Located in Colombia, El Quimbo is a 151 m high concrete face rockfill dam. It is part of a run-of-river reservoir scheme for hydroelectric power generation. As such, joint waterproofing is of imperative importance.
To ensure water tightness at the horizontal joint face slabs/parapet wall and at the vertical joints of the parapet wall, Carpi patented external water stop made of SIBELON® geomembrane was selected.
After the first dam filling, opening varying from 18 to 34 cm horizontally, and 13 to 40 cm vertically, appeared. Such deformations caused the rupture of the external PVC bulb, revealing the compaction and partial cementation of the fly ash filling material.
A Carpi external water stop was selected to restore horizontal and vertical joint water tightness. It is composed of a support layer of technical textile and a waterproofing SIBELON liner with extra length to accommodate potential relative displacement. The waterproofing liner was sealed by a perimeter seal watertight to water in pressure, made by compressing the geocomposite with flat stainless-steel batten strips.
The flexibility of Carpi external water stops provides resistance to the possible opening of 700 mm horizontally and 100 mm vertically while ensuring complete water tightness. The designed configuration guarantees that the external joint water stop will withstand potential relative displacements between the face slabs and the parapet wall and the opening of the joints of the parapet wall.
