Sustainable Concrete Waterproofing

Why are we waterproofing structures in the first place?

It seems obvious: whatever the structure is sheltering, we want to keep that dry.

At least that’s the reason in most cases.

Sometimes it might appear it doesn’t matter if the structure is not waterproof. Concrete is resilient and can withstand a high degree of weather exposure of itself. If the structure is not protecting something else, then perhaps it doesn’t need to be waterproof?

Well, it’s not so simple.

 

We need to think about the structure’s own durability.

Here’s something not so obvious: the contaminants and reactants that cause concrete to age and break down prematurely, are carried in and around the concrete by moisture. Chlorides, sulphates and other contaminants enter and move about the porosity of the concrete as solutions in water or water vapour.

This is why concrete impermeability equates to concrete durability. Block the entrance and movement of moisture, and you successfully protect the concrete from a wide array of negative contaminant attacks.

 

The hydrogel answer

This is where concrete hydrogels come in to play.

The formation of a C-S-H hydrogel can be induced within concrete, by the application or admixture of nanoparticle colloidal silica. This catalyst reacts with free lime and moisture within the concrete, closing up the porosity with fresh hydrogel. No foreign element is introduced into the concrete.

Why is this valuable? Because moisture, and therefore the contaminants in that moisture, can’t enter or move about – it is immobilized in the hydrogel formation.

 

The benefits of hydrogel admixtures

For maximum benefit, from day one, make sure to include the colloidal silica treatment in the mix at the construction phase!

The treatment is permanent, closing the porosity of the whole of the concrete as the pour cures.

There are operational benefits too: improved workability, reduced shrinkage, and enhanced flexural and compressive strengths.

Best of all, hydrogel treatments are completely safe for the environment.

Sustainability and the environment

We’ve ticked a couple of boxes here already.

    1) We’re making the concrete stronger, and last longer, which means less replacement concrete is required. Seeing as the cement manufacturing process is allegedly a major contributor to global carbon emissions, it’s good news if we can reduce our overall concrete usage by successfully maintaining existing structures.
    2) Hydrogels are safe for the environment. And for the living things in that environment, too!

Let’s move on to a new source of the key ingredient!

New sustainable source of colloidal silica

Silica is found in and under the ground – you are familiar with sand, for instance. Silica is a significant mineral emission from geothermal and volcanic activity.
And in many places where geothermal activity is found, it has been successfully captured for power production. New Zealand is one of those places.
Steam from under the ground is diverted to drive power turbines.

There’s a byproduct of that process – a build up of silica formation, which must be removed to keep the equipment operational.
That byproduct forms the basis of Markham’s new colloidal silica hydrogel treatment!
It’s a win-win situation.

The new CONQOR B50 waterproofing admixture is a fully sustainable and environmentally friendly product.
Furthermore, it has been extensively tested, with very positive results in pressure tests and increased concrete strengths.
As a bonus, it improves concrete rheology, making placement and handling easier for the teams on site.

• A WIN for the construction designer – helping meet project environmental requirements.
• A WIN for the construction team – saving time and money, and improving placements.
• A WIN for the asset owner – increasing structural durability and holistic concrete waterproofing.