Q25™/Q5™ Silo Repair

Concrete silos spalling due to age and weather has become a huge problem. Conventional patching has only proven to be temporary at best. There has been no solution…until now. Wear-Con & Densit® have the solution. Q25™ is a shrinkage compensated high performance concrete with an extreme capability to bind to old, as well as new, concrete surfaces. Q25™ provides an impermeable barrier that effectively prevents penetration of chlorides and moisture. (For lining thicker than 40mm anchoring and mesh must be used.)

First the surface to be repaired is thourghly cleaned and the old rebar is primed. Extra vertical rebar is welded into place if the spalding is deep. Heavy expanded metal reinforcement mesh is welded on the new vertical rebar. This mesh is what gives Q25™ its support while being sprayed and while curing for lining thicker than 40mm. Thickness of Q25™ is critical in the application. The the mesh has to be positioned properly. Measurements are taken to ensure the final product will be correct.

The entire prepped area is soaked down with water to ensure a proper bond. Densit® Q25™ dry mortar is mixed with water in a batch mixer. When ready, the mortar is pumped to the spraying nozzle. Even and consistent spray application is used ensuring that no voids exist behind the mesh. Densit® Q25™ is applied in 5-40 mm thickness by use of wet spraying equipment on vertical as well as horizontal and even over-head surfaces. (For lining thicker than 40mm anchoring and mesh must be used.) Spraying continues until all mesh is covered completely. Densit® Q5™ is a thin topcoat applied over Q25™. Q5™ provides an absolute barrier that effectively prevents penetration of chlorides and moisture. Densit® Q5™ is applied in 3-8 mm thickness and is oversprayed past the Q25™ layer.

Wear-Con Densit® Curing Compound is a surface sealer that is applied to all Densit® wear protection products after installation to retain water in the lining throughout the curing period. It reduces shrinkage and thus also the risk of poor bonding and minimize crack formation. The Densit® Curing Compound must be applied as a uniform coating after surface preparation has been achieved. It will dry in approximately 4 hours depending on the temperature and moisture of the atmosphere.