Hot-applied, rubber bitumen sealant
flexoplastic B is a hot pour, rubber modified bitumen joint sealant.
Uses
For sealing low movement horizontal joints in:
- Trafficked premix and concrete surfaces where a high degree of resistance to grit penetration is required and joint movement is limited
Advantages
flexoplastic B is a hard resilient sealant which:
- Resists ingress of grit
- Protects arises of joints
- Extends the life of a road where cracks would normally require
the road to be either resealed or re-laid
Surface Preparation
When preparing cracks on roads, the crack should be opened up to a minimum width of 5 mm to allow the hot bitumen to penetrate into the crack. Dust, grit and loose stones must be blown out with dry, oil free, compressed air.
When sealing joints on horizontal surfaces of a water retaining structure, the joint should be dry and care should be taken to ensure that the joint filler provides adequate support for the flexoplastic B and that no void exists between the filler and the joint walls.
Polystyrene and closed cell polyethelene are not suitable fillers. The performance of the seal is largely dependent on the thoroughness of the preparation.
All old sealing compound, dust, scale, grit and loose stones must be removed and cement laitance scoured from the wall joints. Where possible, preparation by grit blasting is recommended, particularly if conditions are severe and a high degree of efficiency is required.
Blow out joints with dry, oil free compressed air. Refer to the “Preparation of Surfaces” datasheet for further information.
Typical Physical Properties
| Ring and ball | 85°C (typical value) |
| Penetration @ 25 °C | 42 mm (typical value) |
| Colour | Black |
| Pour temperature | 185 °C to 195 °C |
| Max. temp. to which product may be heated | 195 °C |
| Relative density | 1,02 |
| Movement tolerance | 5% of neutral joint width |
| Chemical resistance | Will resist most salt solutions, dilute acids and alkalis |
| Trafficable Cure | 2 hours |
Bonding/Primimg
bituprime must be used with flexoplastic B if applying to concrete. The primer must be completely dry (drying will take 4 – 24 hours depending on the weather). No primer required on bituminized fi nishes, i.e. pre-mix, etc.
Preparing flexoplastic B
The bag should be laid on a flat, clean surface and the bottom seal cut with a sharp knife. The outer layers of paper should be torn away and the inner layer stripped off, working from the bottom of the bag. It is essential that appropriate equipment is used for melting flexoplastic B to ensure that its subsequent performance is not impaired by damage caused when heating, or through pouring at the wrong temperature.
The heating vessel, e.g. melter pourer, should be fitted with a thermometer so that correct pouring temperatures can be observed. The melting
compartment should be either oil jacketed and equipped with a means of stirring, or if directly heated, equipped with an efficient motor-driven
agitator to ensure that the compound temperature is uniform and to prevent damage from localized hot spots.
NOTE: No primer or other foreign matter must be allowed in the pre-heater or melter pourer.
First, the compound should be cut into small pieces using a heated shovel blade. Melt a few pieces of compound and gradually add more pieces to
the molten material, stirring continuously. When the compound reaches pouring temperature, it should be discharged into joints as soon as possible.
In practice, small quantities of flexoplastic B, cut up with a heated shovel blade, can be melted in small directly heated vessels, gradually adding
more pieces to the molten material and stirring continuously. In such cases greater care must be taken to ensure that the compound is not damaged by overheating. The safe heating temperature for flexoplastic B temperature for prolonged periods or exceeding the recommended temperature must be avoided, since this can cause degradation of the rubber, which will result in a lack of flexibility and poor performance in cold weather.
Coverage
A 25 kg bag of flexoplastic B will produce approximately 24,5 liters. To calculate the yield from a 25 kg bag of flexoplastic B use the
formulae:
1 000 x 25 (weight of a bag) = M
W x D x 1,02 ( Spec. Dens.)
where:
W = width in mm
D = depth in mm
M = meters
No allowance has been made for waste.
Application
The correct pouring temperature for flexoplastic B is between 185 °C to 195 °C.
When the compound reaches pouring temperature it should be discharged into joints as soon as possible, preferably within two hours. It may be necessary to heat the spout of the melter pourer at the beginning of work, but this must only be suffi cient to free any accumulated compound.
Extra care should be taken in cold weather. The cold surfaces of the joints may cause rapid chilling of the compound. To help compensate for this, the compound should be poured at the top limit of the pouring temperature range.
Frost may give concrete a deceptively dry appearance. It is therefore inadvisable to seal in such conditions, unless the surfaces can be dried
out first with a gas torch. Work should be planned so that the melter pourer can be emptied by the end of the day. If, due to inaccessibility, a
melter pourer cannot be used, flexoplastic B should be poured from a boiler filler type galvanised watering can, which should be insulated
to conserve heat and used not more than two-thirds full to ensure neat pouring. When pouring into deep or narrow joints, the level of
the compound may sink a little on cooling. Therefore, it is sometimes preferable to pour in two layers to ensure that the joints are uniformly
filled.
Re-melting
Compound that has been heated and then allowed to cool completely, must not be re-melted and must be discarded.
On the other hand, it is permissible to reheat material which has not fallen below 93 °C (200 °F) i.e. which is still fluid enough to be stirred.
Cleaning
Care should be taken to ensure that the flexoplastic B has cooled sufficiently on the equipment to allow it to be scraped out of the
heating vessels and off the tools. Once cool, the bitumen residue can be removed with abe® super brush cleaner.
Protection On Completion
The joint sealant will require protection until it has cooled to ambient temperature.
Model Specification
Rubber-modified, hot-pour crack sealant for premix surfaced roads and concrete joints.
The sealant will be flexoplastic B, a hot-applied rubber modified bitumen compound applied in accordance with the recommendations
of a.b.e.® including bituprime primer. The compound will have a typical penetration of 42 mm at 25 °C and a typical softening point of
85 °C.
Packaging
flexoplastic B is supplied in 25 kg polyethylene lined paper bags.
Handling & Storage
This product has a shelf life of 24 months if kept in a dry cool place in the original packaging. In more extreme conditions this period might be
shortened.
Health & Safety
Due to high pouring temperatures, adequate protective clothing, including gloves should be worn. Ventilation of covered working environments is
essential to prevent breathing in of fumes. flexoplastic B does not taint water.
Important Note
This data sheet is issued as a guide to the use of the product(s) concerned.Whilst a.b.e.® endeavours to ensure that any advice, recommendation,
specification or information is accurate and correct, the company cannot accept any liability for application – because a.b.e.® has no direct or
continuous control over where and how a.b.e.® products are applied.
Further Information
Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total
requirements.
a.b.e.® has a wealth of technical and practical experience built up over the years in the company’s pursuit of excellence in building and construction
technology.