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DESCRIPTION

BITUMAT BITUTHENE 1000X HC is a technically advanced cold applied, flexible, preformed waterproof membrane comprising a strong, high density, multi-layer polyethylene film with superior physical properties and a thick elastic self-adhesive rubber/bitumen compound. The advancedcarrier film is manufactured by cross laminating and chemically bonding the layers together, to produce a film with increased dimensional stability, four times the tear strength and puncture resistance, and twice the impact resistance of traditional low density polyethylene films. The membrane has been designed and specially formulated to withstand the higher ambient temperatures encountered in tropical zones.

When used in conjunction with Servicised waterstops cast into the concrete shell, it will provide a high performance, chemically resistant and fully continuous waterproofing / tanking system for basements and sub-structures. It is supplied to site in rolls 1.5mm thick x 1m wide x 20m long (20 sq meters) and is unrolled sticky side down on to concrete blinding or concrete slabs, or bonded to primed vertical concrete faces.

Continuity is achieved by overlapping adjacent rolls by 50mm and firmly rolling. Being factory made, the thickness of membrane is constant throughout and is not subjected to variation by site labour as occurs with brush applied membranes. Bituthene 1000X HC is extremely flexible with typically 200% elongation and is capable of bridging shrinkage cracks in the concrete and will accommodate minor settlement during the service life of the structure.

Bituthene membranes should never be taken through load bearing brick / blockwork walls and must be linked with the damp proof course to prevent extrusion under load.

Decomposition of Concrete Background The arid desert conditions in the Middle East, combined with high temperatures and humidity encountered in coastal regions require special precautionary measures to be taken in placing good durable concrete. The excessive heat and drying winds cause plastic shrinkage cracking

BITUTHENE 1000X HC

High Performance Tanking Membrane System

unless mixes are carefully designed and proper curing techniques are adopted. The high concentrations of salts present in water, ground, atmosphere and aggregates cause chemical reactions to take place in the concrete which rapidly lead to its decomposition. The extremes of temperature and humidity accelerate the chemical attack and physical deterioration.

Soluble Salt Attack In the coastal flats and many desert areas, the ground water table is very near to the surface and salts may exist either in solution in the groundwater, or in the form of salt crusts on the surface. The salts which consist mainly of sulphates, chlorides or carbonates of calcium, magnesium and sodium, attack the concrete externally both below and up to a metre above ground level. The calcium aluminium hydrate in hardened concrete reacts with sulphate salts to produce calcium sulpho-aluminate crystals within the framework of the hydrated paste. As these crystals have a volume 227% greater than the original calcium aluminium hydrate crystals, the concrete cracks and deteriorates. A similar reaction occurs between magnesium sulphate and the calcium hydroxide of the cement paste: this yields crystals of gypsum with an increase in volume of 124%.

Salt-Laden Moisture Salt weathering occurs when humid air cools and salt-laden moisture condenses on the concrete and into the cracks and pores where the solution crystallizes. The extreme temperature cycles and drying winds create volumetric changes in the crystals and consequent expansive forces cause cracking and spalling with rapid deterioration.Any additional moisture, from a heavy dew etc. redissolves the salt. and the subsequent recrystallization will maintain this expansion / contraction cycle.

Design Concept Our waterproofing recommendations are based on the design concept that all reinforced concrete structures at or below ground in the Middle East require special design considerations to overcome local geological difficulties, and that external attack can be prevented by protecting the whole of the below ground works with a continuous layer of Bituthene 1000X HC, which is impervious and vapour resistant.

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