Investigation of Large‐Diameter CFRP Tie Rods Using Large‐Tow Carbon Fibers: Design, Application, and Integrated Life Cycle Assessment

Carbon Fiber Reinforced Polymer (CFRP) is recognized for its outstanding mechanical properties and environmental sustainability, yet its economic viability has limited broader adoption. With the decreasing cost of large‐tow carbon fibers, a reassessment of CFRP's overall sustainability is warranted. This study investigates the use of large‐tow CFRP tie rods as replacements for steel diagonal connections in the roof structure of Xiang'an Airport. A 20 mm diameter CFRP rod was developed using 48 K fabric and a single‐process extrusion method, incorporating wedge anchorages and adjustable/fixed U‐connectors. Mechanical tests confirmed an ultimate tensile strength of 2304 MPa, an elastic modulus of 158 GPa, sustaining 109% of the theoretical ultimate load after 50 times cyclic loading. Compared with steel, the CFRP tie rod achieved a 33% reduction in diameter, 65% weight savings, and a 25% decrease in installation time. Life cycle assessments were conducted considering both life cycle carbon emissions (LCCE) and life cycle cost (LCC). Although the LCC of CFRP is 1.5 times higher than steel, its LCCE is only 53.5% of that of steel. The carbon emission intensity (CEI) per unit cost is reduced by 80%, indicating that large‐tow CFRP tie rods offer a more sustainable alternative for structural applications.