Carpi waterproofing geomembrane systems are used on these dams at the upstream face, to restore watertightness to the entire face, or at leaking zones, or at cracks.
The benefits are :
stop water infiltration, bridge joints and large cracks
reduce/prevent the formation of uplift pressures
provide freeze/thaw protection to the face
promote a substantial reduction in water content of the dam body (dehydration)
may assist in retarding alkali-aggregate reaction (AAR)
can withstand seismic events, bridging potential openings of cracks and fissures
minimum surface preparation is required
can be quickly installed, in the dry and underwater
has a well documented long durability
Carpi has lined more than 55 large concrete dams of all types. The geomembrane is generally exposed. All installations, some of which are more than 30 years old, prove the system’s excellent durability, even in the most severe climates.
In RCC dams, due to construction procedures and materials, possibility of water infiltration from the reservoir is higher than in conventional concrete dams. The main causes are horizontal lift joints, contact between the RCC and the conventional concrete, higher permeability of the concrete mix.
Carpi waterproofing geomembrane systems are used in RCC dams in new construction, where the geomembrane provides the watertight element while the RCC concrete provides the static function, and in rehabilitation, to restore watertightness at the upstream face or at leaking joints or at cracks.
The benefits are :
in new construction, allow reducing the cementitious contents in the RCC mix, reduce the hydration heat with less risks of cracking, make the entire construction procedure easier and therefore more reliable, can be quickly installed, reducing construction times and costs, and allowing earlier impounding
in new construction and rehabilitation, stop water infiltration, bridging lift joints and connections with conventional concrete elements, reduce/prevent the formation of uplift pressures, provide freeze/thaw protection to the upstream face, can withstand seismic events, bridging potential opening of cracks and fissures, well documented long durability
Carpi has lined more than 25 large RCC dams. The geomembrane can be left exposed or be covered.
Traditional impervious elements in earth and rockfill dams are concrete or bituminous concrete facings, or clay or bituminous concrete cores. As the facing deteriorates, or the core does not have the expected behaviour, water infiltration increases. With age and increased water infiltration, drains may become clogged because of transported fines. Uplift pressures increase and dangerous internal erosion and potential piping of the dam may occur.
Carpi waterproofing geomembrane systems are used on embankment dams in new construction, where the geomembrane provides the watertight element at the upstream face or at the core, and in rehabilitation, to restore watertightness over the entire face, or at leaking zones, or at cracks.
The benefits are :
In new construction they can substitute materials not available in needed quantity/quality/at reasonable cost, providing a valid alternative to concrete facings or bituminous concrete facings, or to clay or bituminous concrete cores; have higher capability to accept settlements and differential movements, can be constructed with materials of limited properties, simplify construction, reduce construction times and costs, allowing earlier exploitation
In new construction and rehabilitation, stop water infiltration, provide watertightness even when large settlements occur, provide watertightness at connections embankment/concrete appurtenances, can withstand seismic events, reduce/prevent the formation of uplift pressures, avoid the migration of fines in the core, prevent internal erosion and piping
Carpi has lined 40 large embankment dams, maximum water head 198 m.