Low-carbon cement without compromise

A one-for-one replacement for ordinary Portland cement (OPC)

Sublime Cement™, produced by our post-carbon process, adheres to strict industry-accepted standards.

This highly engineered, low-carbon cement has similar (or better!) ultimate strength, durability, slump, and set time as the cement we use today for our buildings and infrastructure.

Our ASTM C1157-compliant cement will be the first to commercial scale that approaches “true-zero” carbon — rather than just “net-zero” — by avoiding CO₂ emissions in the first place and foregoing the need for carbon capture and storage.

1:1

The needs of the construction ecosystem are at the center of our work. Sublime Cement^TM is a drop-in replacement for today’s portland cement, creating a frictionless replacement for ready-mix concrete producers that meets or exceeds ASTM C1157 standards.

Sublime Cement™ manufacturing doesn’t emit CO₂ that then needs to be cleaned up with expensive, complex carbon capture and storage (CCS) infrastructure. Because we replace the kiln, we can ultimately scale down the cost to match the kiln, without reliance on carbon credits.

We are developing the least expensive, most decarbonized cement

CO₂ Impact

Avoids fossil fuels

Drop-in replacement

for OPC in most applications

Cost parity

at scale

Scalability

% of global supply potential

Sublime Cement™

Cement today (OPC)

OPC + Carbon Capture

Supplementary Cementitious Materials

Carbonated / CO₂-Cured

Ideal

Suboptimal

Insufficient

Sublime Cement^TM

CO₂ Impact

Ideal

Drop-in Replacement

for OPC in most applications

Ideal

Scalability

% of global supply potential

Ideal

Avoids fossil fuels

Ideal

Cost Parity

at scale

Ideal

Cement today (OPC)

CO₂ Impact

Insufficient

Drop-in Replacement

for OPC in most applications

Ideal

Scalability

% of global supply potential

Ideal

Avoids fossil fuels

Insufficient

Cost Parity

at scale

Ideal

OPC + Carbon Capture

CO₂ Impact

Ideal

Drop-in Replacement

for OPC in most applications

Ideal

Scalability

% of global supply potential

Suboptimal

Avoids fossil fuels

Insufficient

Cost Parity

at scale

Insufficient

Supplementary Cementitious Materials

CO₂ Impact

Suboptimal

Drop-in Replacement

for OPC in most applications

Ideal

Scalability

% of global supply potential

Suboptimal

Avoids fossil fuels

Suboptimal

Cost Parity

at scale

Ideal

Carbonated / CO₂-Cured

CO₂ Impact

Suboptimal

Drop-in Replacement

for OPC in most applications

Suboptimal

Scalability

% of global supply potential

Suboptimal

Avoids fossil fuels

Insufficient

Cost Parity

at scale

Ideal

Sublime Cement™ meets or exceeds the strength and durability of traditional cement

Sublime Cement™ delivers across key durability characteristics

DURABILITY TEST

RELATIVE PERFORMANCE TO OPC

Alkali-Silica Reaction (ASTM C1260/C1239, AASHTO T380)

Much Better

Rapid Chloride Permeability Test (RCPT) (ASTM C1202)

Much Better

Electrical Surface Resistivity (AASHTO T358)

Better

Drying Shrinkage of Concrete (ASTM C157)

Better

Sulfate Attack (ASTM C1012)

Better

Freeze-thaw resistance (ASTM C666)

Equivalent

Sublime Cement™ 28-day strength outperforms that of Massachusetts regional benchmark mixes

Low carbon,
low friction

Third party validations ensure our performance, safety, and emissions reduction impact.

American Engineering Testing ensured our product meets ASTM C1157, the standard performance specification for hydraulic cement.

Our Safety Data Sheets ensure our product complies with OSHA’s Hazard Communication Standard 29CFR1910.1200 and can be safely handled just like the cement the world is used to.

Climate Earth completed our screening life cycle assessment (LCA), validating our process’ path to a >90% reduction in cement’s global warming potential.

We are thoughtfully validating our product in partnership with the construction industry

The global construction industry is rightfully mindful of safety and cautious about new materials. We’ve developed a comprehensive validation process — that starts in our lab and ends in the field — to earn their trust.

Our technology is
lab and field ready

Here’s how we got there

Characterization of materials

Calorimetry tests heat of hydration, indicators of early-age behavior and strength development.

Mortar & micro-concrete

We test for flowability, compressive strength, and admixture compatibility.

Concrete

We test for the concrete’s fresh and hardened durability properties.

Third-party validation

External, ASTM-validated labs test our material across strength and durability parameters.

Ready-mix lab trials

Local ready-mix partners test our cement’s performance in their concrete mixes.

Small-batch field trials

We ensure our material can mix and pour out of a truck and set and finish when placed by concrete contractors.

Field pours

This all leads up to field construction projects, where our material is mixed at the batching plant, transported in ready-mix trucks, pumped, placed, and finished into a final hardened concrete slab.

Mortar & micro-concrete

We test for flowability, compressive strength, and admixture compatibility.

Third party validation

External, ASTM-validated labs test our material across strength and durability parameters.

Small-batch field trials

We ensure our material can mix and pour out of a truck and set and finish when placed by concrete contractors.