Mechanical Efficiency and Cost-Effectiveness of Alternative Textile Composite Grid Reinforcements in Autoclaved Aerated Concrete (AAC) Lintels

Autoclaved aerated concrete (AAC) lintels are conventionally reinforced with steel grids, which are susceptible to long-term corrosion due to moisture penetration and carbonation through the open porous matrix. This study investigates the structural performance and feasibility of AAC lintels reinforced with alternative composite grids—carbon mesh, glass rebar grids, and glass mesh—as corrosion-resistant substitutes for steel. Specimens were evaluated through four-point bending tests to evaluate flexural behavior, capacity, toughness, and production costs. The steel grid achieved the highest peak load (17.20 kN) but showed brittle failure. Carbon mesh showed a pseudo-ductile plateau over a wider deflection range (10.30 mm) and the highest flexural toughness (81,308 N·mm), yielding an 18% toughness increase over the steel control. The glass rebar grid provided the largest displacement tolerance (15.5 mm) through crack-bridging, while lightweight glass mesh showed limited load capacity (3.64 kN). Economic analysis showed that the ready-to-use nature of textile meshes simplifies handling, reduces labor, lowers pre-processing costs to about €0.004 per unit, and eliminates anti-corrosion coatings. Within the tested configurations (n = 3), these findings indicate that carbon mesh and glass rebar grids represent viable alternative reinforcement systems for AAC lintels, offering adequate load-bearing capacity, enhanced deformation tolerance, and simplified, corrosion-free pre-processing.