Cooling Tower Basin Lining

The challenge

A cooling tower cold-water basin holds the circulating water before it heads back to the plant, so the floor and walls have to stay sound and tight. Over time the concrete spalled and cracked at the floor and at the base of the walls, and the treated water started working into the slab and seeping out through the cracks. That loss of water and treatment chemistry matters because it undercuts the slab, carries the corrosion path deeper into the concrete, and means the basin can no longer be trusted to hold what it is supposed to hold. The owner needed the basin sealed and back in service without tearing out and recasting the structure.

The Belzona approach

Chipping out the unsound and delaminated concrete down to a solid base gives the repair something to grab. The spalled floor and wall sections are rebuilt with a Belzona 4000 Series repair mortar that cures in a damp basin, which lets the surface be worked without fighting to get it bone dry first. The floor and walls are reprofiled back flat and even, then the whole basin is lined with a Belzona 5000 Series coating that holds back the circulating water and the treatment chemistry. Taking the cracks, the rebuilt areas, and the sound concrete under one continuous lining closes off the leak path the basin had developed and leaves the owner a single barrier across the floor and walls.

1. Assess and chip outSounding the floor and walls finds the spalled and delaminated concrete and the active cracks, and the unsound material is chipped back to a solid base.
2. Surface prepThe exposed concrete is cleaned and profiled so both the rebuild mortar and the lining bond to a sound surface.
3. Rebuild floor and wallsA damp-cure repair mortar rebuilds the spalled floor and wall sections, taking in the basin without needing the concrete fully dried out.
4. Reprofile and lineThe surface is reprofiled flat, then the basin floor and walls are lined with a coating that seals the cracks and holds back the circulating water and treatment chemistry.
5. Inspect and return to serviceThe lining is checked for continuity over the repairs and the cracks, and the basin is turned back over to the plant.