Concrete pavement projects in California now have a clearer and more practical path for resolving pavement strength concerns. Caltrans recently issued CPD 26-5, Acceptance Method for Low Strength Concrete Pavement, announcing upcoming revisions to Section 40 of the Standard Specifications that will take effect October 19, 2026.
The new acceptance procedure was developed through the collaborative Caltrans Pavement & Materials Partnering Committee (PMPC) process, bringing together representatives from Caltrans Construction, the Office of Concrete Pavements, METS, contractors, concrete producers, and industry stakeholders. This partnership-based effort reflects a shared commitment to improving specification clarity, reducing disputes, and ensuring acceptance decisions are based on the actual in-place performance of concrete pavement.
Through this collaborative process, stakeholders identified the need for a standardized method to evaluate pavement strength when cylinder test results indicate potential noncompliance. The resulting specification revision establishes a consistent, nationally aligned procedure for assessing in-place compressive strength using pavement cores while maintaining the high quality standards expected for California’s transportation infrastructure
The change addresses a gap that emerged after Caltrans transitioned from flexural strength acceptance to compressive strength acceptance in 2021. While procedures existed for evaluating modulus of rupture using pavement cores, there was no standardized process for determining in-place compressive strength when cylinder test results indicated the pavement did not meet acceptance requirements. This often created uncertainty regarding how to evaluate the actual strength and quality of the completed pavement.
For contractors and agencies, the benefits are substantial. The new procedure allows project teams to evaluate the actual pavement in place rather than relying exclusively on cylinder specimens cast during construction. This creates a more objective framework for addressing low-strength test results, improves consistency in acceptance decisions, and may help avoid unnecessary disputes, corrective actions, or pavement replacement when the constructed pavement can demonstrate adequate in-place strength through core testing.
Importantly, contractors do not have to wait until the 2026 Standard Specifications are fully in effect to benefit from the new process. Through CPD 26-5, contractors on projects advertised before October 19, 2026 may request use of the new provisions through a change order when 42-day strength results do not meet acceptance requirements. The change order must be approved before coring, and coring locations must be approved by the resident engineer.
This specification update represents a positive advancement for California’s concrete pavement program. Developed through the collaborative PMPC process, the new provisions provide a technically sound, transparent, and practical method for evaluating pavement strength while maintaining quality assurance, reducing the potential for costly project disputes, and ensuring acceptance decisions are based on the performance of the pavement that is actually constructed in the field.
Additional Information:
https://dot.ca.gov/programs/construction/construction-procedure-directives-cpds