About this Product
webercem pyratop is a two-part hydraulic cement based repair concrete consisting of a bag of the product and a smaller bag of special aggregate. When mixed together with the addition of water, it produces a rapid setting concrete with high early strength suitable for thin-bonded toppings or full-depth repairs up to 15m². It is dimensionally stable and has excellent abrasion resistance due to the use of hard granite aggregate.
Features and Benefits
▲ Complies with Highways Agency Specification HD27/04
▲ 25-30 minute working time at 20°C
▲ 45 minute set time at 20°C.
▲ Traffickable in 6 hours at 20°C and 18 hours at 10°C
▲ Shrinkage compensated
▲ Resistant to freeze/thaw conditions
▲ Can be used for winter work down to 5°C
▲ Excellent abrasion resistance
▲ May be extended with non-reactive 10 mm granite aggregate for full depth repairs over 75 mm depth
▲ Excellent strength gain after 6 hours at low temperatures
▲ No special bonding agent required
▲ Requires only the addition of water
Material Safety Datasheet
Declaration of Performance (DoP)
Preparation & Application
All concrete to be repaired should have a minimum characteristic strength of 25 N/mm² and a tensile bond strength of at least 1 N/mm². The surface preparation method should be carefully chosen so as to minimise the risk of micro-cracking in the parent concrete thus affecting the bond with the repair.
Mark out the area of concrete to be removed perpendicular and parallel to the axis of the concrete paving bay.
Saw cut around the perimeter of the repair about 25 mm deep, ensuring that the saw cut does not cut through any existing reinforcement. Saw cut in straight lines to provide a sound edge to work to. The edges of the saw cut area should be keyed to ensure good bond. For jointed slabs, saw full depth to provide a face for a new joint, avoid overcutting.
For more details on the design of patch repairs, refer to the Weber Technical Note : Concrete repair patches on horizontal surfaces for flooring and external paving.
Carefully break out the existing concrete without damaging the adjacent concrete. If the existing reinforcement is removed, leave sufficient rebar for a lap for tying in subsequent rebar and/or structural mesh a minimum of 450 mm or 35 bar diameters. Only cut back existing rebar where a dowelled joint is to be made.
Where a new dowelled joint is to be made, as specified by the structural Engineer, then drill holes of the appropriate size and depth for the dowels specified. Dowel bars shall be Grade 250 steel complying with BS 4449 and shall be free from any contamination, straight and with clean sawn ends, as approved by the engineer. The size and length of bar shall be specified by the engineer.
Prime and plug the holes with webertec EP TAG thixotropic resin anchor grout and insert the dowels/tie bars within the tolerances for alignment specified.
Where the full depth reinstatement adjoins a movement joint, install and fix expansion joint filler board. Reinstate the sub-base layer with approved granular material and replace any separation membrane as necessary.
Lap and tie any new reinforcement to that removed with minimum 450 mm or 35 bar diameters, whichever is the greater for longitudinal bars and 300 mm for transverse bars.
For full depth repairs all exposed reinforcement steel should be cleaned to BS 7079-A1 (equivalent to Swedish Standard SA 2½) and then primed with webercem bondcoat.
Clean and remove all oil, grease, dirt and loose debris from the area to be repaired. Thoroughly wet the prepared surface with clean water for at least 30 minutes prior to the start of mixing. Remove surplus water to achieve saturated, surface-dry concrete substrate.
Use only freshly opened webercem pyratop bags and a clean, forced-action mixer such as a twin screw mixer (shown here), a Creteangle or Baron mixer. The mixer capacity should be at least 30% greater than the quantity to be mixed ie minimum 50 litres for a single bag mix.
Locate the mixer close to the area to be repaired. Working time at 20°C is approximately 30 minutes. At lower temperatures, working time is increased, so it is advisable to keep material warm and use warm water in cold weather conditions. Charge the mixer with 2.5 litres of water, then add the whole bag of aggregate and stir for 30 seconds, followed by a gradual addition of webercem pyratop. Mix for 3 minutes. An additional 0.1 litres of water may be added if necessary and mix for a total of 5 minutes.
NB: Do not exceed maximum water addition of 2.6 litres water per unit.
The resultant mix is not flowable but thixotropic and can easily be tamped down a spread.
Bulking-out - For repairs over 75 mm thick, use a bulked out mix of the repair concrete as follows : use 2 bags of webercem pyratop and 3 bags of the crushed granite aggregate. Mix with 5.7 litres of water to yield 35 litres of bulked out rapid concrete.
The mixed material must be placed within 20 minutes of mixing and just after priming. Place, spread and compact webercem pyratop, ensuring full compaction at the edges by tamping.
Finish to the correct profile by steel or wooden trowel to seal the surface edges and saw cuts and finish to the required texture. The surface of slabs to be used as trafficked surfaces shall be brush-textured in a direction at right angles to the longitudinal axis of the carriageway. The texture shall be applied evenly across the slab in one direction by a brush not less than 450 mm wide. The texture shall be uniform both along and across the slab.
Setting time - Setting time at 20°C is approximately 45 minutes.
Winter working - webercem pyratop can be used down to 5°C provided cold weather working precautions are carried out. For applications below 5°C please contact Weber's Technical Services Department
Cure within 20 minutes of laying using an appropriate method such as wet hessian, polythene sheeting weighed down with flat boards or a proprietary sprayed-on curing membrane. Insulation blankets shall be used during cold weather working to ensure the surface temperature of Pyratop is kept above + 5ºC until the material has achieved final set.
Protect from frost.
Packaging, Health & Safety
webercem pyratop is now supplied in a two-part pack comprising a 25 kg bag of mortar and an 8.3kg bag of special granite aggregate.
Together they weigh 33.3kg and when mixed with 2.5 litres of water, yield 15.5 litres of rapid setting concrete.
Unbulked: yield per one unit of 33.3 kg webercem pyratop and aggregate is approximately 15.5litres.
Bulked: yield per 2 bags of webercem pyratop powder and 3 x 8.3kg bags of aggregate is 35 litres.
Storage and Shelf Life
When stored unopened in a dry place at temperatures above 5°C, shelf life of the 25 kg webercem pyratop bags is 6 months from date of manufacture. The shelf life of the aggregate is not limited.
Health and Safety
Contains cement (Contains chromium (VI). May produce an allergic reaction). Irritating to respiratory system and skin. Risk of serious damage to the eyes. May cause sensitisation by skin contact. Keep out of the reach of children. In case of contact with eyes, rinse immediately with plenty of water and seek medical help. After contact with skin, wash immediately with plenty of soap and water. Wear suitable protective clothing, gloves and eye/face protection.
Other products in the range
Fast-setting repair concrete for pavement patch or full-depth repairs
General-purpose, rapid-setting, cement-based bedding concrete
Shrinkage-compensated, rapid setting bedding mortar for the reinstament of road iron work and highway furniture
Polyester-based mortar for bedding and fixing manhole frames, kerb stones, airport lighting bases, ducting, drains and highway fixtures