Key facts
Location: Dallas, TX
Replacement level: 35% OPUS SCM™
Application: Sidewalk
Volume: 206 cubic yards
The project
Terra partnered with Lithko in Dallas, TX to optimize a low-carbon concrete mix using OPUS SCM™ produced from locally sourced feedstock. The mix was developed to support the customer’s sustainability goals while maintaining the performance and constructability expected from conventional concrete systems.
The project consisted of a 206 cubic yard sidewalk placement using a concrete mix where OPUS SCM™ replaced 35% of the
Type IL Portland cement. The project evaluated the field performance, workability, finishing characteristics, and constructability of OPUS SCM™ under real-world commercial placement conditions.
Concrete performance
The concrete used for the project was designed for a 28-day compressive strength of 3,500 psi. Third-party testing confirmed
that the OPUS SCM™ concrete mix achieved and exceeded the strength target.
Placement occurred during early morning operations under field production conditions. An evaporation reducer was applied
during placement to support surface moisture retention and finish operations. The mix maintained targeted workability and air
content during placement. Initial set behavior and finishing response aligned with contractor expectations and the overall
placement was reported as comparable to Type IL cement concrete systems.
At a 35% replacement level, the mix achieved an estimated CO2 reduction of approximately 25% compared to a conventional
Type IL cement mix.
Performance data
| Test Parameter | Test Standard | Unit | Opus SCMTM @35% |
|---|---|---|---|
| Slump | ASTM C143 | inch | 7.5 |
| Air Content | ASTM C231 | % | 3.3 |
| Compressive Strength @7 days | ASTM C39 | psi | 2,400 |
| Compressive Strength @28 days | ASTM C39 | psi | 3,600 |
