Data centers are among the most demanding concrete environments built today.
Unlike commercial floor slabs, data center floors must withstand:
Concentrated rack and point loads
Ultra-tight FF/FL tolerances for automated equipment
Sensitive resinous and ESD flooring systems
Strict limits on vibration and slab movement
Zero tolerance for unexpected shutdowns
In these facilities, “normal” shrinkage or hairline cracking isn’t cosmetic—it can compromise uptime, equipment performance, and flooring integrity. The challenge is that the very mix designs used to achieve higher performance (low water-to-cement ratios, high strength, and lower permeability) are also the ones most susceptible to autogenous shrinkage, self-desiccation, and internally generated stress.
Traditional surface curing methods do not solve this issue because the problem begins inside the concrete, not at the surface.
Internal curing technologies—including nano-silica admixtures such as E5® Internal Cure—are designed to help stabilize moisture throughout the slab depth, making high-performance data center floors flatter, more stable, and more predictable long-term.
Concrete experiences two main forms of shrinkage:
Moisture leaves the slab and evaporates into the environment, causing the surface to contract.
The cement is consuming water during hydration, and internal relative humidity drops—even if the slab is sealed.
Low w/c mixes used in data centers begin with very little free water. As hydration progresses:
Capillary pores empty
Internal RH drops
The cement paste contracts
Internal tensile stress builds
This shrinkage often presents as:
Random cracking between joints
Joint widths widening beyond design intent
Curling or warping at slab corners
Loss of FF/FL
Higher deflection under load
Data center slabs are especially vulnerable because:
They are thicker (which makes re-wetting nearly impossible)
They contain dense reinforcement
They support higher, concentrated loads
They often require precision-level flatness
That means shrinkage isn’t just undesirable—it is a direct threat to operations.
Traditional curing attempts to slow evaporation at the surface:
Water spraying
Wet blankets
Curing compounds
These methods help with drying shrinkage, but do little for autogenous shrinkage, which occurs deep within the paste.
Once internal water is consumed:
Hydration slows
The microstructure becomes stressed
The slab shrinks from within
Volume change becomes uneven
And because thick data center slabs cannot be effectively re-wetted from the surface, hydration remains incomplete and stress continues to build.
This leads to:
Higher permeability
Unhydrated cement
Micro-cracking
Curling and warping
Long-term dimensional instability
Surface curing protects the top ⅛–¼ inch.
The structural behavior of the slab comes from the other 99%.
Internal curing addresses shrinkage at its source by storing curing water inside the concrete and releasing it only when the cement needs it.
Internal curing admixtures—such as the nano-silica system used in E5® Internal Cure—help control both:
The water of transport (excess water needed for placement)
The water of convenience (water needed for hydration)
By managing these internal moisture phases, internal curing supports hydration throughout the slab depth. Benefits include:
More complete hydration
Reduced autogenous shrinkage
More uniform internal RH
Less curling at joints and slab edges
Lower permeability
Fewer micro-cracks
According to the E5® Internal Cure technical documentation, this process can also eliminate the need for wet curing and topical curing compounds while supporting deeper hydration and reducing drying shrinkage.
For data center slabs, this micro-level moisture control is essential.
Shrinkage is a function of internal stress.
Internal stress is a function of internal water availability.
When hydration consumes water faster than it can be replenished:
Capillary tension forms
Pore structure contracts
Autogenous shrinkage increases
Tensile stresses accumulate
Micro-cracking, warping, and curling occur
Internal curing reduces this chain reaction by maintaining internal humidity, helping the slab hydrate more uniformly with less volumetric strain.
The result?
Reduced shrinkage
More dimensional stability
Less joint widening
Better long-term FF/FL retention
Field data and independent research have shown that internal curing can significantly reduce shrinkage-related performance issues in dense, low w/c concretes commonly used in heavy-load environments.
Shrinkage isn’t just a materials-science issue.
In data centers, it directly impacts:
Joint movement or curling can cause rocking, differential deflection, or out-of-tolerance point loading.
AGVs, dense racking systems, and laser-guided equipment demand extremely tight tolerances.
ESD, epoxy, and resinous flooring are highly sensitive to cracks, pH, moisture migration, and surface movement.
Repairs often require shutting down sections of the facility—unacceptable in mission-critical environments.
Internal curing helps reduce these risks by limiting shrinkage from the inside out, stabilizing slab geometry, and supporting more predictable long-term performance.
Paired with surface-level moisture and pH control strategies (such as those provided by Catalyst-type nano-silica treatments), internal curing supports the full flooring assembly—not just the concrete substrate.
Drying shrinkage: moisture leaves the slab to the environment.
Autogenous shrinkage: hydration consumes internal water, lowering internal RH.
Internal curing primarily targets the autogenous component.
Some internal curing admixtures—such as E5® Internal Cure—are designed to eliminate wet curing and traditional curing compounds while still retaining moisture for hydration.
Good placement and protection practices still apply.
Yes. Internal curing has been documented extensively in academic literature, including studies validating shrinkage reduction, hydration efficiency, and improved dimensional stability. E5®-related research includes independent lab verification and DOT testing programs.
Reducing shrinkage and improving internal moisture uniformity helps stabilize flooring substrates. This supports long-term adhesion and reduces movement-related failures.
High-performance data center slabs require more than surface curing.
Low w/c mixes are inherently prone to autogenous shrinkage because the internal moisture supply is limited. The most serious stress and cracking issues begin inside the concrete, long before surface curing can help.
Internal curing provides a built-in moisture reservoir that supports hydration from within, reduces shrinkage, and stabilizes the slab for long-term performance.
Nano-silica–based systems like E5® Internal Cure are examples of how internal curing can be integrated into modern mix designs to help data center floors remain flat, stable, and reliable over decades—not just years.
Access mix design recommendations, internal curing specifications, testing data, and the complete submittal package to support high-performance data center slabs.
Inside, you’ll find:
Internal curing requirements for low w/c, mission-critical slab designs
Guidance for reducing autogenous shrinkage and internal stress
Documentation on moisture management and pH stability
Verification testing and ASTM references
Support resources for FF/FL, shrinkage control, and slab durability
Need project-specific guidance?
If you’d like to review mix design parameters, loading criteria, or curing strategies for an upcoming data center project, connect with a technical specialist to discuss possible solutions.