Project Description

Problem:

City Staff emptied and cleaned the Digester over a two-week period for inspection purposes. Upon inspection it was determined that the walls of the digester were showing signs of concrete deterioration.

Solution:

Due to the very limited time that the Digester could be off-line and to maintain the structural integrity of the digester walls, the Mainstay Composite Liner was the product chosen to rehabilitate the structure.

Surface Prep:
– All areas to be lined were prepared using abrasive blasting and pressure washing to remove all contaminated and loose material.

Surface Rebuilding and Corrosion Protection:
– Mainstay ML-72 Microsilica Mortar was mixed and applied to the digester walls with a shotcrete nozzle where it was then hand troweled and finished with a sponge to achieve a textured finished.
– 100 mils of Mainstay DS-5 Epoxy was applied to the mortar for protection against further corrosion.
– The use of Mainstay DS-5 Epoxy over Mainstay ML-72 Restoration Mortar creates a lining that cures into a strong, highly corrosion resistant surface free of pinholes, holidays and voids.

Benefit:

This digester rehabilitation project not only restored the deteriorated concrete but also protects from further corrosion giving this structure many more useful years of service life.

Location:
Lebanon, Oregon

Installation Date:
September 2020

Owner:
City of Lebanon Public Works