluid consistency of the mix / 25kg bag
• Slowly add the full bag of Conbextra HF to the water and mix continuously for 5 minutes, until
• a smooth, free flowing consistency is obtained.
• Under no circumstances should part bags be used, or additional water employed. Either of
• these two actions will change the water: powder ratio, adversely affecting material
• performance and automatically invalidating Fosroc‟s standard product guarantee.
• Conbextra HF is used for gap thicknesses from 10 to 125 mm. In cases of gaps reaching 350
• mm; 8 - 10 kg of 10mm clean silt free rounded aggregates can be added to 25 kg of
• Conbextra HF. In such cases adjust water added 5.5 – 6 litres to reach the required
• consistency
• Placing
• It is essential that the machine mixing capacity, material supply and labour availability is
• adequate to enable the grouting operation to be carried out continuously. This may require
• the use of a holding tank, with provision for gentle agitation to maintain fluidity.
• Immediately prior to placement, the mixed grout should be briefly agitated to release any
• surface tension. Place the grout within 15 minutes of mixing to gain the full benefit of the
• expansion process.
• Page 5 of 5
• constructive solutions
• Any bolt pockets must be grouted prior to grouting between the substrate and the base plate.
• Continuous grout flow during the grouting operation is essential. Sufficient grout must be
• available prior to starting, and time taken to pour a batch must be regulated to the time taken
• to prepare the next one.
• The mixed grout should be poured only from one side of the void to eliminate the entrapment
• of air, or surplus pre-soaking water. The grout head must be maintained at all times so that a
• continuous grout front is achieved.
• When the grout reaches the open side of the formwork, and rises above the underside of the
• base plate, pouring should continue slowly down the length of the base plate until completed.
• Finishing
• Wherever possible unrestrained “shoulders” are to be avoided. These have a tendency to
• crack and/or debond, due to their unrestrained nature.
• Curing
• On completion of the grouting operation, all exposed areas of grout should be thoroughly
• cured. For best results use Concure curing membrane, continuous application of water
• and/or wet hessian.
• C: Approval and variations
• This method statement is offered by Fosroc as a „standard proposal‟ for „Conbextra HF. It remains
• the responsibility of the Engineer to determine the correct method for any given grouting operation.
• Where alternative methods are to be used, these must be submitted to Fosroc for approval, in
• writing, prior to commencement of any work. Fosroc will not accept responsibility or liability for
• variations to the above method statement under any other condition.