NIST Engineers Unveil Five New Precast Concrete Connection Designs to Boost Building Resilience

USA: NIST Engineers Unveil Five New Precast Concrete Connection Designs to Boost Building Resilience

In September 2025, researchers at the National Institute of Standards and Technology (NIST) announced five innovative connection systems for precast concrete structures, intended to increase a building’s ability to withstand sudden loads such as earthquakes, floods, or explosions. The designs were evaluated at NIST’s structural testing laboratory in Gaithersburg, Maryland, where hydraulic actuators applied more than 34 metric tons of force to prototype connections.

Background on Precast Concrete

Precast concrete is manufactured in controlled factory settings, allowing for consistent quality and reduced on‑site labor. While this method lowers construction costs and improves material uniformity, it creates a larger number of joints that can become the weakest points in a structure, especially under extreme stress.

Structural Fuse Concept

The new connections incorporate “structural fuses”—deliberately weak steel elements that stretch before breaking, similar to an electrical fuse. By directing tensile forces into these fuses, engineers aim to prevent brittle concrete from cracking catastrophically, thereby limiting the spread of damage after a localized failure.

Full‑Scale Testing and Performance

Five‑eighths‑scale prototypes featuring metal plates, bolted brackets, and peg‑in‑hole systems were instrumented with sensors and subjected to incremental loading. All five designs survived the applied forces, demonstrating the ability to maintain structural integrity even when a supporting column was removed.

Industry Partnership

NIST collaborated with the Precast Concrete Institute (PCI) to ensure the designs are compatible with existing manufacturing processes. Feedback from PCI members helped shape the final configurations, making the connections feasible for mass production and straightforward on‑site assembly.

Potential Impact on Building Safety

If adopted widely, these connection methods could reduce the likelihood of disproportionate collapse—a phenomenon where localized damage triggers a cascade of failures throughout a building. The research supports ongoing efforts to enhance the resilience of critical infrastructure and may influence future building codes.

This report is based on information from NIST, licensed under Public Domain (U.S. Government Work). Source: Official U.S. Government release.