Synergizing Sustainability and Structural Innovation: A Critical Review of Steel-CLT Composite Floor Systems in Modern Construction

The pressing necessity for the construction sector to achieve decarbonization has thrust steel-CLT (cross-laminated timber) composite flooring systems into prominence as an avant-garde amalgamation of sustainability and structural advancement. This review rigorously evaluates the capacity of these hybrid systems to harmonize the carbon-sequestering potential of CLT—which sequesters 135% of its mass in CO<sub>2</sub>—with the unparalleled tensile strength of steel, realizing a 60% reduction in embodied carbon and accommodating spans of 12 meters. Nevertheless, their implementation is obstructed by paradoxical issues: the absence of standardized assessments for human-induced vibration thresholds, transport emissions undermining sequestration benefits, and fragmented design regulations inflating expenses by 15-20%. Utilizing global case studies—from Amsterdam’s Haut Tower to prototypes at the University of Warwick—this review integrates advancements in bio-hybrid materials (such as self-healing timber coatings), AI-enhanced design methodologies, and policy frameworks (for instance, the EU’s Timber Covenant). Significant findings indicate that demountable steel-CLT connections facilitate 90% material reuse, while AI-optimized grain orientation enhances vibration damping by 25%. However, financial impediments such as $20-30/sq.ft cost premiums and regional shortages of CLT remain prevalent. By advocating for carbon pricing mechanisms, localized supply chains, and interdisciplinary educational initiatives, this review establishes steel-CLT systems as a feasible foundational element for carbon-neutral urban development, dependent upon the resolution of technical, economic, and cultural disparities.