Underwater Concrete Repairs at Pumped Storage Plant

Case description

A large pumped-storage hydroelectric power plant required underwater placement of rapid-curing, high-strength concrete to repair the intake structure apron situated at the bottom of the reservoir using barge-mounted concrete mixing and pumping equipment.


Based upon concrete performance specifications provided by the client’s engineering consultant, various materials and performance-enhancing admixtures were selected working in conjunction with local construction material suppliers.

The contractor assembled the project team and performed trial underwater concrete placement operations to test various concrete mix designs and optimize equipment operations.

Preparation of high-strength concrete was undertaken by a two-stage process of first preparing suitable cement grout mixtures (including all admixtures) using dedicated mixing equipment, followed by transfer of the prepared cement grout to secondary mixers for blending of aggregate materials prior to pumping.

Mixing and pumping equipment with appropriate capacity was selected by our grouting engineer to enable the required underwater scope of work to be undertaken by divers within a time frame of several hours while achieving the required concrete performance for rapid-curing and high-strength.

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