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Understanding a Crystalline Waterproofing Specification

When receiving a specification for “crystalline waterproofing” or “integral waterproofing”, there are a number of factors to consider. The product choice made can directly affect the quality of the concrete. Using the wrong waterproofing product for the job at hand can compromise quality, or even affect the concrete producer’s profit per unit.

What Are Integral Waterproofing Systems? 

These systems work within the concrete itself to make the entire concrete structure a waterproof barrier

There are two main types of integral waterproofing systems: the hydrophilic and the hydrophobic systems.

• Hydrophilic systems (or PRAHs) typically use a crystallization technology (Crystalline Waterproofing) that reacts with water or moisture to create insoluble crystals, which block the pores and capillaries within the concrete, leaving it impervious to liquid. They perform exceptionally well in below grade structures or when facing hydrostatic pressure.
• Hydrophobic systems (or PRANs) use fatty acids to create a water repellent layer within the pores, reducing water absorption. These systems repel water and are recommended for use in above grade structures only.

FOLLOWING THE SPECIFICATION When You Get the Opportunity to Select a Waterproofing Admixture, Just What Are You Selecting?

Crystalline-based systems typically come in a dry, powdered form and are hydrophilic in nature. Unlike their hydrophobic counterparts, crystalline systems actually use available water to grow crystals inside concrete, effectively closing off pathways for moisture that can damage concrete. They block water from any direction because the concrete itself becomes the water barrier.

In contrast to water repellents, crystalline technologies enable self-sealing. The admixture is a blend of cementitious and proprietary chemicals that actually work with the available water in concrete to form insoluble crystals. These needle-like crystals grow until all pores are blocked and no water can penetrate the concrete. The crystalline formula can allow concrete to self-seal hairline cracks up to 0.5 mm (0.02 in.), even years after the original construction.

What Does This Mean to the Concrete Producer?

By selecting a hydrophilic crystalline waterproofing admixture in the appropriate circumstance, the concrete is optimized for the job. This means that not only is the quality and performance of the product improved – but the bottom line of the concrete producer’s profit and reputation are positively influenced.

Many concrete producers already familiar with this type of crystalline waterproofing have enhanced their product line with a branded, waterproof mix. By including a hydrophilic crystalline admixture they can rely on, many have multiplied their profit per cubic meter.

Concrete that is waterproofed using a hydrophilic crystalline admixture affords other benefits, too. It contains no VOCs from this admixture, and can be easily recycled when demolition occurs. Any contractor or owner looking to obtain LEED points, or reduce the environmental impact of their project, can benefit in the short and long term by using concrete with this type of waterproofing.

Short Term Benefits:

• Reduces site disturbance
• Less excavation is required because crystalline waterproofing admixture is added directly to the concrete mix. No need to excavate to accommodate space for workers applying physical membranes.
• Reduces waste on the job-site
• Hydrophilic crystalline admixtures often come available in custom sized pulpable bags, which are added directly to the ready-mix truck.
• Contains no Volatile Organic Compounds (VOCs)
• Many hydrophilic crystalline admixtures contain no volatile organic compounds, and do not affect air quality.

LONG TERM BENEFITS:

Safe to Use with Potable Water
Many reputable manufacturers of hydrophilic crystalline waterproofing admixtures have obtained certification from all over the world by various agencies as safe for use with portable water and by NSF to NSF/ANSI Standard 61 Drinking Water Components – Health Effects.

Creates a Recyclable Concrete
While membrane coated concrete goes straight to the landfill, concrete made with hydrophilic crystalline admixtures can be easily recycled post demolition, eliminating waste.

Permanent Solution
Crystalline technology will last the life of the concrete, growing stronger over time. These types of concrete waterproofing products contribute to the overall durability and life expectancy of a building by stopping corrosion, increasing freeze/ thaw durability, and protecting against chemical attack, carbonation and other detrimental effects.

When selecting a product for an integral of crystalline specification, taking the time to understand how the selection will make difference on the end product is critical. Selecting a product that will benefit the quality of the concrete, the projects intention, the producer’s bottom line, and the customer’s satisfaction should always be the objective.

Source: Virgina Ready-Mixed Concrete Association