For generations, curing concrete meant one thing: protect the surface. Contractors sprayed water, applied curing compounds, or covered fresh slabs with wet burlap—all in an effort to slow evaporation and prevent surface cracking. These methods became industry standard because they work on the top layer of concrete.

But modern concrete is not the concrete of decades past.
High-performance mixes, low water-to-cement ratios, faster schedules, tighter tolerances, and harsher service environments demand more from curing—and traditional methods simply cannot keep up.

Even the best surface curing regimen fails to address the deeper, hidden issue that undermines concrete before it ever reaches service: internal moisture loss.

If you want concrete that performs for decades rather than years, the answer lies in a new approach: Internal Curing, powered by advanced admixtures like E5^® Internal Cure—the first admixture proven to provide true internal curing of concrete.

The Fundamental Flaw in Surface-Only Curing

Traditional curing focuses exclusively on slowing surface evaporation, preventing the top layer from drying too quickly. Curing compounds form a temporary membrane. Water misting and wet coverings keep the surface damp. These steps are important—but they address only one half of the hydration challenge.

Below the surface, a very different process is taking place.

As concrete hardens, the cement hydrates and consumes internal mixing water. In today’s high-performance mixes—with deliberately low water-to-cement ratios—there is not enough internal water to fully complete hydration. As this water is consumed, self-desiccation occurs.

The result?

• Empty capillary pores

• Internal negative pressure

• Autogenous shrinkage

• Micro-cracking

• Loss of density

• Long-term durability issues

This internal moisture demand is far more significant than what occurs at the surface.

And here is the key problem:
External water cannot reach the internal pores fast enough or deep enough to replace what is being consumed.

Even with perfect surface curing, the core of the slab dries from the inside.

Surface Curing Penetrates Less Than One Inch

Water applied to the surface cannot penetrate dense, low w/c ratio concrete. Multiple studies and field results confirm that topical moisture rarely diffuses more than a fraction of an inch into the matrix. Even extended ponding—rarely done in modern construction—does little for slabs over 3–4 inches thick.

This means:

• The surface hydrates

• The core shrinks

The slab becomes structurally inconsistent, with built-in stress that eventually shows up as:

• Internal micro-cracks

• Curling

• Warping

• Reduced abrasion resistance

• Lower long-term strength

• Higher permeability

• Premature deterioration

Traditional curing solves drying shrinkage, but does nothing for autogenous shrinkage, which is the true driver of internal cracking.

Internal Curing: The Modern Solution That Cures Concrete From Within

Internal Curing provides a continuous internal source of curing water that supports the hydration process for the entire slab—not just the surface. Instead of fighting evaporation, Internal Curing addresses hydration demand directly at the source.

E5^® Internal Cure is the first admixture proven to deliver true internal curing by controlling the water of transport and water of convenience, ensuring complete hydration without reliance on topical methods.

This is not theory—it is verified through third-party testing and industry certifications.

What Makes E5^® Internal Cure Different?

1. Internal Reservoir System

E5^® is introduced at the ready-mix plant and disperses uniformly throughout the concrete. It functions as a microscopic network of internal water reservoirs. The stored water does not affect the fresh water-to-cement ratio.

2. Stress-Activated Moisture Release

As hydration progresses and internal pores begin to empty, capillary tension forms. This internal stress triggers E5^® to release moisture directly into the cement paste, counteracting autogenous shrinkage.

3. Complete Elimination of Surface Curing

Because hydration is maintained internally—not through external moisture—E5^® Internal Cure eliminates the need for:

• Wet curing

• Water spraying

• Burlap coverings

• Traditional topical curing compounds

This is validated through ASTM C156 testing, where E5^® qualifies as a concrete curing compound.

4. Uniform Hydration Across the Entire Matrix

Instead of a surface-strong / core-weak structure, concrete cured with E5^® achieves consistent hydration, producing:

• A denser matrix

• Lower permeability

• Greater compressive and flexural strength

• Higher hardness and abrasion resistance

Traditional vs. Internal Curing: Clear Answers to Common Questions

Do I still need topical curing compounds when using E5^®?

No. E5^® Internal Cure eliminates the need for wet curing and topical curing compounds. E5^® qualifies as a curing compound per ASTM C156-20 and has been verified by independent laboratories.

How deep does traditional curing actually penetrate?

Less than an inch.
The core of the slab remains unprotected and susceptible to autogenous shrinkage.

Does internal curing reduce strength?

Absolutely not.
Internal curing enhances strength by supporting more complete hydration. E5^®-treated concrete exhibits increased density, reduced permeability, and superior performance in abrasion and chemical resistance.

Can E5^® Internal Cure be used in all types of concrete?

Yes. According to the E5^® Internal Cure TDS, it can be used in:

• Pavements

• Parking garages

• Structural walls and columns

• Footings and foundations

• Civil infrastructure

• Interior slabs-on-grade

• Slab-on-metal-deck

E5^® is compatible with virtually all concrete applications.

The Durability Dividend: Why Internal Curing Outperforms Surface Curing

The transition from external to internal curing is about far more than convenience—it is about long-term durability, reduced maintenance, and lower life-cycle cost.

1. Dramatically Reduced Shrinkage and Curling

E5^® continuously supplies curing water from within the slab, minimizing shrinkage gradients and stress. The result is significantly reduced curling and warping.

2. Enhanced Finisher Control

E5^® reduces evaporation even in harsh environmental conditions—including low humidity, high winds, and direct sunlight—giving finishers greater control and consistency.

3. Superior Abrasion and Chemical Resistance

The E5^® Internal Cure + Catalyst system delivers extremely dense, hard surfaces suitable for high-traffic and commercial flooring applications, including proven performance as a moisture mitigation solution.

4. Proven Environmental Advantage

Eliminating traditional curing compounds significantly cuts carbon footprint.
For every 100,000 ft² placed with E5® instead of curing compound:

880 lbs of CO₂ are eliminated.

This aligns with industry sustainability goals without compromising performance.

5. Lower Permeability for Longer Service Life

Uniform hydration produces a denser microstructure that is more resistant to:

• Chloride ingress

• Water intrusion

• Freeze–thaw cycling

• Chemical attack

This directly protects reinforcement from corrosion and extends service life.

Modern Concrete Requires Modern Curing

Today’s concrete must endure:

• Heavier loads

• More aggressive environments

• Higher performance expectations

• Faster schedules

• Lower w/c ratios

Relying solely on surface curing is an outdated approach for modern infrastructure.

Internal Curing is the new standard.
And E5^® Internal Cure is the simplest, most reliable way to achieve it—without adding steps, slowing down your schedule, or depending on field labor.

The Cure to Concrete is Here.

Next Step for Concrete Professionals

If you're ready to eliminate traditional curing compounds, reduce cracking, improve durability, and accelerate finishing operations:

Download the E5^® Internal Cure Technical Data Sheet
Review features, dosage, environmental advantages, and specifications for replacing wet curing and curing membranes.

Or, for project-specific support:

Contact an E5 Expert to review your mix design and curing plan.