What is Non-Ductile Concrete?

By Shahab J. Shaolian · January 2, 2026

Non-ductile concrete refers to older concrete buildings constructed before modern seismic codes were adopted. These structures were typically built before 1977, when engineers had limited knowledge of how concrete should be reinforced to resist earthquakes. Unlike ductile concrete, which bends and absorbs seismic energy, non-ductile concrete is rigid and brittle, meaning it can crack and collapse suddenly under stress.

Key characteristics of non-ductile concrete:

• Rigid design: Reinforcement is minimal, making the building unable to flex during seismic shaking.
• Brittle failure: Instead of bending, the concrete fractures, leading to catastrophic collapse.
• Outdated construction era: Most were built before seismic safety standards were introduced in Los Angeles.

Why is it Dangerous in Los Angeles?

Los Angeles sits on multiple active earthquake faults, including the San Andreas and Newport-Inglewood. With seismic activity inevitable, non-ductile concrete buildings pose a major risk. According to a Los Angeles Times analysis, more than 1,000 concrete buildings in Los Angeles and hundreds more across the county may be at risk of collapse in a major earthquake.

The danger lies in:

• Collapse risk: These buildings can fail suddenly, trapping occupants inside.
• High population density: Many non-ductile concrete structures are apartments, offices, and schools in busy neighborhoods.
• Economic impact: Beyond loss of life, collapses could devastate businesses and housing security.

Los Angeles Ordinance and Seismic Safety

In 2015, Los Angeles passed Ordinance 183893, requiring owners of non-ductile concrete buildings to retrofit their properties. This law was inspired by devastating earthquakes in Northridge, Mexico City, and Christchurch, where non-ductile concrete buildings collapsed.

Compliance requires:

• Checklist submission within 3 years of notification.
• Engineering evaluation to determine retrofit needs.
• Mandatory retrofitting to meet seismic performance standards.

At SKS Construction, we specialize in earthquake retrofitting, balcony repair, subterranean waterproofing, and structural restoration across Greater Los Angeles. Don’t wait until the next big quake exposes your building’s vulnerabilities.

📞 Contact SKS Construction today to schedule a consultation and protect your property, your tenants, and your investment.

Shahab J. Shaolian (MS, PE) is the Principal Engineer overseeing structural and architectural design at SKS Construction. He holds a bachelor’s degree in Civil Engineering from Cal-State Northridge and a master’s degree in Architectural Engineering from Cal-Poly San Luis Obispo. His experience includes seismic retrofit, multi-residential, mixed-use and commercial projects.

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