Desing System
Moor Placecase study: integrating Niobium-bearing structural steels in modern construction
The Niobium-enhanced steel allowed for long clear spans, maximizing the net lettable space within the building. This advanced material also minimized the need for extensive fire protection on the columns by allowing them to be infilled with concrete, and reduced the overall floor depth, enabling the addition of an extra floor. The total steel tonnage used in the construction was 2,900 tons.
Moor Place stands as a beacon of sustainability, having earned both a BREEAM “Excellent” and a LEED “Platinum” rating, testifying to its minimal environmental impact. Achieving these highest environmental standards in London was no small feat, thanks to the integration of high-performance facades, state-of-the-art HVAC systems, and a host of other conservation measures. Notably, Moor Place is among the select few buildings in London to attain such prestigious accolades. The project’s total cost amounted to £56 million, a worthy investment in a structure that exemplifies excellence in both design and sustainability, with Niobium at its core.
The steel columns, supplied by Tata Steel, exemplified excellence in both quality and performance. Fabricated from hot-finished circular hollow sections (CHS) composed of grade S355J2H in accordance with European product standard EN 10210, these columns boasted a minimum yield strength of 355 MPa and a toughness of 27 J at -20ºC. Notably, the inclusion of 0.030% Niobium by weight in the steel alloy not only met stringent strength and toughness requirements but also facilitated lower carbon content. This innovative use of Niobium microalloying not only enhanced weldability but also contributed to finer grains, thereby improving formability — a testament to the meticulous attention to detail and commitment to excellence evident in every aspect of the project.
construction techniques
Efficiency was a key focus in the steel frame’s design, using standard plate thicknesses to fabricate various beams. To optimize space and achieve the required 90-minute fire performance, both internal and perimeter columns were made from concrete-filled circular hollow steel sections, designed according to Eurocode 4 (EN 1994).
Niobium plays a prominent role in the evolution of steel construction techniques by enhancing the material’s strength and toughness. Niobium-enhanced steel results in lighter, more efficient structures, reducing construction timelines and costs. In the Moor Place building, this allowed for the use of a raft foundation, a faster and more economical alternative to deep foundations required for heavier concrete structures. These innovations highlight the importance of Niobium in sustainable buildings.